12V Ni-Cd battery pack from Cygolite QUESTION, help please

Hi guys,

As the title eludes to:

I have a 3.0 Ah - 12V Ni-Cd battery pack from Cygolite which powers my zForce HID bicycle light. See http://www.cygolite.com/

It came with a charger that outputs 12V DC @ 750mA (it is a slow overnight charger, the instructions say it takes 11 hours to charge the 3.0Ah battery)

Currently being mailed to me is a Multi-current Universal fast smart charger (6-10 cells) to charge this battery pack more appropriately and faster.
http://candlepowerforums.com/vb/showthread.php?t=104771&page=1

My question is:
Does any one know the make up of this battery pack (it's glued shut).
One might think it's 10 x 1.2V cells, but wouldn't it actually be 9 cells so 12V charges it more appropriately??

Can any one help?
I have e-mailed Cygolite with no response, so far.

Regards
Dave

I received a reply from customer service @ Cygolite.

They state it is a 10 cell pack.

Their tech guy is away at the moment but he will be contacting me shortly to confirm and I'll be getting (hopefully) some more info about the acceptable input voltage range so I might be able to build a Li-ion pack in the future.

I was also told that the battery pack is "sealed shut and cannot be opened", so it's not serviceable.

I was also warned against using any battery or charger that is not from Cygolite as they stated they did not know how the headlight would react to use with non-Cygolite parts.
(my warranty expired a long time ago)....

For everybody's info (if anyone's interested).

Regards
Dave

IF the 12V charger is a wall wart type charger, and although it is Marked 12V, and outputs around 12V under a high load, it can get as high as 15V at a very minimal load.
so unless its a "switching" or "regulated" type power supply the voltage varies quite a bit.

only way to see that for sure, is to measure the thing with even a cheap meter.

that type of power supply works out just fine for charging that thing.
it will automagically slow down at the end of charge, its dumb slow and that method has worked for Ages.

if you used a different charger, especially a fast charger or smart charger, it would use a different principal for stopping the charge.
if you used a meter, you could figure out how many ni-cd cells are in the pack.

meters are cheap and your gonna need one if you change things around anyways.

Thanks for that info.
I really appreciate it.

Regards
Dave