Max Amp Draw With Rc Plane Battery

Foreword

This guide, written over the grade of years, has one sole aim: to brainwash hobbyists new and erstwhile virtually LiPo batteries with a focus on prophylactic. The guide and I have been criticized over the years for "misleading" people on the dangers of LiPo batteries or the practices of charging, using, and storing them. Some of these criticisms were justified, and the guide changed to better reflect reality (come across the changelog at the bottom for details of those changes). Some of the attacks were non justified and came from those in the manufacture whose business I was disrupting by recommending against certain practices. In those cases, the guide was not changed. My only interest in keeping those who come to us for guidance safe and educated, with no exceptions. So read on, learn, ask questions, and exist safe!

Here are another articles you may find interesting later on yous learn about LiPo batteries:

A Guide to Traxxas' Batteries & Chargers

At present that purchasing a Traxxas vehicle also means using their batteries and chargers, agreement Traxxas' batteries, chargers, and accessories is of import for all Traxxas owners. In this guide, we'll become over Traxxas' batteries — both Nickel-Metal Hydride and Lithium-Polymer — the Traxxas iD applied science, and finally, Traxxas' chargers and how to apply them.

R/C Gearing 101

One of the questions nosotros get asked a lot has to do with gearing; how information technology works, what happens when I put this gear on that, can I get ameliorate runtimes if I modify the gearing, etc. Information technology can be a flake of a nightmare to effigy out how best to gear your truck, only with a little math and a calculator, you can exist a gearing expert in no time — or at to the lowest degree proficient plenty to achieve what you lot're shooting for.

How to Maximize Your Run Time

One affair that is universal for anyone that runs electric R/C cars and/or trucks is a desire for more than run time. It seems like at that place is no such affair equally besides much run fourth dimension, but there is an optimal mode to amend the amount of running time yous can get with your R/C vehicle. This guide seeks to explain those all-time practices in an approachable style. And so allow'southward get into information technology!

Introduction

Lithium Polymer (AKA "LiPo") batteries are a type of battery now used in many consumer electronics devices. They accept been gaining in popularity in the radio control industry over the last few years and are now the most popular choice for anyone looking for long run times and loftier power. LiPo batteries offer a wide array of benefits, but each user must decide if the benefits outweigh the drawbacks. For more and more people, they practise. In my personal opinion, in that location is nothing to fear from LiPo batteries, so long every bit you follow the rules and treat the batteries with the respect they deserve.

This guide was written afterward many hours of research. It is as accurate every bit I tin can brand it without actually existence a chemic engineer (though in researching this commodity, I did talk to a few of them). That said, this guide isn't intended to be taken equally definitive. Information technology is a living certificate, and equally common knowledge regarding LiPo batteries changes, then too volition this guide.

Let'southward outset talk near the differences between LiPo batteries and their Nickel-Cadmium and Nickel-Metal Hydride counterparts.

LiPo Batteries

Pros

• Much lighter weight, and can be made in most whatever size or shape.

• Much college capacities, allowing them to hold much more energy.

• Much higher belch rates, meaning they pack more dial.

Cons

• Much shorter lifespan; LiPos boilerplate only 150–250 cycles.

• The sensitive chemical science tin lead to a fire if the battery gets punctured.

• Demand special care for charging, discharging, and storage.

NiMH Batteries

Pros

• Longer lifespan than LiPos, usually into the 1,000 cycles range

• Much less sensitive, and doesn't usually pose a fire risk

• Simpler chargers and routines are required for use.

Cons

• Much heavier, and limited on size.

• Lower average capacity, and less efficient overall.

• Lower discharge rates; they lack tremendous punch.

What Practise All the Numbers Hateful?

The way we define any battery is through a ratings system. This allows us to compare the backdrop of a battery and help us determine which battery pack is suitable for the need at hand. There are three main ratings that y'all need to be aware of on a LiPo battery.

So what does it all mean? Allow's intermission information technology down and explain each 1.

Voltage / Prison cell Count

A LiPo cell has a nominal voltage of iii.7V. For the 7.4V battery above, that ways that there are two cells in series (which means the voltage gets added together). This is sometimes why you lot will hear people talk nearly a "2S" battery pack - it means that there are ii cells in Due southeries. And then a ii-cell (2S) pack is vii.4V, a iii-jail cell (3S) pack is 11.1V, and and so on.

Almost Nominal Voltages

I thought (mistakenly) that this was mutual knowledge, only subsequently a handful of emails on the topic, information technology was clear I needed to clarify what nominal voltage is.

Nominal voltage is the default, resting voltage of a battery pack. This is how the bombardment industry has decided to talk over and compare batteries. It is not, nevertheless, the total charge voltage of the prison cell. LiPo batteries are fully charged when they attain 4.2v/cell, and their minimum rubber charge, as we will discuss in particular afterwards, is 3.0v/cell. 3.7v is pretty much in the centre, and that is the nominal charge of the jail cell.

In the early days of LiPo batteries, you might take seen a battery pack described as "2S2P". This meant that there were really four cells in the battery; two cells wired in series, and two more wired into the get-go two batteries in parallel (parallel meaning the capacities go added together). This terminology is not used much nowadays; mod technology allows united states of america to accept the individual cells concord much more than energy than they could simply a few years ago. Fifty-fifty so, it can exist handy to know the older terms, but in case you run into something with a few years on it.

The voltage of a battery pack is essentially going to make up one's mind how fast your vehicle is going to go. Voltage directly influences the RPM of the electric motor (brushless motors are rated by kV, which means 'RPM per Volt'). So if you have a brushless motor with a rating of 3,500kV, that motor will spin 3,500 RPM for every volt you apply to it. On a 2S LiPo battery, that motor will spin around 25,900 RPM. On a 3S, it volition spin a whopping 38,850 RPM. So the more than voltage yous have, the faster you're going to become.

