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dfraizer avatar image
dfraizer asked

Adding 2X lithium batteries separate AGM start battery, what do I do with the thruster and windlass

I am converting to lithium batteries and will continue to use an agm deep cycle start battery. Should I draw off the start battery with the thruster and windlass. It is 100 amps

Lithium Battery
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5 Answers
Paul B avatar image
Paul B answered ·

you would have to spec out the batteries MAX current draws from the devices and then make your choice, were you placed the load

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oceanwolfe avatar image
oceanwolfe answered ·

Why would you want to use the starting battery? Have you changed the voltage for the new Li house bank?

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dfraizer avatar image
dfraizer answered ·

Yes, I am significantly upping the capacity of the LI batteries. My only thought would be that the engine will most likely be running with a high capacity alternator when the windlass/thruster is being used. I also read??? that Victron does not like those kids of loads running off of LI?

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tony-c avatar image
tony-c answered ·

I realise this is not your question, but. You say you have a high capacity alternator, have you considered what to do when the lithium become fully charged but the engine (iron sail) is still running? The battery BMS is going to stop incoming charge and that is not going to make the alternator happy at all.

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dfraizer avatar image
dfraizer answered ·

I agree that the BMS Cl 12-100 will stop the charge on the Lithium’s, but what is the issue with the AGM deep cycle. It would be know different than if I had a single start battery without a service bank and the regulator stepped down to float mode. Am I missing something?

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