On Jan 16, 9:35pm, "Andrew C. Green" wrote:
> As for recharging the battery, if you're not using the one in the car, I've
> seen solar-powered trickle chargers with a panel that you hang in a window.
> Can't vouch for their quality, however, nor whether they can supply enough
> oomph to do a recharge vs. a maintenance charge. Anyone else know?
For the most part, no. All of the "set on the dash/hang on the window, plug
into the cigarette lighter" solar panels I've seen in "specialty" catalogs are
only capable of putting out 40-50 mA at 13.6V in bright sunlight. This really
isn't even enough for a "maintenance" charge. The minimum acceptable charge
rate for a battery is generally accepted to be a "C/20" rate. That is, the
"Capacity" of the battery in ampre-hours divided by 20. An automobile
starting battery (typically 50 ampre-hours and up) or a marine-type deep cycle
battery (100 ampre-hours or so) should be charged at a 2.5 to 4 ampre rate.
Note that even at this rate it will take about 30 hours of bright sunlight to
recharge a fully discharged battery, which means you'd need 6 hours of bright
sunlight each day for a week if you discharged the battery completely each
weekend. You can get 50W solar panels you'd need for a task like this, and
you should expect to spend about $10/watt for a decent one.
Pat Vilbrandt John Fluke Mfg. Co., Inc. Everett, Washington USA
UUCP: pwv@tc.fluke.COM or: { uunet, uw-beaver, sun, microsoft }!fluke!pwv
ARPA: fluke!pwv@uw-beaver.ARPA
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