Battery problems

I have recently started having issues with my battery, notably when charging overnight (when we have a cheaper tariff set up). It appears that at around the same time each night, about 30 minutes in to the charging window (around 3am) the battery is starting to trip the breaker to the inverter, cutting it off. I'm now finding that i'm waking up to see 0% battery on the app, but then resetting the breaker the SOC shows back up and it acts as normal again.

This was happening every so often after we had our smart meter replaced with a SMETS2 (not sure if relevant or having an impact), however it has now started doing it almost every night, and even this afternoon as I tried to charge before the expensive tariff window starts it has tripped again.

Could this be something with the circuit, or do i have a bigger issue with my battery? If the latter then hopefully i can get this fixed under warranty (installation less than 2 years old) if GivEnergy can respond to my emails.

twynefever If this is the DC breaker between the inverter and the battery it could be connection screws that are not fully tight. See if you can tighten the screws that hold the cables into the breaker. There will be 4, two at the top and two at the bottom. Best to do this with the battery and inverter shutdown.

What may be happening is that the breaker is getting too warm over time and tripping out at a lower current than it is supposed to. I had this problem and tightening up the screws cured it for me.

If you don't feel confident to do this yourself, try asking your installer or indeed any electrician.

If they are tight you could have a faulty breaker but you will need your installer to diagnose that properly.

Windy Miller Sounds spot on really, especially as its happening overnight when the metal contracts.

I think I'd recommend a bit of loctite 243 (medium strength) on the screws you mentioned for anyone doing this, just to save you doing it again.

Many thanks for your replies. I’ll give this a go today and see if it solves the problem.
Looking back at the data it does appear to have been when it’s particularly cold that it has been tripping, so makes a lot of sense.

Windy Miller I've had two of these breakers replaced over the last 18 months. I first contacted GE who asked me to contact installer. They changed the switch each time and there was no attempt to charge. Problem was waiting a week for the installer find the 30 min to do the job. I managed to keep going in the meantime by reducing the charging rate which decreased pressure on the switch, which felt warm/hot.

Rob

twynefever Depending on your setup there could be more than 60 Amps flowing for several hours through these connections as the batteries charge and discharge. You would only need a slight increase in resistance from a screw that isn't fully tight to get some significant heating and I believe these breakers work using the heat effect rather than measuring the current (which is more difficult to do with DC than AC) which might explain why it trips at below its rating. As Rbor has noted it runs hot so you could feel it to see how hot it is whilst charging or discharging. And as Vestas has pointed out the cold nights are causing the metal to contract possibly exacerbating things.

Many thanks again for your replies @Windy Miller and @Vestas on this. I did as suggested and isolated the system, took the cover off the breaker and indeed one of the cable was looser than the rest. A quick push in and tighten up then turn back on and the battery charged up fine 2 afternoons in a row. I switched the overnight charging back on last night and woke up this morning to a battery that still had charge, hadn't tripped and appeared all well again.
I can't thank you enough for helping with this. It's probably a minor thing in the grand scheme of how the whole system works, but only if you know that it is.