Is this okay - or should I go the long route?

My first pack, my first power wall.

Spot welded the positive side with fuses from BatteryHookup. The other side, these Double nickel strips from China. Now for the crossing direction, do I need to weld that strip on for every row, or as Ive done it so far - for each 5 rows?

The AC load will be around 7kwh - powerwall will be 14s188P when all 14 cells are done.

See image -

https://ibb.co/rFbMCCw

Is the load 7kW ?

Or 7kWh over what amount of time?

7kW inverter sound like a strange size inverter. Please clarify what you are going to hook up to the battery pack. If you have done your math before building the battery you should know what you need in terms of hooking the battery up to the system itself

should go another route, like posting in the correct section

Korishan said:

should go another route, like posting in the correct section

Click to expand...

Hah. I was looking for another section, which one was right?

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daromer said:

Is the load 7kW ?

Or 7kWh over what amount of time?

7kW inverter sound like a strange size inverter. Please clarify what you are going to hook up to the battery pack. If you have done your math before building the battery you should know what you need in terms of hooking the battery up to the system itself

Click to expand...

I have not decided inverter size yet. The house will maximum pull 7kwh at the same time.

We have calculated on busbars many times, but Im unsure how to calculate how many nickel strips in the other direction.

If its max at a time then its kW not kWh.. Kwh is power over time...

7kW is HUGE load!

7Kw with losses would at the battery side be around: 8.4kw in worst case.

8.4kW at 46 volt (minimum voltage of a 14s) is 182A.

Thats 1 A per cell in best scenario. In the worst thats up to 1.5A per cell. I hope you have tested your cells properly?!

Doing 180A towards pack then you need some heavy dury wire and contacts and the busbar need to be able to carry this current with as low resistance as possible.

You should run a HEAVY duty copper wire all the way from one end to the other to support this current. I would say around 30mm2 or heavier even. That nickelstrip is not enough to carry that current alone at all if you connect the pack at one end. You need to distribute it in a good way

As example on my packs that are made to do MAX 80A i have 15mm2 wire in total.

M1kkel said:

Korishan said:

should go another route, like posting in the correct section

Click to expand...

Hah. I was looking for another section, which one was right?

Click to expand...

The one it's in now It's about battery pack design/build.

+1 OP you need some copper for those currents.
You could add a "harness" with eg say 6 or 8 smaller 6mm2 cables to join at points distributed over the busbars.