Capacity

The capacity of a battery is basically a measure of how much ability the battery can hold. Think of information technology every bit the size of your fuel tank. The unit of measurement of measure here is milliamp hours (mAh). This is proverb how much drain tin can exist put on the battery to discharge it in one 60 minutes. Since nosotros usually discuss the drain of a motor organisation in amps (A), hither is the conversion:

1000mAh = ane Amp Hour (1Ah)

I said that the capacity of the battery is like the fuel tank - which means the chapters determines how long you tin run earlier you have to recharge. The higher the number, the longer the run fourth dimension. Airplanes and helicopters don't really have a standard capacity, because they come in many dissimilar sizes, but for R/C cars and trucks, the average is 5000mAh - that is our most popular bombardment here in the store. Merely there are companies that make batteries with larger capacities. Traxxas fifty-fifty has i that is over 12000mAh! That's huge, simply in that location is a downside to large capacities too. The bigger the capacity, the bigger the physical size and weight of the bombardment. Another consideration is rut build upwards in the motor and speed control over such a long run. Unless periodically checked, you can easily burn down up a motor if it isn't given enough fourth dimension to cool downwards, and most people don't stop during a run to cheque their motor temps. Go along that in mind when picking up a battery with a large capacity.

Q: Why practice nosotros utilize voltage, and not capacity, to determine how charged a battery is?

A: The reason we use voltage to determine the charge level of a battery stems from our difficulty in measuring capacity. Voltage is simple to measure out — if you've always used a voltmeter to measure a AA bombardment, you understand how fiddling it is to measure voltage.

Chapters, even so, is nearly impossible to measure accurately. We can mensurate how much energy is going into a battery (at to the lowest degree somewhat accurately), just nosotros can't measure how much is actually in the bombardment.

Think of it like beakers of water. For voltage, the beaker is transparent, and nosotros can easily see the amount of water in the chalice in the aforementioned fashion nosotros can mensurate voltage whenever we like. On the other paw, nosotros have the chalice representing capacity, and information technology'southward opaque — nosotros can't see through it, so the but way to know how much is within is to empty it and measure the water (energy) equally it's leaving the chalice (battery).

Considering amperage and voltage are intertwined, as we will discuss later in item, the voltage of a bombardment does correlate, approximately, to the capacity left in the bombardment, and while there are times when the voltage can deceive y'all, in general, it'due south okay to rely on voltage as our main measure of how full a battery is.

This question was asked by Donald via email, and made consummate sense to include my respond to him on the guide. Cheers, Donald!

Discharge Rating ("C" Rating)

Voltage and Capacity had a direct touch on on sure aspects of the vehicle, whether it's speed or run time. This makes them easy to understand. The Discharge Rating (I'll be referring to it as the C Rating from now on) is a bit harder to empathise, and this has lead to it beingness the virtually over-hyped and misunderstood aspects of LiPo batteries.

The C Rating is simply a measure of how fast the battery tin be discharged safely and without harming the battery. One of the things that makes it complicated is that it's non a stand-alone number; it requires you to also know the capacity of the battery to ultimately effigy out the safe amp draw (the "C" in C Rating actually stands for Capacity). Once you know the capacity, it's pretty much a plug-and-play math problem. Using the above battery, here's the manner you discover out the maximum safe continuous amp describe:

50C = 50 x Chapters (in Amps)
Calculating the C-Rating of our example bombardment: 50 x 5 = 250A

The resulting number is the maximum sustained load you can safely put on the battery. Going higher than that will effect in, at best, the deposition of the bombardment at a faster than normal stride. At worst, it could burst into flames. So our example battery tin handle a maximum continuous load of 250A.

Most batteries today have 2 C Ratings: a Continuous Rating (which we've been discussing), and a Burst Rating. The Burst rating works the same way, except it is only applicative in 10-2d bursts, not continuously. For case, the Burst Rating would come into play when accelerating a vehicle, but not when at a steady speed on a straight-away. The Burst Rating is almost always college than the Continuous Rating. Batteries are unremarkably compared using the Continuous Rating, not the Burst Rating.

There is a lot of vitriolic comments on the Internet almost what C Rating is best. Is it best to get the highest you tin? Or should you get a C Rating that'south just enough to comprehend your need? In that location isn't a simple answer. All I can requite you is my accept on the issue. When I prepare upwards a customer with a LiPo battery, I commencement find out what the maximum current his or her application will describe. Allow'southward look at how that works.

Allow's assume that our example customer is purchasing a Slash VXL R/C truck. That motor, according to Traxxas, has a maximum continuous current draw of 65A and a burst depict of 100A. Knowing that, I can safely say that a 2S 5000mAh 20C LiPo will be sufficient, and volition in fact have more power than we need. Recall, it has a maximum prophylactic continuous discharge rating of 100A, more than than enough to handle the 65A the Velineon motor will describe. Similarly, the Burst Rate of 150A hands covers the 100A the motor could draw.

However, the ratings on the motor aren't the whole picture. The way the truck is geared, the terrain the truck is driving on, the size of the tires, the weight of the truck... all of these things have an bear on on the final draw on the battery. It's very possible that the final describe on the battery is higher than the maximum motor depict. Then having that little fleck of overhead is crucial, because you can't easily effigy out a difficult number that the truck will never get over.

For nigh applications, a 20C or 25C bombardment should be fine. But if you're driving a heavy truck, or you're geared up for racing, or you take a large motor for 3D flying applications, you should probably start around a 40C battery pack. Just since at that place is no like shooting fish in a barrel way to effigy this out, I encourage you to talk to your local hobby store to have them help decide which bombardment pack is right for your application.

Internal Resistance: The Mystery Number

There is ane very important rating nosotros haven't talked about yet: Internal Resistance (or IR). Trouble is, you won't discover the IR rating anywhere on the battery. That's because the internal resistance of a battery changes over fourth dimension, and sometimes because of the temperature. Still, merely because you lot can't read the rating on the battery doesn't mean it isn't important. In a way, the internal resistance is one of the most important ratings for a battery.

