Balance charging

[alan bates]

Hi could some one help and tell me how i balance charge my 2c A123 batteries,there is only one cable a JR discharge plug so i am a little confused?

Many thanks

[Martin Harris - Moderator]

I see 2 possible actions:

a) Add a balance lead to the pack if you are competent.

b) Send the pack back and ask them to supply one fit for purpose!

[Allan Bennett]

A123s are more robust, and tolerant of over-voltage, than LiPos; so many people consider they don't need balancing while charging -- especially if they are "only" 2S.

To balance-charge you'll need 3 leads coming from the battery; one each from the + and - terminals, and the third from the junction between the two cells. If the cells are side-by-side, it should be quite easy to add the third one if you're any good at soldering, for all the ends of the cells will be easily accessible.

Then, you use the original 2 leads when powering your model, but you use all three when balance-charging, if you have the right kind of charger. The simplest way to achieve this is to put all three leads into a new balance plug of the appropriate kind to match your charger, then use a matching socket in your model with only the two outer wires (the + and -) connected.

Alternatively, but more work, you add three new leads with their own dedicated balance plug.

[John Cole]

Posted by Allan Bennett on 28/12/2012 08:46:03:

A123s are more robust, and tolerant of over-voltage, than LiPos; so many people consider they don't need balancing while charging -- especially if they are "only" 2S.

Alan Bates said his were 2C not 2S. I expect they are 3S.

[Allan Bennett]

I assumed he meant "2S" because there's no such thing as an A123 that's rated at only 2C ... unless it's really on its last legs

Many people say "2c", for "2-cell", when they really mean "2S". And because he says it's got a JR discharge plug on it, I suspect it's being used as a receiver battery.

Anyway, alan bates, please clarify that point.