Re: (ET) NiMH batteries (OT)

[Chris Zach <cz alembic crystel com>]

My experience: I have been using flooded NiCDs for years now, and have 
blown a few Prius prismatic cells sky-high. I have also used Prius cells 
in my Elec-trak (why :-) and on some of the kid's power wheels cars.

The neat thing about these packs are that they are NIMH, and one would 
think "yaay, we can use them with the tractors or cars". The big problem 
is that they are not 60ah battery packs (if so I would be at Harry's 
door with cash in hand :-). They apparently are 60kw peak capacity 
packs, which probably means they are around 6-8ah in size. Based on the 
picture they are too small to be 60ah packs, probably under 10.

NiMH batteries don't parallel-charge very well, if you built a string of 
them you would have to charge each string by itself. Also they don't 
handle being over-charged very well, one person I know blew electrolyte 
all over the roof of his garage one night.

As to getting them working, should be do-able. If I were to get these, I 
would open the packs, charge the batteries and watch them with some 
paktrakrs. Replace any dud cells with spares and make a good pack. But 
then what? I could put it in a Prius or something like that, but it's 
not enough power for a traction car, and one would have to have about 10 
strings in parallel to run them on an Elec-Trak.

Just looked at the specs, it's 288v at 8.5ah. Even the biggest (336v @ 
17ah) would only give an electric car a 20 mile range. And the building 
blocks are the same 8.5ah cells, so it would be a parallel charge system.

Now for me it's back outside to continue wiring up 50 zener regulators 
on a pack for my Prizm. 10 Paktrakrs, 10 temp sensors, 50 regulators, 
and 50 batteries equals a *lot* of work.

Chris