I own a Fluke DSP-2000, a cat5 network certifier. It's a great little machine, I bought one as I do some networking work on the side and I'd used one at work. It works well, except the people who designed it apparently didn't know a thing about batteries. It takes proprietary NiCad battery backs, BP7217's, which cost about $130. I suspect they consist of 6 AA batteries, they look about the right size, and produce 8.4V, though are marked as 7.2V.

What happens is that if they are left to their own devices, like all rechargeables, they discharge. When they're empty, the fluke refuses to charge them. Since they're proprietary, you can't just put them in a different charger.

So, my question is, how do I trickle charge these myself to get them to the point where the fluke will take over charging? Between myself and work, I've got four dead batteries, so it's about a $500 question. The batteries have five contacts. From left to right, they're labeled -,T,G,C and +. On a good pack, minus and T both read 8.4V differential between C and plus. G is at zero relative to all the other contacts. I don't have a bench power supply, so I'm hoping for something a bit more inventive.

Am I completely wrong in assuming that all these need is a trickle charge to get them started?

Matthew