Hi,
I have a 1 year old EP11 + KH9 inverter and in recent weeks I'm seeing some (30%) loss of capacity / SOC being out of sync.
I first noticed that when using the electric shower (9kw) at low SOC it prematurely resets to 10% before it should, then on this day (see screenshot) it reset from 30% to 5% in a 3 minute interval.
And looking at the data im seeing something similar on the top end as well, on charge its going from 80% to 100% in a 3min interval, sometimes from 70% to 100%.
My daily schedule is fully discharge by 00:30, charge from 00:30 to 05:30 at 3.6kw. Then i set priority export for the day, with a force discharge 17:00 to 18:00.
Any thoughts?
You should probably just do a calibration on the top/bottom ends of the capacity.
A video by Will here to explain things better.
A video by Will here to explain things better.
Hi,
Thanks for your reply, and video!
I do understand the need for balancing, but im not sure why its not happening automatically with my schedule?
I charge from 10% to 100% each night, on this day for example between 02:20 and 05:30 its sitting at 100% in FORCE CHARGE mode, how else should I balance on the top end?
Cheers,
Adam
Thanks for your reply, and video!
I do understand the need for balancing, but im not sure why its not happening automatically with my schedule?
I charge from 10% to 100% each night, on this day for example between 02:20 and 05:30 its sitting at 100% in FORCE CHARGE mode, how else should I balance on the top end?
Cheers,
Adam
From what I understand, it's enough to hold it at 10% for a few hours and 100% for a few hours (latter you already do)
Do you have an indication of the state of health of your battery, you can dig this out of your app.
If you have solar, it might be worth charging to 80% and letting it charge up to 100% during the day. For my own EP11, I was charging overnight to 100%, but letting it release energy at the end of the cheap charge window, and even doing a forced discharge for an hour (you can vary this time) and ran the Inverter in 'Feed-in' mode. Doing this, I would see the battery discharge to 55% ~ 60% but it would creep up during the day from PV energy to around 80% give or take.
Do you have an indication of the state of health of your battery, you can dig this out of your app.
If you have solar, it might be worth charging to 80% and letting it charge up to 100% during the day. For my own EP11, I was charging overnight to 100%, but letting it release energy at the end of the cheap charge window, and even doing a forced discharge for an hour (you can vary this time) and ran the Inverter in 'Feed-in' mode. Doing this, I would see the battery discharge to 55% ~ 60% but it would creep up during the day from PV energy to around 80% give or take.
Hi,
The battery SOH is 95% with 353 cycles.
OK ill try and do a slower force discharge, and leave it at 10% for a bit longer before recharging.
Am I right in thinking that once the battery reaches 100% it stops balancing then?
If so this seems a bit counterproductive if it knows there are still unbalanced cells..
Thanks for your help!
Adam
The battery SOH is 95% with 353 cycles.
OK ill try and do a slower force discharge, and leave it at 10% for a bit longer before recharging.
Am I right in thinking that once the battery reaches 100% it stops balancing then?
If so this seems a bit counterproductive if it knows there are still unbalanced cells..
Thanks for your help!
Adam
For your reference, 96% SoH with 346 cycles (around 15 months)
Ideally leave it at 10% for a couple of hours, and you may have to repeat this a few times for the cells/BMS to calibrate.
In normal operation (self-use) the SoC would reach 100% and drift down to around 96% or so before allowing it to charge again. Maybe you need to check what the SoC is doing on your feed-in mode, to see if it drops down in cycles? During a normal charge event, the power should decrease above 95% (or so) and really drops down above 98-99%. You won't see this very well with the slower cloud reported figures. I am not 100% sure what the system does at 100% SoC, all I can say is it doesn't like to sit there, hence you normally see it discharge a few % before climbing back.
On my own system, KH7 with EP11, I will see the SoC creep up even in feed-in mode, as seen by others too. So could be an idea to stop at 80%, or charge to 100% as you are, but discharge around 20% off quickly. Leave it in feed-in mode, and you might see your SoC creep up. You can then allow it to charge to 100% before 4pm if you need the power, so that it does not sit too long at 100% (apart from doing a calibration here and there to hold 100%)
FYI: I was at 76% SoC at 10am, and now 79% within 90 mins despite being in feed-in mode.
Ideally leave it at 10% for a couple of hours, and you may have to repeat this a few times for the cells/BMS to calibrate.
In normal operation (self-use) the SoC would reach 100% and drift down to around 96% or so before allowing it to charge again. Maybe you need to check what the SoC is doing on your feed-in mode, to see if it drops down in cycles? During a normal charge event, the power should decrease above 95% (or so) and really drops down above 98-99%. You won't see this very well with the slower cloud reported figures. I am not 100% sure what the system does at 100% SoC, all I can say is it doesn't like to sit there, hence you normally see it discharge a few % before climbing back.
On my own system, KH7 with EP11, I will see the SoC creep up even in feed-in mode, as seen by others too. So could be an idea to stop at 80%, or charge to 100% as you are, but discharge around 20% off quickly. Leave it in feed-in mode, and you might see your SoC creep up. You can then allow it to charge to 100% before 4pm if you need the power, so that it does not sit too long at 100% (apart from doing a calibration here and there to hold 100%)
FYI: I was at 76% SoC at 10am, and now 79% within 90 mins despite being in feed-in mode.
Yeah i see the creep up even on feed in priority as well, most days it will discharge a bit in the morning, then it will creep back to 100% if we have a good amount of pv. I guess the question is though is it actually balancing during this? because if so i don't see how my system could have got out of balance as it does this most days.
Ill adjust my schedule and see if it will re-balance.
Ill adjust my schedule and see if it will re-balance.