Simple question on protected Li-Ion cells.

[painless]

Can individually protected AW 18650 cells be used together(18650x2 or AW-C x 2)? Will I burn something up or ruin the cells in short order?

I read some where that it should not be done, yet have been told by several others that it can be done with out malfunction.

 

[starburst]

I'm using 2 AW's C cell's in Rop mod without any problem's.

 

[mdocod]

they will be fine, just don't charge them in series. Li-Ion can be charged as single cells, in parallel, or in balance controlled packs, but should not be charged in series repeatedly. (they will get out of balance, one of the cells will likely suffer premature wear as a result).

 

[painless]

Thank you.

 

[darkzero]

they will be fine, just don't charge them in series. Li-Ion can be charged as single cells, in parallel, or in balance controlled packs, but should not be charged in series repeatedly. (they will get out of balance, one of the cells will likely suffer premature wear as a result).

I've read that Li-Ions can be charged in parallel but I don't understand. Does this only go for protected cells? Say if you were charging unprotected cells in parallel & one of the cells fully charges before the other one does. What happens? Won't the charged cell then overcharge?

 

[Greg G]

Can individually protected AW 18650 cells be used together(18650x2 or AW-C x 2)? Will I burn something up or ruin the cells in short order?

I have several lights that I run AW's protected cells in. 18650's and C's. I always use batteries that have the same amount of "charge" in them. In other words, I charge them all at the same time so that each battery has the same amount of juice in it. I don't mix cells with varying amounts of power in a light.

 

[SilverFox]

Hello Darkzero,

When you hook up Li-Ion cells in parallel, one cell can not charge faster then the other cell. The voltage represents the state of charge, and in a parallel set up the voltage of each cell will be the same.

Tom

 

[Fallingwater]

Just be careful to only connect in parallel cells that have more or less the same voltage (i.e. charge status). If you parallel a charged cell and an empty one, the empty one will suck as much energy as it can from the charged one, and this can cause significant damage if the protection doesn't kick in.

 

[SilverFox]

Hello Fallingwater,

While it is usually not much of a problem with single cells, the voltage differenc can become an issue with battery packs.

The general recommendation is to make sure your cells are within 0.5 volts (open circuit, resting) of each other before hooking them up in parallel.

Tom