To understand why the IR is important, we have to understand what it is. In simple terms, Internal Resistance is a measure of the difficulty a battery has delivering its energy to your motor and speed control (or any else you lot have a battery hooked upward to). The college the number, the harder it is for the energy to reach its preferred destination. The free energy that doesn't "go all the fashion" is lost as rut. So the internal resistance is kind of a measure of the efficiency of the battery.

Internal Resistance is measured in milliohms (mΩ).
1,000 milliohms is equal to i Ohm (Ω)

Measuring the IR of your battery requires a special toolset. You either need a charger that will measure it for you or a tool that specifically measures internal resistance. Given that the simply tool I have found for this (at least in the hobby world) is most every bit expensive equally a charger that does this for you, I'd go with a charger for this process. Some chargers measure out each cell's IR separately, and some measure the entire battery pack as a whole. Since internal resistance is a cumulative effect, and the cells are wired in series, if you lot have a charger that does each prison cell independently, yous need to add up the IR values of each cell, like this:

Suppose we have a 3S (3-cell) LiPo battery, and the measuring the cells independently yields these results.

Cell 1: 3 mΩ     Cell 2: 5 mΩ     Cell 3: four mΩ

To find the total internal resistance for the battery pack, we would add upwardly the values for the 3 cells.

3Ω + 5Ω + 4Ω = 12 mΩ

For a charger that measures the pack as a whole, all you would meet is the 12 mΩ - the residue would be done for yous - behind the scenes, as it were. Either fashion, the goal is to have the IR for the entire pack.

The get-go reason internal resistance is important has to practise with your bombardment'southward health. Every bit a LiPo battery is used, a build up of Li2O forms on the inside terminals of the battery (we'll go more than in depth on this later in the Discharging section). As that build upward occurs, the IR goes up, making the battery less efficient. Later many, many uses, the battery will simply habiliment out and be unable to concord on to whatsoever energy you put in during charging - most of it will be lost as estrus. If you've ever seen a supposed fully charged bombardment discharge almost instantly, a high IR is probably to blame.

To empathise how Internal Resistance works in R/C applications, first nosotros have to empathize Ohm'southward Law. It says that the electric current (Amps) through a conductor between two points is directly proportional to the difference in voltage across those two points. The modernistic formula is as follows: Amps = Volts / Resistance. In the formula, the resistance is measured in Ohms, not milliohms, and then we'd have to catechumen our measurements. If nosotros use our previous 3S LiPo, and plug it into the equation along with a 1A depict, we tin find out how much our battery pack'south voltage volition drib as a result of the load. Beginning, we have to change the equation to solve for volts, which would look like this:

Amps x Resistance = Volts

So plugging in our numbers and solving the equation would look like this:

1A ten 0.012 Ω = 0.012V

So our battery would experience a tiny driblet in voltage when a 1A load is applied. Considering our 3S LiPo is around 12.6V when fully charged, that's not a big deal, right? Well, let'due south see what happens when we increment the load to 10A.

10A ten 0.012 Ω = 0.120V

Now we see that when nosotros increased the load 10X, nosotros also increased the voltage drib 10X. Only neither of these examples are very "real globe". Let's apply the Slash VXL from the previous department and plug those numbers in. If you lot recall, our Velineon motor has a maximum continuous current rating of 65A. Let'due south presume we manage to hit that mark when driving and employ that.

65A 10 0.012 Ω = 0.780V

Wow, more than iii/4 of a volt! That's around half-dozen.2% of the total voltage of our battery pack. Pretty respectable, but it's still a reasonable drop in voltage.

"And so, yeah, the voltage drops. But so what? What does that actually mean? How does information technology effect my R/C vehicle?" Well, allow'due south continue on with our example to bear witness you.

The Velineon motor our Slash VXL uses has a Kv rating of 3500. That means it spins 3,500 RPM per volt. On a fully charged 3S LiPo we'll come across this (assuming no voltage drop):

12.6V x 3500RPM = 44,100 RPM

At present, assuming nosotros tin can hit that 65A draw on our unloaded motor (which we can't in real life, but for the purposes of demonstration we can), hither's the RPM on the aforementioned motor with our voltage drop from earlier:

xi.82V x 3500RPM = 41,370 RPM
Deviation of 2,730 RPM

Encounter the drop in operation? That's the effect Ohm'south Law has on our hobby. A lower internal resistance means your car or truck or airplane or boat or helicopter goes faster and has more than power.

This begs the question: how low should it be? Unfortunately, there's no like shooting fish in a barrel answer for this. It's all dependant on your use case and battery. What is great for i battery may be terrible for another. Based on my online inquiry, combined with my ain experience and findings, I would say, equally a general rule, a per jail cell rating of between 0-vi mΩ is as skillful as it gets. Between 7 and 12 mΩ is reasonable. 12 to 20 mΩ is where you start to see the signs of aging on a battery, and beyond 20mΩ per cell, you lot'll want to start thinking about retiring the battery pack. Just this is just a guide - at that place is no hard rule set here. And if your charger doesn't give you the per cell measurements, you'll take to divide your full count by the number of cells in your battery to go an approximate per cell rating.

Internal Resistance and C-Rating

In that location are many people out at that place that believe a higher C-Rating volition make their vehicle perform meliorate. We know from our previous discussion on C-Ratings that you lot need to account for the ability draw your motor has when picking out the right C-Rating for your bombardment, but does more equal better? Many people say yes.

But in that location isn't annihilation intrinsic to the C-Rating that substantiates their claims. It's simply not true that a higher C-Rating makes your machine or airplane faster.

Nonetheless, there is a correlation between the C-Rating of a bombardment and the internal resistance of that battery. In general, batteries with a higher C-Rating besides have a low internal resistance. This isn't ever the case, as in that location are always variances in manufacturing, but the general thought seems to hold true, and a lower IR will make a car or airplane faster.

