Max battery charge percentage on solar?

I use the "charge to" setting periodically when charging the batteries from the grid, however is it possible to do similar when solar charging please? The reason I ask is that I'm on holiday soon and to prevent the increasingly frequent BMS over voltage alarms I'm seeing, I'd like to set a lower charge level if possible i.e. when charging from solar.

I tend to get the over volatage alarms when the battery voltage sneaks up after a few days of reaching 100% during the day. I'm managing this with some forced discharge but I don't really want to do that whilst on holiday. Any way to stop charging on solar before the batteries are full please? I have a support query in with GE regarding the over voltage issue but don't expect a resolution soon. I may be missing something simple of course 🙂

sponev Nothing immediately springs to mind. Perhaps wonderwatt.com can be used to schedule conditional discharges ("if soc > 80% then discharge down to ..." or whatever it offers you)

DD Thanks for confirming my thoughts. I did think about Wonderwatt but I was hoping to avoid any forced discharge whilst away. I'm probably worrying a bit too much but even though much improved, the latest firmware still isn't quite right and the system does sometimes do unexpected things, e.g. the latest over voltage issues. I guess I'll need to drop on to the system every three or four days and push some back to the grid and hope nothing goes amiss - I'll be nearly a thousand miles away 🙂

sponev One option, if your inverter supports it, might be to just disallow solar charging completely ? Having the pause timer set to just pause-charging all day should do it. An overnight grid-charge to top back up to 60% or whatever you want to use as your baseline. (If 20% of battery should cover base load, that should cycle between 40% and 60% which seems like a reasonable goal.)

You'll probably get clipping on a sunny day, though.

Set the charge rate to something very low so the battery charges but doesn't get enough time to reach 100% ?

I'm not 100% sure the charge rate impacts solar as well as grid charging, but may be worth a go.

TX200 I'm not 100% sure the charge rate impacts solar as well as grid charging, but may be worth a go.

Yes, charge rate impacts both. (But for me, even charge power of 0 charges at about 250W. Pause mode gets it down to something like 28W. Turning eco mode off goes fully to 0.)

DD Same here, I ramp the charge rate right back in the morning to avoid clipping but it always seems to be at a higher rate than I set.

Your strategy above would work but I'd miss out on around £4 - £5 per day av on solar export alone as we have quite a big array. I guess I'll do some remote intervention and keep my fingers crossed!

sponev Your strategy above would work but I'd miss out on around £4 - £5 per day av on solar export alone as we have quite a big array.

If you limit the max charge from solar, you'd probably still end up with the same clipping loss?
I can't think of any option other than stop charging, or discharge to grid outside of peak solar.

DD It will clip for sure during the period when I'm not managing the batteries but the large majority of potential generation will still be realised and exported. The main concern is having the batteries up at 100% for longer periods of time and the inevitable high BMS voltage warnings which result. It's a pain but I'll log in remotely every few days and shove some back to the grid. Overnight use by CCTV and freezers etc will help a bit. If the batteries would simply idle properly at 100% and the voltage not sneak up, it wouldn't be an issue, but unfortunately that doesn't seem to be the case. Hopefully GE sort it soon.

sponev I'm managing this with some forced discharge but I don't really want to do that whilst on holiday.

Is your objection to this because you don't trust discharging in general if you're not there, or simply the practical that you do it manually rather than through timers?

DD The former really. Although it's generally been quite reliable, I have had it "stick" a few times via the app necessitating further intervention. I've also had one full battery trip incident due to high voltage issues - it's the thought of something like that when I'm away which I don't relish. Hence the thought of leaving it all stable at 70% charged or similar and (hopefully) avoid the high voltage issues which then seem to cause additional issues. But seems that's not possible. My son is local so I'll give him a crash course on how it all works in case of issues and he needs to attend. This is what I mean about it being much better than 18 months ago but still not 100% trustworthy.

sponev I have had it "stick" a few times via the app necessitating further intervention.

But was that a manual forced discharge (via the quick settings button on the app), or a scheduled discharge? It's the former I don't trust, but the timed-export works perfectly reliably for me. (Other than it tends to consistently over-run the end time by a little over one minute. Though I've not tested that on latest firmware.)

DD Manual. I can investigate timed discharge but is the issue with not jumping back to eco fixed? Historically it would discharge and not reset eco when done.

sponev I've never had that problem. Was it specific to gen-1, where it was necessary to turn off eco in order to export?

Note, however, that they've reimplemented timed-discharge to do something completely different. But you should now be able to have timed-export and eco on. But there are definitely problems with the UI where it spuriously disables settings - eg I'm finding that if I change the charging target, it decides to turn off the timed-export flag which is completely unrelated. Much safer to tweak the parameters at a lower level of you can.

DD not sure to be honest, I'm gen 2. I'm wary of the app too but it's a lot faster than having to access the portal. If only the job was a bit more stable. GE first line support just came back and offered a slow calibration to try to fix the over voltages, but no guarantees it will work. Not great.