In article .com,
wrote:
Hello, I use a 12 volt winch to pull my boat up on a marine railway at
my seasonal cottage in Canada. I do not have permanent AC power to the
location, but can get a big enough extension cord to it if need be. I
want to buy a more powerful winch which requires a battery rated at "12
VDC - 650 Cold Cranking Amps" which is not a problem. I would like to
buy a back-up 12 volt AC to DC converter to power the winch if the
battery fails. Please advise on how to rate the converter based on the
battery requirement. Much thanks! D. MacQueen.


Unfortunately, Cold Cranking Amps is a measure of battery capacity to
store energy, not an indication of how much current it can supply at
any given time. See if you can find an actual current requirement on
the winch, i.e. number of amps.

If not, you would be better off buying an automotive battery
recharger. One that is capable of 'boosting' or starting a vehicle,
would have no problem running a 12V winch. For that matter, if you can
get your car close enough, you could use a good set of jumper cables
from the car battery to power the winch.


--
Contentment makes poor men rich. Discontent makes rich men poor.
--Benjamin Franklin
Larry Wasserman - Baltimore, Maryland -