This is a example of correlation not equalling causation. It's really the internal resistance making a battery faster, non the C-Rating.

Proper Care & Treatment: Charging

Bombardment and Residue Board

It's important to utilise a LiPo uniform charger for LiPos. As I said in the Introduction, LiPo batteries require specialized care. They charge using a system chosen CC/CV charging. It stands for Constant Current / Constant Voltage. Basically, the charger will keep the current, or charge rate, abiding until the bombardment reaches its top voltage (4.2v per cell in a battery pack). And then information technology will maintain that voltage, while reducing the current. On the other hand, NiMH and NiCd batteries charge best using a pulse charging method. Charging a LiPo battery in this way can have damaging effects, so it'south of import to accept a LiPo-compatible charger.

The 2nd reason that you need a LiPo-compatible charger is balancing. Balancing is a term nosotros use to describe the act of equalizing the voltage of each jail cell in a battery pack. We rest LiPo batteries to ensure each jail cell discharges the same amount. This helps with the operation of the battery. It is besides crucial for safety reasons - but I'll get to that in the section on discharging.

While there are stand-solitary balancers on the marketplace, I recommend purchasing a charger with born balancing capabilities, using a rest board like the one pictured to the right. This simplifies the process of balancing, and requires ane less thing to be purchased. And with the price of chargers with built-in balancers coming down to very reasonable levels, I tin can't think of a reason y'all would not want to simplify your charging ready. We'll talk more nearly chargers in the adjacent section.

Well-nigh LiPo batteries come with a connector called a JST-XH connector on the remainder tap. Ane of the big issues with this connector is it's lack of surface area; namely, 1's inability to get a good grip on the connector. This makes information technology hard to unplug from a balance lath, and a user normally just ends up pulling on the wires. This can break the connector, and potentially brusk out the battery. A unique product, called Residue Protector Clips (or AB Clips) is a not bad manner to solve this problem. They clip around the balance connector, and give a user more space to grab on to the information technology. They are usually inexpensive, and a great fashion to prevent residual connector fatigue. To the left, you can see a rest connector with and without the Balance Protector Clips.

Most LiPo batteries need to exist charged rather slowly, compared to NiMH or NiCd batteries. While nosotros would routinely charge a 3000mAh NiMH battery at four or five amps, a LiPo battery of the aforementioned capacity should be charged at no more than iii amps. Merely as the C Rating of a bombardment determines what the rubber continuous discharge of the bombardment is, there is a C Rating for charging as well. For the vast bulk of LiPos, the Charge Rate is 1C. The equation works the aforementioned way as the previous discharge rating, where 1000mAh = 1A. So, for a 3000mAh bombardment, we would want to accuse at 3A, for a 5000mAh LiPo, nosotros should set the charger at 5A, and for a 4500mAh pack, 4.5A is the right charge rate.

The safest charge rate for most LiPo batteries is 1C, or ane x capacity of battery in Amps.

Notwithstanding, more and more LiPo batteries are coming out these days that advertise faster charging capabilities, like the example battery nosotros had above. On the bombardment, the characterization says it has a "3C Charge Rate". Given that the battery's capacity is 5000mAh, or v Amps, that means the battery can be safely charged at a maximum of 15 Amps! While it's all-time to default at a 1C charge rate, always defer to the bombardment's labeling itself to determine the maximum safe charge charge per unit.

Due to the potential for burn when using LiPo batteries, regardless of the likelihood, certain precautions should be taken. Always have a fire extinguisher nearby; it won't put out a LiPo fire (as I will further explain below, LiPo fires are chemical reactions and are very hard to put out). Merely a burn down extinguisher will comprise the burn and end it from spreading. I prefer a CO2 (Carbon Dioxide) extinguisher - it helps to remove oxygen from the burn site, and will as well cool down the bombardment and surrounding items. Another condom precaution is to charge the LiPo in a burn-resistant container. Most people opt toward the LiPo Bags on the market place today, like the ane pictured to the left. They are a flake pricy, but are more than portable than other solutions. Finally, never charge your LiPo batteries unattended! If something does happen, you needs to be around to react rapidly. While you don't have to always be in the same room, yous shouldn't go out the firm, or get mow the lawn, or anything else that volition forestall y'all from taking activeness should the bombardment catch fire.

NEVER Leave a Battery Charging Unattended!

Picking Out the Right Charger

At the fourth dimension of this writing, I consider the Dynamite Passport P1 Mini Charger (pictured to the left) to be one of the best values on the market. It'southward a multi-chemistry charger, which ways it can accuse NiMH, NiCd, and Pb Acid batteries besides equally LiPo batteries. It can fifty-fifty accuse the newest LiFe batteries that some use for receiver packs in airplanes and cars. It has a built-in balancer that handles up to 4S LiPo batteries and can charge upward to six amps. It's a groovy charger for the price. It's not every bit loftier-ability every bit some LiPo users may need, though, since it just operates at lx watts. So higher jail cell count batteries may non charge very fast on the P1.

If you demand to charge multiple batteries at the same time, the Ultra Power UP240AC Plus charger is probably the all-time bet. Priced at around $190, information technology has all the capabilities of the KX80, merely with iv independent 50W charge ports. This ways you can charge upwards to four batteries at one fourth dimension! If you demand more wattage, the Dynamite Prophet Sport Quad 100W is the way to get, with four 100W charge ports. In fact, nosotros use the 100W version equally our go-to charger here in the shop.

If you have large-capacity batteries, big prison cell counts, or higher charging rates, you may want to find a charger that operates on higher wattages. As mentioned, the P1 Passport Air conditioning/DC charger works on 60 watts (60W). Each port on the Ultra Power quad charger is 60W (if using them all at the aforementioned time). What does this mean to you? Well, allow's await at how watts, amps, and voltage work together.

