On Tue, 8 Jul 2014 18:06:29 +0100, "Ian Field"
wrote:

AFAIK - Ni-Cd cells like to be fully discharged every once in a while - but
not in a battery of series cells.

It's not just NiCd batteries, but all batteries. The RC (radio
control) crowd had an ususual opportunity when they started building
their own battery packs and found that charging them in series was a
guaranteed disaster. So, they came up with the "balance" charger
which charges each cell individually. All (and I do mean all) RC
battery packs include seperate connectors for charging and
discharging. I have a fancy balance charger, that will do many things
that ordinary series chargers won't or can't do (if I can decode the
Chinese instructions).

https://www.google.com/#q=balance+charger
https://www.google.com/search?q=balance+charger&tbm=isch

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558