_ said:Ian Smith said:I've put them on a machine which charges fully (500mA to a 4mV -ve
delta-V, then a top-off at 100mA), waits 10 minutes then discharges at
500mA to 0.8V, waits ten minutes then repeats the cycle twice. I then
average the discharge capacity from the three cycles. So, that's a
moderate load current, but nothing too extreme, to quite a low voltage
(in a battery, I generally aim to stop at 0.9V per cell).More details on this machine, please.
It's a battery charger as sold to electric RC types. Personally, I
use a Triton. http://www.electrifly.com/chargers/gpmm3153.html has
the latest model.
Mine does 1-24 NimH or NiCd cells, 1-4 Lithium cells, 3/6/12 lead-acid
cells, adjustable up to 5A charge, adjustable up to 3A discharge,
various charge termination criteria, various programs, up to 10 cycles
of any program.
Triton very cheap for the spec when it first came out. The
switches are a bit flaky / tacky and I note that the latest version
they've uprated them.
A little upmarket from the Triton is the Robbe Infinity 2, and better
still the Infinity 3 (http://www.robbe.de but you're on your own from
there on because their web site is hard work). This is what I wanted,
but at the time of purchase budget didn't stretch to it. The Infinity
2 and 3 can do 30 cells, at higher currents. (The second output, btw,
is a waste of space - it's equivalent to a 4 quid wall-wart.) If I
were buying now, I'd probably buy an Infinity 3.
All the above run off a 12V DV supply, but it needs a decent current -
these chargers will step up the voltage if required, so are pulling
higher than charge currents from the supply. I use a home-modified
surplus PC supply (you need to provide a power-good signal back to the
supply, and draw a decent current from the 5V lines to get the 12V
stable on a PC switched-mode supply).
http://www.rcbatteryclinic.com/ has some good stuff about this sort
of charger, and has reviews of the Triton and the Infinity 2, though
in both cases older than current models.
regards, Ian SMith
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