Reposted in this section 29/04.
Hi all,
My system: 7 x 440 PV. H1-3.7-E-G2. 1 x EP11. Work Mode Self Use.
I ran my ASHP to top up DHW at noon today (a short cycle from 33' back up to 43') Battery indicating 100% and lots of PV coming in.
When the water heating was complete the battery level was indicating 99%. Then a while later 98%. Subsequently, most PV energy was diverted to the grid -I was expecting the battery to be prioritised before exporting but that never happened. Three hours later at 5 pm there was 1.13kW PV incoming, of which 12w was to the battery (still at 98%) house 0.11kW and 1.01kW to the grid. Battery temperature was 18.5'. Prior to today I've always seen the battery go back to 100% pretty rapidly in sunshine, today it remained at 98%.
Any comments/observations/tips would be welcome. I've only been using the system for a week, please make allowances! Thanks.
Note from 29/04: Same behaviour today. Battery not charging from solar after heating water. System seems to be prioritising export to grid.
Query from a new user.
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Dave Foster
- Posts: 1850
- Joined: Thu Oct 13, 2022 7:21 pm
That is normal behaviour - the BMS slows the battery charge as it approaches 100% and once it has hit 100% it turns the charge off altogether to avoid damage and over heating. It then decides when to start allowing charge based on battery soc, battery temperature, cell balance, age etc.. but basically it is quite common for the battery to drop a few % before it re-enables the ability to charge.