Different sized cells together?

[donn_]

This may be a silly question, but it wouldn't be my first.

Is there any reason not to run different sized Li-Ion cells together in a light? For example; a 17670 and an rcr123 together in a 9P (with a spacer), or a 17500 and 2x rcr123s?

How about mixing AW C cells and the new Kaidomain 2*D 8.4v pack together in a D-Mag tube with appropriate spacer?

 

[eshishlo]

This is what happens:
http://youtube.com/watch?v=V7m61plCjVE

 

[SilverFox]

Hello Donn,

The problem is that different cells have different capacities. When the lower capacity cell has expended all of its capacity, the larger capacity cell tries to reverse charge it. This runis the lesser capacity cell, at best, and sometimes leads to rapid venting with flame.

I must add that this is for cells in series. If you run them in parallel, there is no problem at all.

:devil: Out of curiosity... Do you happen to remember your first silly question...? Never mind.

I maintain that the only silly question is the one not asked.

Tom

 

[craigberesh]

I would not do it. You risk ruining your equiment as well as personal injury.

 

[donn_]

:devil: Out of curiosity... Do you happen to remember your first silly question...?
Tom

I don't remember, but Mother tells me it was my first question.

I don't think I'll try it.

 

[SilverFox]

Hello Donn,

Same here...

Tom

 

[Fallingwater]

Read this.