Could anyone clarify if you set the AC charge limit on a battery to a % lower than 100% to charge the battery at a night time tariff, if excess PV generation charges the battery during the following day will the battery charge up to 100% or the % set on the charge limit?
With the spring coming with longer days, higher sun and more PV… i want to wind back the night time charge on Octopus Go and utilise the PV to charge the batteries (we have a 2xAC3.0 system)…
I can confirm that on our system, a 3kW inverter & 2x8.2kWh batteries, solar PV, during the day charges up the batteries to a higher setting than the "Timed Charge" limit (if there is sufficient generation).
However, when the "Timed Charged" setting is lower than 100%, on our system, it only charges up to 1% below the setting, during the "Timed Charge" period, and then changes randomly discharging & recharging 1% until the end of the "Timed Charge" period.
Thanks Woodlands .. thats interesting.. i have the two Ac3.0 inverters and I am seeing now that I have set the charge limit to 80% that this morning one battery is charging the other - taking it above the 80% ac charge limit - so supports your observations , but at the coat of discharging the second..! And incurring the losses of two inverters at the same time - not very efficient… i assume once the battery reaches 100% any excess PV will recharge the 2nd battery again?? Must be a better way than this to charge 2 batteries through 2 inverters?
Maybe just wind back the charge limit % on one battery?.. keeping the other at 100%?? Any thoughts?
This is interesting behaviour and doesn't seem optimal. I have been charging to 100% overnight in winter, but last night experimented with a 90% charge.
The constant discharge/charge behaviour through the inverter must be very inefficient. I don't see why the same behaviour as charging to 100% can't be implemented. @Danlambert (GivEnergy) can you give us a steer?
Just as an update, I have found that at the moment, I am reducing the % limit of AC charge at night on just one battery...ie set to 50% to achieve an overall 75% charge overnight..and this has stabilised the two inverters swapping energy and charging/discharging.. As the days get longer and sunnier, I can foresee this going down to 0% nighttime charging on one (50% overall charge) and then after that, we will see how reducing the second battery %limits after that!