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Charge 4 Lithium Ion Batteries in series? Answered

I have got 4 3.7v 6000mAh lithium ion batteries connected in series with 2 batteries holders. I would like to charge them without taking them out (prefer to seal a unit). Anyone know how to do this (I could connect the 4 "cells" individually to separate input/outputs.)?

Also have 19v 3.16A power supply available to use also for charging (Batteries are for making it portable and plug for the 19v)

Have this ordered if it is useful: 4-Cell Li-ion Li-Po Lithium Battery 18650 Charger Protection Board

Help appreciated


Yup, I can guarantee you that those are fake and probably will not hold a charge for long. Hopefully under normal conditions they will not explode. They might work OK for low-drain devices, things that sip power from the batteries, but if they are recycled cells, internal damage from normal wear and tear in the past would have increased the internal resistance. (which means the voltage will sag when you load them down.)

I recommend tenergy batteries, I got 4 many years ago and they are still working well in my 2000 lumen flashlight! I paid $6 and some change per cell for them, the price has unfortunately gone up though. http://www.amazon.com/Combo-Tenergy-Cylindrical-Rechargeable-Batteries/dp/B001CTUB8E/ref=sr_1_3?ie=UTF8&qid=1448548182&sr=8-3&keywords=tenergy+18650+battery

i got them as they were cheap so if they don't work £4 loss isn't bad I'll just get branded ones like the ones you suggested. Thanks for the info.

They might make nice firecrackers for some occasion if they don't work ;) Just be careful!

Yes you can,

You need a "Balancing Charger" that will charge each cell individually.

The link you provided Seems to be the same thing but I have never heard it be called a "Protection board" before. If you check out the Pic I posted you can see how it should be wired. Just run a wire from every point that two batteries meet, and a larger wire on Each end of the series This will allow the balancing charger to charge each cell equally.

Black and yellow charges cell #1

Yellow and Green, cell #2

Green and red are cell #3

Then the two larger wires on the output that connect the whole series together.

If you are using 4 cells then you will need a 5-pin connector to charge it with, and a second 2-pin connector for the series output.

** Be sure these batteries are single cell units**

If there is more then one cell in each pack then this won't work. Do you have the Doc's on the batteries handy?


Yeah those definitely look fake, You can still wire them up like the diagram says though. shouldn't be a problem

OK thanks. I will try that when the "protection board" comes


2 years ago

There are quite a few decent multicell chargers/balancers on the market , just go to amazon or hobbyking or something and look around for "LiPo charger" look for ones that can charge at least up to 4S (4 Series cells) and you want one that can deliver up to 6A if you have proper 6000mAH batteries.

The purpose of the ballence lead is to keep the voltage on all the cells the same throughout the charging process.

HOWEVER, something gives me the sneaking suspicion that your 6000mAH batteries are FAKE. The top notch best quality 18650 batteries are 3100mAH, and there are a lot of chinese con sellers rebranding old recycled laptop batteries, which are generally not even 1600mAH as 'ultrafire', 'trustfire,' 'spiderfire,' 'etc etc etc. Basicly any 18650 battery that claims to have more than 3200mAH is almost certainly a fake, old, recycled battery that might not even hold a charge.

That's what I was thinking too...

eBay is very notorious for selling fake lithium ions.

+1 +1 Totally agree

There is often a significant difference in weight - a real 18650 should weigh 45 grams or more. and have cost you anywhere from $10 to $30. Almost without doubt the cheaper offerings are smaller batteries in a 18650 case.

Sometimes a small as 800 mAh. It is almost certain that despite what the case may tell you they don't have under and over volts protection either..


A commercial lipo charger will protect the batteries from over charge and potential fire. So that is by far the best way to go. To maintain correct voltages on all cells they should be charged with a charger that has a balance plug, this allows the charger to charge/discharge individual cells to make sure they all have the same voltage.

Go comercial - a lipo fire isn't funny.