Battery not always discharging when it should.

Generally my system is working well but one annoying thing is I'm still paying for electricity I shouldn't be. I know there's "a few seconds" delay (as stated in the FAQ) between a high draw appliance starting up and the inverter supplying it from solar and/or batt. but quite often (but not always) it's not supplying after some time.

This screenshot shows after several minutes of my heat pump being on:
I have a 3.6kW inverter, it is perfectly capable of supplying the heat pump so that's not the issue. After I took that screenshot it did start supplying 200W but was still drawing over a kW from the grid. I've tried turning off Eco mode and back on again as suggested in other, similar, threads but it hasn't helped.

Any ideas what the problem could be and how to fix it?

Cheers, Mike....

I should have said as well, it's not just a display issue either, the smart meter display was showing 1.3kW being drawn as well.

have you gone into settings and done a "reset to defaults"?

I've not but did turn Eco off then back on again.
As it's Friday the immersion has come on (anti-legionella duties) and the batt is providing 3.71kW according to the GE app so it's working properly now. It seems to be intermittent when it works or not.

Have you ever put any timed export settings in. GE is unable to get Eco working again after export.
The portal can say and show Eco, but without a reboot. it does not work.

Does the heat pump have an inverter (variable speed motor) drive? I wonder if it’s leaking DC noise on the line and confusing the inverter?

If you force the battery to discharge does it help?

Mike-H As it's Friday the immersion has come on (anti-legionella duties)

I know its not answering your question, but potentially you can turn off your anti-legionnella cycle on your ASHP and save a few kW a week as a result. See this article from Heat Geeks. https://www.heatgeek.com/hot-water-temperature-scalding-and-legionella/

We run our hot water at 50 degrees so I’ve turned mine off although curiously the ASHP immersion heater meter still recorded 4kW in June so it must have done something.

geoffreycoan
Interesting read, thank you. I did legionella testing for a while some years ago so it's always at the back of my mind but that article mostly makes sense. Some issues I have against not heating my tank to 60 for an hour or two a week are that it's a 250l tank and there's only me in the house so turnover isn't high. I am considering replacing the 9kW electric shower which the inverter can't fully supply with a tank fed shower to use the heatpump heated water that the inverter can fully supply. That will increase turnover of hot water considerably. The other issue is I only bought the house last year so don't know where all of the plumbing goes, there could well be dead-legs in the system which are a breeding ground for the bacteria. I shall have to consider my options further.
Cheers, Mike...

SteveCook
I didn't know that, seems like a bit of a flaw! But no, I've never put any timed import/export settings in due to not having a suitable tariff for that. Thanks for the info, I will keep it in mind for the future. Hope GE fix that or at very least pop a message to tell you to reboot or it won't work.
Cheers, Mike...

kram
That I don't know off the top of my head. It's a Warmflow heatpump but I don't have the manual/data sheet to hand.
How is the battery forced to discharge, other than setting discharge timers? I don't remember having seen an option how to do this, would be handy to know if you could tell me please?
Cheers, Mike...

A work colleague of mine is currently in an induced coma after contracting Legionnaires on holiday.
It only has to go wrong once for the results to be devastating.

My GE system generally works pretty well but sometimes it just outright refuses to use the battery when it could (or should).

Today 15:25 - 15:55 had a pretty consistent 3kW load, battery was at either 98% or 100%, but instead of using battery it used the grid for most of the import.

This isn't even an issue of BMS being slow to respond, especially over a 30 minute time frame. It's deciding not to use the battery for some reason.

Feels like G1 Hybrid inverters aren't getting necessary firmware updates to correct misbehavior like this. Wound up importing 1 kWh from the grid in this window whilst the battery sat full.

I have this issue too, my system is an AC3 inverter with two 8.2kWh batteries.

LordHippos I think I have a Gen3 inverter (not entirely sure how to check, think all gens have the same model number? GIV-HY3.6) and it's done this. Today it's been fine and used solar and batt. to cover the heat pump. It's done exactly what I would expect it to do. If it is a firmware issue that it doesn't use the batt. sometimes I hope there's a fix in the pipeline.
Like you say, gneerally works very well and I'm generally very pleased with it. Hopefully these wrinkles will be ironed out soon.

Zakalwe Yep, it can be really bad. My heatpump installer said they're trained that you're only supposed to run the immersion every 2 weeks to kill off the bacteria but he always sets them up to do it weekly to be safe.

