JKKM

Yes all Victron equipment.

I can't comment on what the fixes are but can confirm that 1.7 -> 2.1 months back and then to 2.4 recently, 2.1 -> 2.4 and 2.2 -> 2.4 firmware updates were all applied successfully. No issues experienced to date.

Had a similar issue with the sudden increase in "Ambient Temperature" above 90% SOC compared to the rest of my batteries. Firmware update didn't fix the issue. Subsequent BMS replacement also had no effect. Pylontech then replaced the battery.

You can get a zip file with versions for the old (2.8) and new (2.1) chip here -> Lithium storage unit Pylontech US2000C/3000C | Effekta | EFFEKTA Regeltechnik GmbH. I have seen V2.2 for the new chip US3000C Pylontech's but haven't been able to source it.

Information from the battery that was exhibiting the behavior.

The new battery which does not have the issue. 

 

There are no issues adding a new battery. The new battery must be the master battery as described in the Pylontech manual along with how to add it. 

There are no issues adding a new battery. The new battery must be the master battery as described in the Pylontech manual along with how to add it. 

There are no issues adding a new battery. The new battery must be the master battery as described in the Pylontech manual along with how to add it. 

Both the US2000 and US3000 are RJ11. US3000C is RJ45.

You don't need 2 kits. The kit is complete. It has both RJ11 and RJ45 ends. It is much cheaper than the alternative from HD cabling Pylontech Battery Monitoring Cable For US2000, US3000a/b, US3000c, UP2500, UP5000 | Pylontech Console Cable (hdcabling.co.za)

When adding batteries, it is advisable to ensure they are on the same stage of charge %. You might need to charge them individually until they are all at 100% and then add them as a group.