Parallel Charging RC LiPo Batteries - The do NOT Do's

With the high performance RC vehicles that we are all after today, power consumption is about as great as it’s ever been. RC Fast electric boats and RC EDF jets are easily capable of over 100 amps continuous current. Burning through one LiPo pack happens very quickly. To combat this we end up grabbing more battery packs and finding a method to get them charged quickly. This is where Parallel charging comes in.
Charging Specification Requirements
Your charger must be capable of 3 specifications to parallel charge. These 3 items are:
1. Voltage or cell count
2. Total Current set on the Charger
3. Total Wattage based on maximum peak voltage and total charge current.
The do NOT do’s of Parallel Charging:
Do not charge LiPo’s in Parallel with varying charge levels
Do not charge LiPo’s with varying cell counts
Do not force the Balance Adapter to charge the batteries
Do not use resistance data when parallel charging
Do not immediately begin charging your LiPo batteries

[@-never-gonna-give-you-up-]

About the voltage differences between batteries, i would suggest to storage charge your batteries separately after flying, that way whenever you are going to fly, you don't have to worry about balancing out the voltage differences and you can just get right to the charging. That way you don't waste time either since storage charging only takes a couple of minutes per battery 😉

[@DozerBoyRc]

Thank you for the information you provided. You have a way of breaking it down and showing the math used to do so. This is a very good method for relaying information. I don't feel like a fool when watching. After one of your many videos I feel like I'm ready to try and implement what I have learned. At any point I start to feel lost, I simply stop and watch video again, until I can go start to finish on my own. Thank you again for sharing your time and knowledge with us!!! Great vid!! Keep them coming!!

[@RCexplained]

Thanks for the comment DozerBoy!

[@frankdearr2772]

Great topic thanks 👍

[@RCexplained]

Glad you liked it!

[@RHINOTACTICAL]

Very well explained. Thank you.

[@RCexplained]

Glad it was helpful!

[@mikemalherbe7845]

Excellent advice!

[@RCexplained]

Glad you think so!

[@longboarderebright]

thanks for letting me know about plugging in main leads first i was doing balance lead first as i thought it would be safer, but i see your reasoning makes more sense!

[@RCexplained]

Glad it helped

[@RHINOTACTICAL]

yup I did the same thing....corrected now!

[@jumpstartfpv]

Shouldn't that 0.1v limit be for per cell of a battery rather than for the whole battery? This means 0.4v for a 4s and 0.6 for a 6s.

[@ujoel2]

Great stuff! What I don't get though is... If you can charge packs with different capacities because the voltages are going to equalize... Then why do I hear that you can't connect two different capacity batteries in parallel to be used in a device? Or is that incorrect. For example, if connecting batteries in parallel for charging results in equalized voltages and relative charge states, then why would the same not result occur when USING to batteries with different capacities.

[@RCexplained]

The same would occur for batteries of different capacities and same C rating.

[@LawrenceTimme]

If you have 2 identical batteries you use in a 2*3s setup in the car can you charge them in series like a single 6s battery?

[@RCexplained]

Yes you can, provided you are able to figure out a solution for the balance taps.

[@programr101]

Do you have any advice for getting a series harness to charge multiple batteries?

[@RCexplained]

You will need a series balance tap for each pack you plan to charge.

[@1dirtovalracer]

I have an i charger and I was wondering if you're able to use a parallel board to put multiple packs into storage mode?

[@1dirtovalracer]

The packs that I use are 2s batteries

[@RCexplained]

Hi Mike, you can parallel multiple battery packs that start around the same charge state in terms of voltage. When you bring the packs to storage voltage, I'd check to confirm each pack has ended up at storage voltage. Slower charge/discharge rates will give the packs time to all balance out.

[@1dirtovalracer]

@@RCexplained okay cool. I was hoping to maybe use the board as a alternate way instead of having multiple Chargers to use the board to charge multiple batteries and have one charger. The problem is can I charge hard and discharge hard on it without having any issues? For instance a 20 amp charge and 25 amps discharge or 40 amps charge 40 amp discharge? Plus how much longer will it take to charge 4 batteries on the parallel board or would it be the same amount for 4 individual batteries or would it charge as fast as 1 battery?

[@RCexplained]

@@1dirtovalracer it would be fastest to use the parallel board. When I parallel charge I like to slow down the charge rate per battery and give the batteries a bit of time to balance out. Instead of charging 1 battery in 20 minutes I charge 4 batteries in 35 minutes or so for example.

[@1dirtovalracer]

@@RCexplained awesome. Thank you very much I think I'm going to buy myself a couple parallel boards. Probably like the one that you demonstrated the Protek board

[@revparsons3tl]

Hi I've got 2 6s lipo batteries wire them up in parallel 1 is 10.000mh and the other 6600 mh would the total capacity be 16600 or 6600 as you go from the lower one

[@RCexplained]

The total capacity would be the sum of the two packs when wired in parallel.

[@revparsons3tl]

@@RCexplained OK other say the ah need to be the same

[@RCexplained]

@@revparsons3tl it is best if mAh are the same but it does not have to be. This is for wiring batteries in parallel only.

[@SkyGamer911]

I don't understand how it can drain 100 amps when like 5 computers barely uses 16 amps.... Can someone explain me why??

[@RCexplained]

What drains 100A? And 5 computers pulling 16A @ 120v or what?

[@stestar09]

He's referring to your jet amp drain of 100 amps giving 5mins battery time .

[@sioul2006]

Because of the way power is calculated. For the power in Watts we need to multiply Voltage with current. So if your computer demands 1.2 Kilowatts (what a BEAST) and your outlet has 230V You’d decide 1200watts by 230 Volts and get ~ 4.7 Amps. If your LiPo now has 12V for example, and you want to feed a motor that draws 1.2 Kilowatts, you have to decide 1200 Watts by 12Volts and get 100 Amperes the battery needs to provide to deliver the same power.

[@sioul2006]

Divide not decide*

[@viv8687]

My battery is 9.6V 11.7Ah LiFePo4. What setting should i use please. I keep getting low voltage or high voltage. What setting should i charge it? It is 27 cell battery. What should my mAh and V be on my charger? Please help.

[@-never-gonna-give-you-up-]

You aren't charging lipo batteries, you are charging LiFePo4 batteries which is a whole different battery.... If you don't know what you have in your hands i would suggest you first educate yourself about that battery and how it should be charged.