Battery trip

After a day with little or no solar input (and hence batteries flat with 4% SOC at around 2.00am this morning as expected) the sun returned today at dawn and started to charge the batteries.

However, around 11.30am, at about 41% SOC the batteries reported high voltage, then "Bus over voltage" and stopped charging. I saw over 58V reported as battery voltage at that point, it had risen by 4V from the last 5 minute reporting slot. When I looked at them, one was normal, the other had a flashing green light, and fewer lights lit than the first (master). The app reported 0% SOC and no charging. In time honoured fashion, I shut them both off, switched off the DC isolator to the AC3.0, then turned that off as well.
AFter a minute or so, I rebooted the system - both batteries came on as normal, with no flashing leds. After a minute or so, the system started to charge them, and seems to have continued to do so (now at 60%SOC), with one short term glitch when the charging stopped then started again,

I also note that, on the portal, if I select "settings" on the inverter card, and then "Battery options", the max charge and discharge rate sliders are showing a maximum of 256W, although they are charging at 2900W right now.

Any ideas what went on? Could this be a loose wire issue?

Same thing today - "bus overvoltage " reported, DC isolator tripped.

Reset everything - back in operation.

Check the connections on the dc isolator - might be the usual culprit of pinched insulation in the terminals. Bottom seems to be favourite.

But unless you are confident don’t do it. And if you do make sure everything is turned off. Batteries included

We had this error several time getting worse and worse, the installers came out several time and tightened the connections, the last time they replaced the switch unit and it’s been OK since then.

Funny - I was beginning to suspect the connections needed tightening on the isolator, as I am pretty sure any heat generated there can lead to tripping.
Would be an easy job for me, but I can't touch it as still under warranty.

wilfleek I did mine a few days after it was installed. I told the installer and he was grateful he hadn’t got to get his guys back to do it.
Anyway. How would they know?

You might say that, I couldn't possibly comment................... 😆

Thermal imaging camera confirmed heat from a loose connection (very loose, now tight!) in the DC isolator, allegedly.

I would post that pic but don't have it on a hosting site to link to.