Battery discharging and pull from the grid

8 comments started 2024-03-08 last 2024-03-08
GivEnergy ProductsBattery
#1 Midlands_Solar

Currently I’m charging my battery to 80% and 1.5 kWh (to be kinder to the battery) between 00:00 & 07:00 and then again to 100% from 12:00 -15:00

This am I noticed the system is pulling from the grid and not the battery, does it need to recalibrate by being charged to 100%?

#2 Cdent

Midlands_Solar can you screenshot your settings so we can see how you've set it up?

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#3 DD

Midlands_Solar I think it's behaving as intended (and as you should want) - the grid is cheap until 7am, so it makes sense to use it instead of the battery.

During the charging window, the battery will hold charge once it reaches its target

(Why top up during peak rate later in the day? Because of round-trip losses, that's less efficient than just running directly from grid. Given your good export rate, may as well charge to 100% overnight.)

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#4 DD

Midlands_Solar does it need to recalibrate by being charged to 100%?

I think calibration (cell balancing) happens down at the bottom, rather than at 100% - I'm trying a new regime where I let the battery idle for the first off-peak hour before I start charging. It didn't do much the first couple of nights, but last night I allowed it to actually bottom out (which it seems to do at 6%), and it drifted all the way up to about 20% by the time I started charging - it's been quite a while since I've visited either extreme, but I do see jumps from 80% to 100% from time to time, which seems consistent.

I think your battery regularly hits both 100% and the bottom reserve, so it's probably in a good state of balance. (Do you ever see reported SoC drifting upwards after the battery runs out?)

#5 Midlands_Solar

Cdent

Sure here you go

#6 Midlands_Solar

DD sorry you're going to have to help me the the acronyms, SoC?

#7 Cdent

Midlands_Solar ok, so because you're telling the inverter to charge the battery until 7am it'll hit the target and then when full keep it at that target until 7am. It'll us the grid after 7am because you've told it to hold 80% until then.

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#8 DD

State of Charge. Just the battery charge % level (eg 80%).