NiMH Batteries

This is one of my homemade NiMH battery packs. These deliver 4.5ah at 12volts and power our 10w HID dive lights for over 4-hours.

Two of these packs easily fit in a Dive Rite Wreck Canister for 9-hours of burn time in a very small package.

New "4/3 Fat-A" cells with solder tabs (4500mah at 1.2v each). These cells were ordered from The NiCad Lady.

Stacking the cells together into a 10-pack using a bit of Crazy-Glue to hold them in place. Caution-Insure they are oriented correctly as it's almost impossible to to separate them once glued.

Never solder to batteries without a heat sink. Here you can see me using a hemostat to isolate the soldering heat from the batteries.

Once the pack is at this stage it's time to charge and burn test it. One pack I made was accidentally shorted during assembly (oops..). The good news is a total discharge doesn't hurt NiMH cells but I did need to individually charge each cell up to .8-1.0v before the automatic charger would work correctly.

End plates cut from .060" HDPE

First full charge on the Maha/Radio Shack (p/n 23-250) charger.

Click on the following link for a spreadsheet with detailed burn test data for my first NiMH pack.

Burn Test 1.xls

UPDATE !!!

These packs have performed flawlessly. I'm now a complete convert and have been using NiMH cells (solder-tab and button-top) in a number of different applications with nothing but praise (underwater strobes, digital cameras, etc.).

I receive a lot of e-mail asking where I purchased my cells. Mine came from The NiCad Lady.