Cable size for lithium (3 Viewers)

[Marie-Claire]

Hi all , about to order cables to add a second lithium battery, and wondering what size is the best to use. I will have 2 x 100a lithium , each will be connected to its own 50a midi fuse then onto a bus bar where I will feed the inverter from.
Pos Cable length s are
Batt to midi 250mm
Midi to bus bar 400 mm
Neg cable is
500mm bus bar to battery.
Regards
Chris

 

[Jabstatt]

Do you mean 100 amp lithium. In which case, why a 50 amp fuse?

Do you mean 100amp hr lithium?

What size inverter?

What can the batteries deliver, look at the spec.

Tony

 

[Marie-Claire]

They are renogy 100 a capacity, the inverter is a 2000w and the most I have drawn to use it is 80ah split across the 2 batteries. I had both batteries and the inverter in the last van but wired in parallel and not via bus bars

 

[MichaelT]

I used 50mm sq

 

[Jabstatt]

I’m not clear what you have and want.

Enjoy.

Tony

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[Marie-Claire]

I am going to have these made up in either 16mm 110 amp or should I go to 25mm 170amp?
Tia

 

[autorouter]

As Jabstatt says, you need to look up the maximum discharge rate of the battery, in amps, and choose the next highest fuse above that. Some 100Ah lithiums are fine for 100A of discharge, and some can be as low as 50A, it depends on the Battery Management System (BMS electronics that are fitted inside the battery.

Don't confuse the amp-hour charge capacity (Ah) with the maximum discharge flow rate in amps (A). For a lithium the two numbers are sometimes about the same. But for example the maximum discharge amps from a 100Ah lead-acid battery is often only 20A.

A 2000W inverter can in theory draw 166A at 12V, so I would go for the 25mm² wire at least.. The thicker wire would mean less voltage drop too.

 

[Jabstatt]

And remember to consider the TOTAL length, pos and neg.

Tony