John Lussmyer via EV wrote:
I have a couple of old electric forklifts that I use occaisionally in my shop.
One is a little walk behind unit that uses 2, 6V golf cart batteres.
The other is a full size forklift that has a 36V, 750AH battery.
I need to replace these batteries. I don't like Lead-acid batteries for these
machines, as they often sit unused
for months.
I would think that lithiums would be an expensive option; far more than
lead-acids. I'd also be concerned about the cost of lithium cells with a
high enough peak current capability. These lifts usually draw hundreds
of amps.
The cheapest route is probably to buy a used industrial lead-acid
battery that's too weak for the original customer; but good enough for
your light usage. The key of course is to find one that hasn't been left
sitting around dead for so long that it's useless. When not abused,
these batteries can last for 10-20 years.
For lead-acids, you might also want to look for some surplus cylindrical
Gates/GE/Hawker/Enersys gel cells. I have some of the earliest Gates
2.5ah "D" size cells that are now nearly 20 years old, and still have
half their original capacity. They can deliver very high currents, don't
seem to mind sitting dead for months, and have a very long life. A
drawback is relatively low cycle life (like 200-500 cycles), and the
need for *careful* charging (destroyed by overvoltage).
Another thought... didn't you have a set of aircraft nicads? They should
be idea for this kind of application. Very long life, don't mind sitting
dead when not needed, and good for very high currents.
--
Obsolete (Ob-so-LETE). Adjective. 1. Something that is simple,
reliable, straightforward, readily available, easy to use, and
affordable. 2. Not what the salesman wants you to buy.
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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