Re: [A/S] battery question

[Jim Dunmyer <jdunmyer@xxxxxxxxxxx>]

Scott,
 You should disconnect the original battery when you add capacity.
Paralled batteries will tend to have the higher-voltage one(s) charge
the lower-voltage units. You could use a diode isolator, but I'm not
sure if it's worth it.

Your trailer batteries WILL charge off the tow vehicle if everything's
wired properly, but you'll be sadly disappointed in the rate of charge.
My own measurements show a charge rate of about 3-5 amps, which means
it'll take FOREVER to charge a low battery on your trailer. The only way
to overcome this is to use very heavy wire between the tow vehicle and
trailer, something on the order of #4 welding cable, with appropiate
connectors. The problem is that the very slight voltage drop from the
normal #10 wire causes the vehicle's alternator regulator to think that
the battery is fully charged (in essence, it senses only the vehicle
battery), so cuts the charge rate.

Standard voltage converters aren't much better. They charge a low
battery at a low rate, typically 5 amps or so, and overcharge a 'full'
battery, causing it to use quite a bit of water. The best solution that
I see is either a StatPower charger or Intellipower converter with the
SmartCharge module. The former is a bit under $200.00 from StatPower's
web site, the latter is about $250.00 from Camping World.

                                          <<Jim>>