Mike-H unless it's really new it will not be gen 3.

Mine is GIV-HY5.0 which is gen 1.

Mike-H just a thought but what is your grid voltage showing when it starts playing up? If it is too high the inverter wont fight it and you'll end up importing from grid instead of discharging from battery.

LordHippos Mine went in mid-June.

RHardie I haven't looked at those specific times but that could be it, I know my grid votage is very high. 254V quite often and I've seen 256 many times. Will have to remember to check that next time it plays up like that. If that's the issue then it's a couple of hundred quid for one of GE's voltage regulator devices, hope I don't have to have one of those. Budget is too tight for that right now.

Mike-H no, don't buy a voltage regulator. Get in touch with your electric operator aka DNO and ask them to change the tap on the phase you are connected to, to reduce the voltage.

They might install some kit to monitor your voltage for say a week before making any changes.

RHardie In terms of mine, seems OK on the day, TBat showing 28/29 degrees and SOC showing 98-100% on all the rows shown, just off to the right.

Mike-H Any particular reason you are worried about legionella? Its only really an issue with people with pre-existing respiratory conditions and if the water becomes air born in droplets - typically a shower. (All as far as I can remember) - normal hot water wont be an issue to many.

TX200 Thanks for that info. DNO, that's something different to the mob you pay your bill to isn't it? It's not going to be Octopus?

anglefire I'm planning on replacing the electric shower I have with a tank fed shower for increased flow rate and lower running costs. Currently the 9kW shower costs me around 50p/shower even if there's enough solar/batt. as the inverter can only cover _3kW of it (the other 0.6 covering the rest of the house). Those 50p's add up fast! Also being an electric shower you have to run around in it to get wet. I'm going to kill two proverbial birds with one stone. The solar/batt. can cover the heatpump when it's heating the 250l tank and all I currently do with it is wash my hands so I'm really not utilising all that hot water as well as I could be.

Legionella concerns me enough to want to take some basic precautions because it's potentially fatal. Having worked a short time in an industry in that area I know a bit about it. Also a cousin of mine had "ordinary" pneumonia and it nearly killed him. It was some years ago and he's still got reduced lung function and will have for the rest of his life. It's not to be trifled with. I know the risks in a dommestic setting aren't as high as they could be but I'd rather have the immersion on once a week and be sure. When the solar system is working correctly it can cover the energy demands of it any way so it's basically free so why not is my thought.

Mike-H aye. It's people like manweb or sweb or western power distribution (now known as "national grid customers")

Think you can find this out via this website

https://www.powercut105.com/en/

TX200 Thanks. Seems it's SPEN. I'll have to get in touch with them.

High voltage seems to be a thing round here, my parents live 5 miles away and they've always had high voltage, 250V+. They have a Danfoss inverter that's now somewhere between 15 and 20 years old and my dad is suspecting it's derating due to over voltage but the installer has long since gone so he can't get the pass-code to access the fault log to find out. As a long shot... If anyone knows of some free software to pull data off a Danfoss inverter via it's serial port please let me know!

Mike-H
I went this route, installed a mains pressure tank and gravity shower / eddi etc
I have to say I probably wouldn't if i had my time again. admittedly the shower water volume is great but as for free hot water, yes sort of true but the cost of heating the water from gas as opposed to exporting - say on flux -it does not make financial sense. On the other hand if you are on a variable export tariff and the export payment drops below the gas unit price then the surplus may as well go to the water. keep in mind that there are times when the batteries are charging at their maximum rate and there is still surplus generation.
the whole cylinder system cost 1000's and I do not see it ever paying for itself.
In fact having learned so much from here it has cost an extra few hundred again recently as i added a solar mixer valve to the water output and a destratification pump. The latter i seriously regret paying £300 for as now i know what the mixed water temperature is as opposed to stratified I don't bother turning it on. (clearly will if the lower half stays cool for a few weeks though (legionella)

positor1 I can see in your situation it hasn't quite worked out but my situation is a little different with this being an all-electric house. I have to use electricity to heat the water whichever way I go but using the heatpump which usually draws around 2.5 to 3 kW when heating the water (uses less when running the cnetral heating) which can be covered by the solar/batt. is better than a 9kW shower which I'm always going to be paying for at least part of no matter the solar/batt. status.

That's my logic any way, if you can see problems with it I've missed please do say so before I go ahead with this project!

Mike-H
no in an all electric i can see the decision making is quite different.