Adding Pylontech UP5000 to existing 2xUS2000B+v2 bank

[1am7h30n3]

I'm adding a Pylontech UP5000 to my existing battery bank of 2xUS2000B+v2. Inverter is Sunsynk 5kW.

This is my plan, please let me know if I've got something wrong:

1. Charge existing battery bank to 100%. Power down everything and disconnect it from inverter.
2. Charge new battery to 100%. Power down everything and disconnect it from inverter.
3. Connect all the batteries in parallel. Positive from inverter to UP5000. Negative from inverter to last US2000B+v2 in bank. Comms cable to inverter goes to UP5000. UP5000 is master and inter battery communication cables daisy chained to each slave through the link ports. Earth wire to screw on each battery.
4. Power everything back up and it all just works.

Is the CAN comms cable pinout between the inverter and the batteries the same, just unplug from the old battery and into the new?

 

[1am7h30n3]

Can confirm comms cable is just a direct plug in swap, works fine.

Step 1 has been completed, existing batteries are at 100% SOC and have been disconnected from the inverter.

Step 2 to charge the new battery to 100% SOC is in progress. I started a little bit late, so I'm not certain that I will be able to hit 100% SOC by tonight, but I'm hopeful. I will run overnight on the new battery alone as a stress test.

Tomorrow I will use solar power to bring the new battery to 100% SOC and when reached, I will disconnect everything and connect the battery bank up in parallel.

It was a bit of a schlep, the 4.8kWh battery is heavy as hell solo, of course then I also couldn't fit 3 batteries into the same location as my existing 2 batteries are stacked, so I have to move everything (this wasn't a surprise, I had measured it beforehand), so that led to significant work and a lot of general cleaning as well... Anyways, overall feeling is positive, project is on track.

Pretty excited to have the peace of mind that this extra battery capacity will give me.

 

[1am7h30n3]

Project is completed.

All batteries wired up in parallel and talking to each other and master to inverter. Nice.

SOH of 2x US2000B+v2 was 95%. SOH of brand new UP5000 is obviously 100%. SOH reported by inverter now is 98%, interesting, so it's averaging from the entire battery bank, I guess I somehow thought it would show 100% of the master battery.