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RE: N.O.S. Wheelhorse
- Subject: RE: N.O.S. Wheelhorse
- From: roden ald net
- Date: Tue, 8 Dec 1998 00:33:51 -0500
- In-reply-to: <2BDEF8A3E55BD211A3CB00805FD6299503B21E@cheste1bdc1.mkg.com>
- Sender: owner-elec-trak cosmos5 phy tufts edu
"Pestka, Dennis J" <Dennis Pestka mkg com> wrote:
> I may still look for a battery upgrade although for
> greater range. I'm hearing a lot about Optimas. They are supposedly
> maintenance free.
Well, they don't need watering. But they're not exactly maintenance
free. You still have to check the terminals and test them now and
If you use any "maintenance free" (sealed, or more accurately, valve
regulated) battery you will need to replace or modify the ET charger. It
is designed to charge flooded batteries which can gas freely at the end
of charge. Its finish rate is much too high for valve regulated batteries.
Valve-regulated batteries have a catalyst and operate under pressure to
re-combine the hydrogen and oxygen evolved at the end of charge into
water. If you push too much current into them during the last 20% of
the charge, you can overwhelm the catalyst. This will cause too much
pressure, so the battery must vent (the "valve regulated" part comes
into play here) so it doesn't explode. Then you lose the water. Do this
enough times, and the battery dries out. There's no way to replenish
it, so at that point the battery is junk.
Optimas are beautiful batteries. However, they require special care in
charging. They are at their best in extremely high-current (600 amps
and up) applications like high-performance on-road electric vehicles.
And they are very costly (about *triple* the cost of a golf car battery).
All other things being equal, range is roughly proportional to pounds of
lead. So, because they are smaller and have less lead, you will
actually have *less* mowing capacity with 6 Optimas than with 6 golf
There may be situations where valve-regulated batteries are appropriate
-- for example, where you know the user won't water the batteries
regularly. For such cases, there are less expensive (and larger) VR
batteries available than the Optimas. In most cases, conventional
flooded golf car batteries are by far the most economical choice for this
David Roden THE VIRTUAL PD
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