Watts = Voltage x Amperage

Come across, wattage, voltage, and amperage are intertwined. Yous tin can convert voltage to amperage, and vice-versa. This is of import in determining what kind of charger yous demand. Permit me show you how.

Let'southward say that I have a 6S 5000mAh LiPo bombardment, and I want to charge it at 1C, which would be 5A. If I have a KX80 Air-conditioning/DC Charger, I can set up the charger to charge at 5A for a 6S battery. But when I go to charge the battery, the most information technology always charges at is around 3.5A. What gives? If we use the formula above, we tin can plug in our voltage (22.2V) and our Amperage (5A) and we get this:

22.2v 10 5A = 111W

So the formula is maxim that if nosotros desire to charge our 6S 5000mAh LiPo pack at 5 Amps, we would demand a charger that is capable of delivering at least 111 Watts of power. Our Kinexsis KX80 can only evangelize lxxx Watts.

So you lot tin see why a college wattage charger might be important if you want to charge larger batteries quickly. For these kinds of chargers, right now I'd have to recommend the Dynamite Passport Ultra Force 220W Touch. (pictured left). Like the Kinexsis KX80, it's a single-port, multi-chemistry charger. Unlike the KX80, though, it is capable of a whopping 220-Watt output, and a accuse rate of upward to 15A. Better yet, unlike many similar chargers of this power, the Passport Ultra Force is AC/DC, so there's no boosted power supply to purchase!

Equally always, information technology's best to talk to your local hobby shop and have them set up yous up with a charger that will fit your needs. Local back up is always a handy affair!

Parallel vs. Series Charging

A wonderful gentleman from the Netherlands contacted me recently asking virtually parallel charging versus series charging. He wanted to know how best to charge half dozen of his single-jail cell LiPo batteries at the same time. Parallel charging adapters are readily available, then that must be the best mode, right?

Absolutely not! Parallel charging can be very dangerous. Even experts from well-known battery manufacturers "consider parallel pack charging to be highly dangerous and should not exist attempted fifty-fifty by experienced users". The problem with parallel charging (or even using your batteries in parallel) is that, when hooking up batteries in parallel, yous are doubling the capacity of the batteries while, and this is important, maintaining the voltage of one of the individual batteries. What this means is that your charger, which commonly monitors the bombardment while charging to prevent overcharging, cannot see all of the individual batteries' voltages - it can just run into one.

Another trouble with parallel charging is the inequality of the batteries. If the two batteries (and the cells contained therein) were from the exact aforementioned production lot, had the exact aforementioned chemical limerick and age and charge history and everything else - in other words, if they were completely identical - parallel charging would be okay. Merely a consumer (that's you) will never be able to replicate those conditions, or even come close. The more those parameters differ, and considering the questionable balance charging techniques that many bombardment chargers use, the higher the chance of over charging and thermal runaway (more on that in the next section).

Simply what almost batteries that are built in parallel? Doesn't the fact that batteries are onetime constructed in parallel hateful that parallel charging is safe?

Similar I said before, if you can match all those parameters to be identical, parallel charging is okay. At the mill where they make the packs, manufacturers are constantly monitoring and testing the materials that make upward the cells. Each cell is labelled with a UPC code that contains the unabridged chemic makeup and history for that cell. When a manufacturer assembles a battery, a computer scans and sorts the cells into compatible matches. Only so is it safe to parallel accuse these cells. However, when yous charge a LiPo battery at home, fifty-fifty if it is already constructed in parallel, you don't demand whatsoever fancy parallel charging boards - the work is already washed for you lot, and you simply need to accuse it as you would a normal battery.

Please, please, don't employ parallel charging cords. There is no safe style to utilise these. Parallel charging simply tempts fate. You will exist able to detect thousands of successful attempts to parallel charge batteries around the web. These are just people that have not nonetheless managed to burn down their home downwardly. Every battery practiced I have talked to agrees on this.

Series charging is the safer of the ii methods (meaning it's no less dangerous than straight-upward normal charging) IF you set up your charger the correct fashion. If y'all want to charge six unmarried-jail cell LiPo batteries — that are all the same capacity — you can wire them up in series, set upward your charger every bit if information technology were a six-cell LiPo, and balance charge your LiPos. The human activity of residual charging them is essentially making the charger individually charge each cell, making sure they are all kept at prophylactic levels. If you only have a single-port charger, series charging is the only safety way to charge multiple batteries at the aforementioned fourth dimension, but wiring them upwardly properly is pretty circuitous and not something a beginner should try.

And the absolute best fashion to charge multiple batteries at the aforementioned time is to have a multi-port charger, similar the Dynamite Prophet Sport Quad mentioned above. If you lot find yourself needing to charge many batteries at once, do the smart thing and buy a charger (or chargers) that will fit your needs.

And cheers to Thiemo for the question!

Proper Care & Handling: Discharging (Using the Battery)

LiPo batteries offering enough of power and runtime for united states of america radio control enthusiasts, but that power and runtime comes at a cost. LiPo batteries are capable of communicable burn down if not used properly - they are much more delicate than the older NiMH/NiCd batteries. The problem comes from the chemical science of the battery itself.

Lithium-Polymer batteries comprise lithium, an alkali metal, which reacts with water and combusts. When heated, Lithium also combusts when reacting with oxygen. The process of using the battery, in the sometimes extreme ways that we do in the R/C world, causes in that location to be excess atoms of Oxygen and excess atoms of Lithium on either finish (the cathode or anode) of the battery. This can and does cause Lithium Oxide (Li2O) to build upwardly on the anode or cathode. Lithium Oxide is basically lithium corrosion, or lithium "rust". The Li2O causes the internal resistance of the battery to increase. The practical result of higher internal resistance is that the battery will rut upward more during use.

