OK to regularly charge to 100%?

10 comments started 2022-12-29 last 2022-12-31
GivEnergy ProductsHybridBattery
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#1 sponev

Are the GivEnergy batteries OK being charged regularly to 100% please? Since installation two weeks ago we've been charging to 100% on Octopus Go Faster, using the next day down to around 40%, rinse and repeat. I'm used to charging an EV to 80% but I think the GE chemistry is OK to 100%? The max time the battery sits full is maybe an hour before it starts to supply the house base load overnight.

Should I modify periodically, maybe charge to 80% and then run it lower to give the BMS more scope to calibrate? Cheers.

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#2 TX200

The 100% you see isn't the real 100% - there's a bit at the top and the bottom you can't use.

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#3 sponev

TX200 Thank you, so I guess OK? Any thoughts on the BMS calibration with a broader range of discharge? I guess this will look after itself as the home office ramps up again after the break, but worth knowing. Cheers.

#4 TheDragon (GivEnergy)

Calibration I would do too often, as this does indeed drain to the last drop and fill till full, exercising both safety cutoff limits.
Regular charging remains inside 15 to 95% of pysical capacity, regardless what the SoC reports. an 8.2 100% DoD is really 10.5 and 80%.

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#5 Tim

sponev Using the full range of the battery available to you wouldn't do any harm. If your peak-time use equates to 60% of your battery capacity, you've plenty of scope to play with charging up enough to not hit 4% before the start of the next off-peak window, without charging to 100% every time.

The situation for us is simpler in that our peak rate tariff is nearly 9 times the off-peak tariff rate (39.93p vs 4.5p), so there is a big incentive to ensure that there is always more battery capacity than we need to get from each charge window to the next. In the spring through to autumn, we haven't charged off-peak at all, relying on PV to charge the batteries, but this time of year, it's essential. Some days at this time of year, the PV keeps the house ticking over until dark, meaning we only put say 30% into the batteries off-peak, but over the Christmas holiday with 12 people in the house and the oven on practically all the time and two EVs to keep charged, I just resigned myself to not look at the portal or smart meter until everyone had left. Highest grid import for one day was 70kWh (55 off-peak and 15 peak). Never mind, we had a great time and it only happens once a year.

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#6 sponev

Tim Thanks, I will flex the charge levels across the range a little bit more. I know with my car that an occasional drop of the charge to low level followed by 95% plus will recover a few miles on the BMS although it's marginal.

Our panels did reasonably well today and we found ourselves putting on some spot heating and the immersion for a while to save exporting it, a bit of extra headroom in the battery would have helped there too. Still getting to grips with it but overall very pleased.

I hope the new firmware solves the SoC problem so we can be confident in what we're seeing! So far we seem to have escaped but we're only a few weeks in. Cheers.

Z
#7 Zakalwe

TheDragon (GivEnergy)

TheDragon (GivEnergy) Calibration I would do too often, as this does indeed drain to the last drop and fill till full, exercising both safety cutoff limits.

I thought that end users couldn't and only GE support staff could initiate a calibration?

#8 TheDragon (GivEnergy)

Zakalwe correct. Installer or better account needed.

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#9 IanMac

Tim Do either of your cars do V2L? I've run a socket from the lounge out to the car - Christmas day I powered most of the equipment in the lounge including a 1500W heater from mine. The TV and AV equipment draw about 400w/h so managed to save about 2kW of usage plus heated the lounge quite comfortably.

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#10 Tim

IanMac Unfortunately not. I did register an interest for the Indra trial but we don't have one of the vehicles on their test list. As our visitors have now departed, we only have our own EV; the other and the hybrid were just visiting.