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Old 24-08-2010, 22:31   #1
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I have [2] 6 volt deep cycle interstate batteries which are wired to get 12 volts, my rv inverter puts out 65 watts or 5.4 amps can I add my gas generator which has a 7.5 amp 12 volt built in charger to the 65 watt rv inverter to speed up my charging. I will only be adding the generator when my batteries are low and not for long periods of time maybe two hours or less, can I do this yes or no please help.

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Old 25-08-2010, 05:15   #2
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An inverter draws current. It doesn't charge anything. It may be rated for 65 watts but that means it can run something with that power demand from the inverter (which in turn draws from the batteries).

Your gas generator 12v output will not charge anything - you need a higher voltage than 12V to charge batteries - typically 13+volts.

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Old 25-08-2010, 06:47   #3
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Assuming your inverter is a charger/inverter I wouldn't try to run the generator at the same as would be 2 different AC sources and wouldn't be in phase (and shore power it going win that war over your generator). Also if it is a charger/inverter it wouldn't make any difference on output to the batteries adding more AC into it as it still would have same output.
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Old 25-08-2010, 07:16   #4
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Usually charging from two underpowered chargers simultaneously buys nothing.

The reason is the rate of charge depends heavily on the battery's terminal voltage

Charging currents = (Vcharger - Vbattery)/(total resistance)

where total resistance includes that of both the charging source's internal impedance plus all DC resistance plus the batteries internal resistances.

NOte that as the battery voltage increases, the charging current decreases.
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Old 25-08-2010, 08:45   #5
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two charging sources will deliver charge current during the bulk phase when the batteries are low, during absorbption phase the smarter the charger the more current it will deliver. If your mains battery charger is intelligent it will do the majority of the absorbtion phase charging
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Old 25-08-2010, 08:52   #6
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Technology Review: A Blended Battery Pack for Cars

A little about this kinda thing here too. If your looking for ideas.

It's faster horses, younger women, older whiskey, and more money!
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