Higher Internal Resistance = College Operating Temperature

Equally we touched on earlier, some modern chargers can read the internal resistance of the battery in milliohms (mΩ). If you take one of these chargers, you can get a sense of how your LiPos are performing, and how their internal resistance increases every bit they age. But keep rails of the internal resistance reading each time y'all charge your bombardment, and chart the increase over time. You lot will see how just the procedure of using the LiPo bombardment begins to wear information technology out.

Estrus causes the excess oxygen to build upwards, and somewhen the LiPo pack begins to swell. This is a good time to cease using the battery - its trying to tell you that it has come up to the end of its life. Further apply can be unsafe. After the pack has bloated, continued apply tin can crusade even more heat to be generated. At this point, a process chosen Thermal Delinquent occurs.

A Swelled, or Puffed, LiPo

Thermal Runaway is a self-sustaining reaction that is accelerated by increased temperature, in turn releasing energy that further increases temperature. Basically, when this reaction starts, information technology creates heat. This heat leads to a product that increases resistance (more than Li2O), which causes more estrus, and the process continues until the battery bursts open from the force per unit area. At this point, the combination of heat, oxygen, and the humidity in the air all react with the lithium, resulting in a very hot and unsafe burn.

Even so, even if you lot stop using the bombardment when it swells, y'all still have to render it safe (a process I'll get into after on in the LiPo Disposal section). If you lot puncture a LiPo that has swollen and nevertheless has a charge, it tin still take hold of fire. This is because the unstable bonds that be in a charged battery are in search of a more stable state of existence. That's how a battery works; you destroy a stable chemical bail to create an unstable chemical bond. Unstable bonds are more apt to release their energy in the pursuit of a more than stable bail.

When a LiPo is punctured, the lithium reacts with the humidity in the atmosphere and heats up the battery. This estrus excites the unstable bonds, which break, releasing free energy in the form of estrus. The Thermal Delinquent starts, and you again get a very hot and dangerous fire.

The entire procedure of building up that lithium oxide, in a perfect world, takes around 300-400 charge/discharge cycles to reach a tipping point. A typical lifetime of a LiPo bombardment is closer to 150-250 cycles, because when we estrus the batteries up during a run, or discharge them lower than 3.0 volts per cell, or physically harm them in whatever way, or allow water to enter the batteries (and I mean inside the foil wrapping), it reduces the life of the bombardment, and hastens the build upwardly of Li2O.

In light of this, most manufacturers have taken to putting a Low Voltage Cutoff (LVC) on their speed controls. The LVC detects the voltage of the battery, and divides that voltage by the prison cell count of the battery. So it would see a fully charged 2S LiPo equally eight.4V, or 4.2V per prison cell.

This is where the advantage of balancing comes in. Considering the speed control does not read off the residue tap, it cannot know the verbal voltages of each prison cell within the bombardment. The speed command tin can just presume that the cells of the battery are all equal. This is of import because, as I mentioned above, discharging a LiPo cell lower than 3.0V causes a usually permanent deposition of the cell's ability to absorb and retain a accuse.

A LiPo prison cell should NEVER exist discharged below 3.0V

The LVC works to cut-off the motor of the vehicle (or in some cases, pulse the motor) to warning yous to a nearly-depleted battery pack. It uses the full voltage of the battery as its reference. Most LVCs cut-off around 3.2V per cell. For our ii-cell example bombardment, that would be vi.4V. Only if our battery isn't balanced, it's possible for the total voltage to be higher up the cutoff threshold, yet still take a prison cell below the three.0V danger zone. Ane cell could be iii.9V, while the other could be a 2.8V. That'south a total of 6.7V, which means the cut-off would not engage. The vehicle would continue to operate, assuasive yous to further degrade the bombardment. That's why balancing is so of import.

So when running your LiPo, make sure you have the Low Voltage Cutoff enabled, fix up correctly, and certainly don't keep to run it later the LVC has kicked in! Information technology may be a slight nuisance, only information technology's worth indelible so that your LiPo batteries remain in adept health.

Information technology'southward worth noting that near helicopter speed controls and some airplane speed controls do not have a Low Voltage Cutoff, every bit disabling the motor in mid-air wouldn't exist a good idea. For these kinds of applications, information technology's best to set a conservative timer (some aircraft radio systems have a timer function built in) and land when the timer goes off. Whether your R/C vehicle has a LVC or not, it's not a skillful idea to wing until the bombardment dies!

Proper Intendance & Treatment: Storage

In the old days, nosotros used to run our cars or airplanes until the batteries died, and so just prepare the batteries on the shelf at dwelling, waiting for the next time nosotros could employ them. We only stored them dead. Just you should not do that with LiPo batteries. Nor should LiPo batteries exist stored at full charge, either. For the longest life of the batteries, LiPos should exist stored at room temperature at 3.8V per cell. Most modernistic computerized chargers take a LiPo Storage part that volition either charge the batteries upward to that voltage, or belch them down to that voltage, whichever is necessary.

Proper LiPo Storage Voltage = three.8V per cell

I recommend to our customers that they put their LiPo batteries in storage mode after every run. This isn't necessary per se, only it does build up skillful habits. If yous do it every fourth dimension, you lot don't have to worry about whether or not you remembered to put it in storage. I have had many customers come to me with batteries that died because they charged it up, intending to use it, only life got in the fashion and they never remembered to put it back to storage voltage. Lithium-Polymer batteries can be damaged by sitting fully charged for equally little as a week. This doesn't mean they will go damaged every time you lot leave them for over a week. It just means they tin can, and I've seen it happen. And then don't forget to put your LiPos at storage voltage when you lot're done using them.

They should also be stored in a fireproof container of some sort. As I mentioned above, nearly people tend toward leaving their LiPos in a LiPo pocketbook, as they are portable and protect your workshop from catching burn down should the LiPo combust. I have also seen people apply empty ammo boxes, fireproof safes, and ceramic flower pots. Whatsoever yous have (or tin can purchase) that will prevent any fire from spreading will exist worth it in the unlikely event that anything untoward should happen.

