So for those wondering if I'm still messing with NEC Versa stuff, yes I am. And I've got a new one....

So I have an original Ultralite Versa battery from 1993 - p/n OP-570-4001 - 3400 mAH, 7.2v, NiMH. I also happen to have a working V/50 and 40EC that work with this thing.

Anyway, after months of it vegging out in my V/50 and assumed dead. I decided to throw it on my McGyver'd together Battery Rejuvination rig.

What is this? It consists of a disused Skill NiCAD charger from a cordless drill I no longer have, 2 galvanized wood screws, and some copper, insulated, 2mm thick wire wrapped around. them that I just drop on the battery contacts like the tone arm of a record player to rejuvinate/charge/break dendrite shorts.

Now I've tried some other methods, I burned out the 40EC's power board (Which I fixed) with a previous method involving a Toshiba laptop charger and some alligator clips by overcharging the battery to 14vdc, and also the higher amperage I think caused some cells to blow under load.

With this method, the Skill charger is far more gentle. It only puts out around 20vdc and maybe 2 amps or less vs the 5 amps of the power supply for the Toshiba at 24vdc.

WHAT I DO TO FIX NiMH Batteries on the Versa (what I've Got Down So Far)

1.) I test the voltages on the battery to see if there is a charge, if the voltage is 3vdc+, I drain it with an old Tape Deck motor to 1vdc or less - both - contacts used.

2.) Once the battery is fully drained, I use my VOM on continunity test to see if there are any shorts, if there are, I put the battery on the Skill Charger to charge, if not, I Try the laptop itself first

3.) The Skill Charger will let me know when the dendrite shorts are gone because the LED light will get brighter as it starts to properly charge, up to full brightness when properly charging

4.) I charge the battery up into the 7-8vdc range, testing both negative terminals to make sure they are the same or within 10% close, then I toss it in the laptop and run the laptop till the battery dies.

5.) Let the laptop charge the battery, and continue the cycle to increase life.

I ran the V/50 off a single charge last night for 30 minutes, kind of amazing for a 27 year old laptop battery with the original cells installed. I'm going to experiment some more to see if I can increase the life span by draining it and then doing a full recharge using the V/50 or 40EC, and then drain down, using the laptop, and then the motor to finish it off.

Eventually I'm building a full rig around this that will make working with the batteries far less precarious.