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Battery Bank Connections - What's Best?

I have seen diagrams that show lithium battery banks connected in all three ways shown below. For my install, Option 1 would be easiest.

Are there any meaningful differences between these three methods that make 2 or 3 the preferred choice?


Lithium Batteryinstallationcable
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2 Answers
jeroend avatar image
jeroend answered ·

Option 1 (and 3 as they are the same) will cause battery in-balance issues as the battery closest to the Multiplus will be used the most and the one the longest distance away the least. This happens because the resistance of the cable is higher when the cable is longer. (also the reason for so-called 'voltage-drop' when using too thin cables and therefore higher resistance)

I would say option 2 is almost correct; the cable from Multiplus to last battery terminal should be equal comparing negative cable and positive cable length.

So the cable between Multiplus and first negative terminal (of the top battery) in option 2 drawing should be the same length as the cable between Multiplus and first positive terminal (of the lowest battery) in option 2 drawing.

See also https://www.victronenergy.com/blog/2019/09/03/wiring-unlimited/

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marekp avatar image
marekp answered ·

Option 2 is correct.

I see no difference between Options 1 and 3.

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