[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Battery Chargers, Pulse Units
- Subject: Re: Battery Chargers, Pulse Units
- From: roden ald net
- Date: Sat, 12 Dec 1998 02:49:02 -0500
- Sender: owner-elec-trak cosmos5 phy tufts edu
There are lots of things to consider.
If your batteries are just now getting weak after 8 years, I think that's
pretty good performance. In an on-road EV, we're lucky to get more
than 3 years from a pack.
I really think that the existing ET charger is adequate for flooded golf
car batteries. That 8-10 year service life is actually quite decent.
That said, it is not a very sophisticated unit, and there are more
modern types available.
The Italian company Zivan makes a range of modestly priced 3-stage
chargers in various voltages. They are based on switchmode power
supplies, so they are fully transformer isolated, but are much lighter
than the typical boat-anchor ferroresonant or conventional transformer
The Zivan NG1, available in outputs from 12 to 48 volts, is reportedly a
very well-built unit with the price to match -- $573. It's a 1000 watt
charger (about 27 amps at 36 volts). The older K5 is less robust,
perhaps not as nicely built, with less capacity (15 amps at 36 volts) --
but it's cheaper at $461.
See http://www.mcn.org/a/innEVations/chargers.html for information on
the Zivan chargers.
Ken Olum points out that three 12v chargers are usually cheaper than
one 36v charger. That's true for simple, inexpensive utility chargers,
but not so true for sophisticated 3-stage chargers. (Most 12v chargers
you can buy in a hardware or auto parts dealer for $40 - $75 each are
simple taper chargers.)
One very interesting charger I've heard of is made by Statpower (see
http://www.statpower.com/tc20.htm for one example). It's a true 3-
stage charger that delivers 20 amps (they also have 10 and 40 amp
Each charger is supposed to be able to charge up to three 12v
batteries. It has 3 separate diode-isolated output terminals, though it's
unclear to me whether the charge control actually senses and controls
the batteries separately. Also, all 3 outputs share a common negative,
so you'd have to disconnect your batteries from the tractor's series
string before charging -- a real pain. You would probably want to use
one separate unit for each 12 volts of the tractor's battery string.
I don't have any personal experience with Statpower chargers, but they
look pretty sophisticated.
Statpower has an online store where they sell older refurbished units at
about half price (I suppose one might wonder just what the failure rate
is if they have lots of warranty returns to refurbish). A 20 amp dual-
output charger is priced at Can$215 (US$139), pretty reasonable for
such a unit. The 10 amp refurbished charger, which does not have the
dual output feature, is priced at Can$152 (US$98).
You would probably need three of either unit to charge 36 volts worth of
batteries. If these were not refurbs, three of them would cost more
than a 36 volt Zivan NG1 (but they would do a better job of keeping the
different batteries at an equal state of charge than a single charger for
the whole series string).
There are 3-stage chargers made by Guest Corp. which actually have
three separate chargers in one box. However, I have heard of reliability
problems with these chargers. Too bad.
Sorry that I also have no personal experience with the pulse units. One
person whose judgement I value points out that nearly *every* charger
is a pulse charger, because they all rectify AC and put out pulsating
DC at 120 pulses per second. However, I have heard reports from
other people I respect who say they have had good results from units
like the Canpulse. I get the impression that these units operate
independently of the charger.
If you try one, please let us know how it works for you.
David Roden THE VIRTUAL PD
Services for radio broadcasters targeting educated adults
Programming Air talent development Research Classical music