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drb asked

Can’t find information on outboard charging

I have an Orion12-12-18 dc to dc isolated charger. I want to charge a 100 AH Lithium battery through my 65 AH agm battery. The outboard on my sailboat is a Tohatsu 6 hp. It has a rectifier/regulator that puts out a maximum of 5 amps at full throttle. Is it possible to charge with a current this small? If it is possible, can someone please explain why it is necessary to use such heavy cables and large fuses on the input and output side of the charger as recommended by Victron. The output wire from the motor’s regulator appears to be only about 14 gauge. The run from the motor to the battery is only about 4’.
Please help me make sense of all this as I am a nubie!


orion dc-dc
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1 Answer
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kevgermany answered ·

The recommended cable sizes for the Orion assume a powerful source that can drive it at full power. In your case that's around 19 Amps.

Rule of thumb for alternator loads is that continuous load should not be more than 50% of its rating.

Your intended setup will pull full Orion current from the AGM battery, alternator will try to service this at full power, won't match it and will probably burn out. The AGM battery will end up under charged and wrecked.

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