Charging multiple 18650 cells off a RC charger

[CutieSquiggoth]

Hello.

I'm setting up a light system for my trike, and for now I'm going to strap some flashlights to it as that will get me started cheaply enough and still do a good enough job.

I'm going to have to recharge these flashlight batteries though. I'll have about 5 batteries to charge each time, maybe a few more and I'm wondering what the best way to do this is.

The batteries are 18650 LiON (what is the correct case for that?)

I'm hearing that an RC charger connected to a cradle of some sort is good, and my eventual light set up (if this one somehow isn't good enough) will be powered off RC battery packs so that is probably the way for me to go.

What can people suggest?

 

[hellokitty[hk]]

If they're around the same voltage, you can just find or make a cradle that will parallel charge them. Else you'll probably need to charge them individually, at least until they're at the same level of charge.

 

[Stephen Wallace]

Another alternative would be to purchase a balancing harness to use with the hobby charger and wire that to whatever type of cradle you end up using with it.

The other option is to use a consumer style, automatic cradle charger that has enough bays for all your batteries - the Xtar WP6-II, with six bays, springs to mind.

 

[moderator007]

If the batteries are in parallel they will work fine. They will act as one big 18650, the packs capacity will be the sum of all batteries in the pack at 4.2v. Nothing special has to be done for this to charger or discharge. The possible current output will be the sum of all batteries in the pack added up. If one battery will handle 3amps and has a capacity of 2500mah. Then a parallel pack of 3 will give you a 9amp capable pack with a capacity of 7500mah at 4.2v.
If the batteries are in series then you will have to wire in a balancing circuit to the pack and have leads out of the pack for the hobby charger to connect to. This is a must have feature to keep the series batteries in the pack closely balanced. The voltage of the pack will be the sum of all the batteries connected in series. 4 series conected batteries will give 4.2v x 4 = 16.8v fresh off the charger. But the capacity of the pack will be the capacity of one single battery in the pack. If one battery will handle 3amps and has a capacity 2500mah. A 3 pack in series would give 12.6v at 2500mah with a current capability of 3 amps. And don't forget they must be balanced.

 

[Lightfoot98]

I parallel charge up to 12 cells at a time sometimes.

Different capacities also at the same time. (2600, 2900, 1800, does not matter))

No hassle with charge balance cable setups.

Automatic balance in parallel charge configuration.

If within .5v difference for cells, no problem parallel charging.

I use a TRITON II with home-made parallel charge cradles.