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Self-use , but PV prioritizing export and not charging battery

Posted: Thu Sep 07, 2023 1:14 pm
by karan
Hello,

I had my PV system installed a year ego and has been working fine.
I only noticed this last few days, that my battery is not 100%, even when PV is on full blast. the load is only 233 watts, while the PV generation is at 1.5kw and battery is at 90% and it is getting charged with 4w while the rest is exported.
My setup is self-use and so I would expect to charge batteries first before exporting to the grid.

What's happening !

Thanks

Re: Self-use , but PV prioritizing export and not charging battery

Posted: Sat Sep 09, 2023 11:54 am
by Dave Foster
The batteries do self limit themselves when they are over temperature, so it is possible what you are seeing is the BMS throttling the battery charge to avoid damage.

What batteries do you have fitted HV, Mira, ECS ?

It would be a good idea to check your battery firmware versions as there have been a number of improvements in stability and temperature control over the past 6 months, you can do that by going to the inverter panel and clicking Enter, About, Bat Ver - it will show M:xxxxx and S:xxxxx can you post what the versions are and I can check to see if they are up to date.

Re: Self-use , but PV prioritizing export and not charging battery

Posted: Sat Sep 30, 2023 11:55 am
by ramsden187
Is your battery max charge set to 90% perhaps? It's normal to limit charging to e.g. 90 or 95% to prolong battery life. Its in the battery settings.
If your systems firmware was recently updated (mine was last week i think) it also resets some of the settings, so even if it wasn't set to 90% before it might be now.

Re: Self-use , but PV prioritizing export and not charging battery

Posted: Sun Oct 01, 2023 12:10 pm
by calum
The MaxSOC parameter only limits the battery charge when charging from the grid, when charging from solar it should charge to 100%

However as Dave mentions the BMS can intervene to protect the battery.