question

kurt404 avatar image

Can I remove 4 batteries from this setup?

I have 2 batteries on each of my 2 Cummins engines at 12 volts and 4 batteries for my bow thruster at 24 volts. Can I eliminate the 4 engine batteries and tie them into my thruster batteries assuming the bow thruster is not on a common ground? See Pic

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3 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

No because the engines will both be grounded to a common point. That means the left pair of thruster batteries would be shorted out through this common ground path.

How much power does your bow thruster take? Would it be possible to take 12 volts from the starter batteries and run it through a 12 volt to 24 volt converter? You can get 24volts at 20 amps (480 watts) out of a Victron Orion 12/24-20. Two of these could be paralleled each running of a pair of starter batteries. The converter output is not isolated from the input but that shouldn't be an issue in this application since you said the bow thruster is isolated from engine grounds.

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kurt404 avatar image
kurt404 answered ·

And I am between 350-450 amps on the thruster.

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kurt404 avatar image
kurt404 answered ·

I see that now. I was focused on putting it all in graphics and missed it. I knew I couldn't before but changed my mind when it all looked pretty on paper. A Volvo's diesel 24v system uses only 4 batteries for all and I was looking for a way to do a similar setup with my Cummins. I currently have 4 lithium batteries for my house (boat) and purchased 4 more for the engines. Now I am second guessing if lithiums are good for a starter battery.

This is my current setup:





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