Size of charger

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Size of charger

Postby Carolina » Sat Dec 12, 2009 5:11 pm

Having 6 ea 6 volt gc batleries, what size alternator would you recommend for a reasonable time for recharge if batteries are less than 50% depleted. Total amp hours in bank are 600 amps.
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Re: Size of charger

Postby elnav » Sun Dec 13, 2009 8:38 am

what size capacity of battery do you have? Rule of thumb is max bulk charge rate is 25% of amp hour capacity so if you have 400 amp hours you can charge at up to 100 amps charge rate
Arild Jensen
Custom electrical design for cruising boats
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Re: Size of charger

Postby Capt Alfex » Mon Dec 13, 2010 2:05 am

6 GC batteries hooked up as 12 Volts = 3 x 200 Ah = 600 Ah. Assuming you never discharge them below 50%, would leave you with 300 Ah to charge back up if you discharge them down to the 50% level.

A 40 Amp alternator (normal OEM) would take about 8 hours to charge up your batteries. A 100 Amp charger would take about 4 hours to charge up. So it depends on how long you plan on running your boat between anchorages. A 200 Amp charger would take 2 hours to charge up but requires a lot more money and maybe extra heavy duty mounts on the engine depending on your current installation.
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