Lithium Battery Wiring Diagram

[Rich-MLsRV]

Folks,

I am converting from lead acid to lithium batteries. Attached is how I plan to wire in the Lithium batteries. Let me know if you have recommendations as to what I should change.

thanks

 

[Gronk]

Pulling power from the batteries the way your diagram is is the correct way. That helps ensure both batteries share the load. I cannot see ant issue with your plan.

 

[Rich-MLsRV]

Pulling power from the batteries the way your diagram is is the correct way. That helps ensure both batteries share the load. I cannot see ant issue with your plan.

Good to point out balancing current flow out of the batteries. Subtle important point to make. Thanks for commenting on this.

 

[Kevin D Pem]

Quick question. Do the 3/0 cables go thru any walls that may have metal? If so a fuse on the battery side is in order.

 

[Rich-MLsRV]

Quick question. Do the 3/0 cables go thru any walls that may have metal? If so a fuse on the battery side is in order.

Any changes I am making do not pass thru metal walls. It's all contained within the enclosed battery bay. Thinking about it, a fuse would be a good idea. I'll add a 300A fuse between the batteries and the disconnect switch.

 

[Gronk]

Excellent idea!

 

[Kevin D Pem]

My guess is you will have the terminals covered as well. Lithium is kind of a dangerous capacitor. A wrench welded between terminals would produce quite a fireworks display. Ttat is the kind you run to the closest phone and call 911.

 

[jmltech]

You may want to look at the cables between the batteries and your house connection. AM Solar shows 4/0 cable:

AM Solar 300Ah x 2

 

[Rich-MLsRV]

You may want to look at the cables between the batteries and your house connection. AM Solar shows 4/0 cable:

AM Solar 300Ah x 2

Thanks for the recommendation. Looking at the current carrying capacity of 3/0 and 4/0 ga wire

it makes sense to go w/ 4/0 ga wire. It's interesting how the current carrying capacity is so dependent on temperature. I am not expecting wire temp to reach 140F. If this is the case then something is very wrong.

 

[Kevin D Pem]

The very wrong happens in raceways. I would not worry about 3/0 cable unless your running the inverter at capacity for long periods. You could grab your IR thermometer and see how hot the wires are getting. As an incite the rating on wire is mostly because of the insulation not the copper capacity. Short runs will not see much of a voltage drop so should not make problems with the inverter operation.