I feel the need to reiterate: the most common problem people have with LiPo batteries is a straight result of improper storage . When a LiPo battery sits for a long period of time (and non at proper storage voltage), it tends to belch itself. If it drops beneath 3.0V per cell, the vast majority of LiPo chargers will non charge it. Sometimes, batteries with this problem can be rehabilitated, just only as often, they are a lost cause. Then once more: if you take a 'laissez-faire' approach to the storage of your LiPo batteries, it'southward entirely likely that you will be purchasing new batteries sooner than you think.

LiPo Battery Disposal

Before disposing of your LiPo, cheque to make sure the warranty has expired. Some companies accept one-year replacement warranties that you can take advantage of, but most warranties will exist voided if you lot perform the following steps earlier seeking a warranty replacement.

So you have a bad LiPo bombardment? No one really wants to go on them around (burn hazards that they are). So what is the process to go rid of a bad LiPo battery safely? Let's become through it.

1. Discharge the LiPo battery as far down every bit you safely can. You can practise this a number of ways. Most computerized LiPo chargers have a discharge feature in them. If you don't have a charger with a discharge feature, you can run down the battery in your vehicle - keep in mind that you risk a fire and potentially damaging your vehicle doing this, so take intendance to accept the necessary safety equipment around. Alternatively, you can build your own discharge rig with a taillight bulb and some wire. Only solder a male connector of your choosing to the tabs on a taillight bulb, and plug the bombardment in. Brand certain to take the bombardment in a fireproof container while doing this.

2. Place the LiPo in a salt water bath. Mix table common salt into some warm (not hot) h2o. Go along adding salt until information technology will no longer dissolve in the h2o. Ensure that the wires are all entirely submerged. The salt water is very conductive, and it will essentially short out the battery, further discharging information technology. Leave the battery in the table salt h2o bath for at least 24 hours.

3. Bank check the voltage of the LiPo. If the voltage of the battery is 0.0V, groovy! Move onto the next step. Otherwise, put information technology dorsum in the salt h2o bath for another 24 hours. Continue doing this until the battery reaches 0.0V.

4. Dispose of the battery in the trash. That's right - different NiMH and NiCd batteries, LiPos are non hazardous to the environment. They can be thrown in the garbage with no problem.

Alternatively, if you don't feel like going through this process yourself, yous can bring the battery in to united states of america and we will dispose of it for you at no cost. If yous're not in our surface area, check with your local hobby store to see if they offer a similar service.

Julian from California emailed me to let me know that in his home state, all batteries must be recycled at an authorized battery recycler, so don't throw your LiPo battery in the trash after discharging information technology - seek out a recycler. For more data, see California State's Webpage on the Topic.
Thanks, Julian!

Equipping Your LiPo: Proper Connectors

LiPo batteries have all sorts of power just waiting to be unleashed, and we desire as much of that power to achieve the motor equally possible. Just all too ofttimes, I have customers come up in with a great LiPo bombardment attached to a terrible connector. Bad connectors increase resistance and foreclose all that power from existence used efficiently. And so while it's non specifically about LiPo batteries, let'southward talk nearly connectors a niggling.

Traxxas Connectors

Traxxas' High Electric current Connectors have been gaining in popularity over the terminal few years. These are seen mostly on R/C cars and trucks. The chief appeal of these connectors is the ease of assembly. The terminals are separate from the plastic housing, making them easier for novices to solder. They don't require heat shrink, equally the plastic housing shrouds the terminals completely. They are polarity protected, so they can't be plugged in backward. Recently, Traxxas locked their connectors downwards, and now only they can produce batteries with these connectors.

EC3 Connectors

EC3 connectors came onto the scene considering Horizon Hobby was looking for a connector to replace the Tamiya connector as its standard plug. And so the story goes, Horizon approached Deans with the intent to license the connectors and obtain them at a bulk charge per unit (then they could install them on their batteries at the manufactory). Deans refused to exist "reasonable" in negotiations, and then Horizon was left to come with an culling. They found the EC3 and licensed that connector. From at that place, it's no surprise that the EC3 spread similar wildfire. While they aren't much fun to assemble, they have a sizeable foothold in the R/C airplane market place.

Deans Connectors

Deans Connectors are really the king of connectors. They've been around seemingly forever, and have been the top choice for the discerning R/C enthusiast for quite some fourth dimension now. They are somewhat difficult to solder, especially for novice users. Deans connectors slide together smoothly, and are very well designed. Similar almost every mod connector, they are polarity protected. Currently, they are cervix-and-cervix with Traxxas connectors for the title of most popular connector - Traxxas has the border in the R/C surface category, but Deans dominates in the air.

Tamiya Connectors

Only through the shear force of Tamiya's market place share did these connectors take on their name. Originally called a 'Molex' connector, these connectors were the de facto standard of the hobby industry for years. Popularized by Tamiya in their bazillion R/C cars, these connectors came on every vehicle until very, very recently. Even today, some R/C manufacturers still utilise the Tamiya connector on their vehicles (Axial, I'1000 looking at you lot). This is a terrible connector with lots of resistance. You are more probable to melt these connectors than annihilation else. If you have a LiPo that has a Tamiya connector on it, cut it off and solder on 1 of the above connectors.

XT-60 Connectors

XT-60s have gained a trivial bit of basis in the last few years. So far as I can tell, they were developed by a Chinese company called AMASS, and then HobbyKing either purchased or licensed the patent from them. But any their origin story is, the XT-60 connector is getting some adoption due to their prevalence on the LiPo batteries coming direct out of Red china. Equally far as I know, there aren't many domestic battery manufacturers that use the XT-sixty plug as their default. I practice like the plug; information technology's easy to solder to. It's relatively pocket-size and compact besides. It'southward not my favorite, but I don't listen these connectors. You could do worse.

