On Feb 16, 3:18*am, "PrecisionmachinisT"
wrote:
"Winston" wrote in message
...
Refer to Clue above. *I suspect that the charging circuit is
heavily current - limited and would not supply sufficient
current into the very low impedance of a properly sized battery
to cause harm.

DC circuits have zero impedance
....

DC circuits eventually settle to voltage and current values determined
by resistance, regardless of their reactance which can be
considerable. Impedance is the combination of resistance and
reactance, as Rich wrote. For 12V lead-acids the temporary surface
charge of about a volt also affects the charging current.
http://batteryuniversity.com/learn/a...d_acid_battery

When testing the "45W" HF solar panels I found a bad Hawker Cyclone
that I hadn't been charging as the article recommends.

BTW the solar panel rating is misleading, They produced nearly their
rated current but the rated voltage to get 45W is 17.5V which they may
well reach but not when directly connected to a 12V battery as with
the included controller. I saw 32W, still not bad for February in NH.
The local store had them at $159 and I got some more off for taking a
crushed box. They tested OK for open voltage and shorted current in
the parking lot.

I bought a bunch of the cheap HF multimeters for battery and auto
work. The 10A range is good enough to check small-engine charging
currents and if I fry one I'm out only $3 - $5. I checked two against
good lab voltmeters last night and found they were about 5 counts off,
50mV at 10V, which doesn't really matter for 12V lead-acids.

jsw