Battery charger size

[Claude Labrecque]

We have a Legend 35.5 with 440 amps house bank (4 group 31 flooded type batteries) plus an independent starting battery. Our boat is equipped with 12V Adler Barbour Refrigeration system. We want to change our actual Ferro resonant Newmar battery charger for a new multiple stage electronic unit. Our choice is to go with Statpower TrueCharge 40.However, the breaker on my dock outlet and my shore power cord are both rated for 30 amps.Will my new charger ever get a chance to charge at full power of 40 amps?Should I buy a TrueCharger 20 instead?We use our boat on weekend and leave the boat connected with shore power cord from Monday to Friday. On a typical week, we are unplugged from the dock for about 50 continuous hours and connected the rest of the time. Thanks for any suggestions and comments!

 

[Ralph Johnstone]

You Should be Just Fine ....................

... as you will only be drawing 4 amps at 120 volts from your shore power as shown by the formula:power in = power out120V x 4A = 12V x 40A480 watts = 480 wattsRegards,s/v Island Hunter

 

[Tim Schaaf]

Actually, the draw is a bit more....

since the "power factor" on the Statpower chargers is about 1.7, which I learned about the hard way, sizing a small gas generator. So, your draw will actually be about 7 amps. Either way, you are in good shape.

 

[Barrie McDonald]

Battery Chargers

Claude,On my Hunter Legend 37 I have a 3 stage 45 amp charger that draws only 4.5 amps and can recharge my 4 deep cycle 6 volt golf cart batteries wired in series in a few hours. These are my house batteries.I have a seperate 10 amp charger that charges my 8 evd starter battery that also receives charging from my engine alternator. Works real well. With both chargers on together I draw about 6 amps or so. No big deal.Barrie

 

[Claude Labrecque]

Many thanks for all your knowledge!

This forun is very informative... thanks again.