Anderson Power Poles

These connectors were widespread in the early days of radio control. As most of our stuff is borrowed from other industries, Anderson Power Poles are no dissimilar. Originally designed by the ham radio industry for their 12V DC standard connector, they were quickly adopted in the radio control community. Power Poles are the only plug on this listing that is hermaphroditic, significant that the plug is neither male or female. They are all the same - so no worrying about which gender plug goes on the battery or the speed command. They're much rarer in the R/C world today, merely they are probably my favorite plug. They do take upwards a lot of room, though, and as such, may not be useful in many applications.

Now let'southward talk about balancing plugs. There are many different plugs here also, merely in that location are only two main plugs.

Thunder Ability (TP) Plugs

JST-XH Plug

This plug is as shut to an industry standard as we volition e'er have in a residue plug. It comes on nearly all the major brands, from Traxxas and Venom to E-Flite and Duratrax. Most of the cheap bombardment places out of China use this plug as well. While it's not quite as nice as the Thunder Ability plug beneath, information technology'due south ubiquitous, and that makes it the logical choice for these brands. There are very few manufacturers that don't apply the JST-XH plug for their balance pb. But make sure to unplug it by grasping the plastic housing. Pulling on the wires will virtually certainly pull the wires out of the housing, potentially shorting the battery out.

I bemoaned Thunder Power's choice of residual connector for years. Thunder Power makes some of the nicest (and nearly expensive) LiPo packs in the industry, but their connector is not compatible with 95% of the chargers on the market place, at to the lowest degree out of the box (almost chargers volition crave an adapter from the more mutual JST-XH to the TP connector). That having been said, information technology'south a nicer design, with a little clip on the top of the plug, assuasive the user to unplug the connector much more easily. It'southward hard for me to recommend this connector, as it's merely used on Thunder Ability and Flite Power battery packs. Simply I'll begrudgingly admit information technology's a better plug than the JST-XH.

On Soldering...

Another reader, Aaron, emailed me, suggesting a department on soldering — what to do, what not to practice, etc. I thought this sounded similar a dandy thought. Soldering is as much an art as it is a tool, and there is a right style to solder when y'all're talking most battery packs.

Never Cut Your Positive and Negative Wires at the Aforementioned Fourth dimension: This is a great manner to damage your bombardment pack and run a risk a fire. Cutting both wires at the same time will short out the battery pack, which volition generate a lot of oestrus. Call up of it this way — when a welder completes a circuit and welds ii pieces of metal together, that's called Arc Welding — and the same principal is at play in Arc Welding as it would exist when y'all bear upon positive and negative on your battery together. Cut, solder, and heat-compress (if necessary) 1 wire at a time. Information technology might accept a niggling longer, but it'south far and away the safest mode to solder a bombardment.

Become Your Polarity Correct: One cinch way to destroy a speed control is to solder your connector on backwards. Reversing the polarity is never a expert idea. Exist mindful of the markings on the connector — nigh brands include a simple "+" for positive and "-" for negative to indicate which contact is which. Red is positive and black is negative. If your battery or speed control (or whatever you happen to be soldering) doesn't utilize the ruddy/black paradigm, unremarkably the lightest colour wire is positive and the darkest is negative. If both wires are blackness, await for one of them to have white dashes on it — that'due south the positive wire.

Those are some basic safety tips on soldering. If y'all're not happy with your ability to solder, go along at it! I went from the worst solderer in our shop to the best simply by practicing and taking pride in my work. Similar I said to a higher place, soldering is as much an art equally it is a tool. Keep working at information technology and eventually you'll be amazed at how nice your solder joints await!

Thanks to Aaron for the proffer!

Decision

So there you lot have it - now you know most of what you need to know about LiPo batteries. I brand no claims that this article teaches yous everything there is to know well-nigh LiPos, but hopefully, it helps requite you some insight into how they work. LiPo batteries take the potential to overtake NiMH batteries in general utilize in the next few years, quicker than any battery in history. It is certainly an exciting fourth dimension for the hobby, and things are changing on a frequent basis. Just remember to have fun, and if you don't know something, inquire questions! Find your local hobby shop or R/C club — or even mail service your question to ane of the hundreds of R/C message boards on the interwebs. The only dumb question is the one you don't ask!

Change Log

This guide is a living document. Every bit such, it will alter as new information comes out regarding any relevant topic this guide covers. This is a list of changes and updates fabricated to this guide.

• 05/26/12 - Guide published.

• 12/24/12 - Guide moved to new URL.

• 01/25/14 - Guide revamped and re-organized; added section on chargers; added XT-60s to connector department; updated images.

• 02/26/fourteen - Added section on parallel vs. series charging.

• 03/29/14 - Added section on internal resistance.

• 03/02/15 - Removed department on parallel vs. series charging due to concerns of inaccuracy. Volition be re-instated at a after appointment.

• 03/04/xv - Reinstated parallel vs serial charging section. Inaccuracy criticisms proved to be false.

• 04/18/15 - Updated parallel vs. series charging to reverberate that all batteries must exist same capacity to series charge.

• 07/31/fifteen - Added section on soldering.

• 06/01/xvi - Added department on nominal voltage.

• 02/24/17 - Added department on California battery recycling laws.

• 03/24/17 - Added subsection "Why do we use voltage, and not capacity, to determine how charged a battery is?".

• 12/twenty/18 - Edited for brevity and clarity.

• ten/12/19 - Removed section on Venom Connectors (no longer relevant).

• 03/27/21 - Edited for brevity and clarity.

• 10/09/21 - Added Amazon Chapter links.

Check out our Charger Guides for help using your charger!

Brian Schneider / Brian was the manager, webmaster, & social media guru for Roger's Hobby Center for 17 years.

yazzieshrod1959.blogspot.com

Source: https://rogershobbycenter.com/lipoguide

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