Do you any of y'all make an active attempt to level your cells periodically ?

Sunsynk 5kW

SolarMD 14.3kWh

In the quest to give Eskom as little as possible ( i.e. be as efficient as possible ), in the darker months I set the minimum battery charge state to a percentage where I think it will reach 100% charge by the end of the day.  I do this to give the battery a chance to top level and appease the almighty BMS so that it spits out accurate values.  Sometimes it doesn't reach 100% due to general household usage, cloud cover etc. 

Now I only change those timer settings 2 or 3 times a year. I'm not constantly fiddling.  So I'm just curious.  Do you deliberately charge up to 100% once or twice a week in the darker months to give your battery a chance to level the cells ?  Or do you just set your timer to a higher battery charge state percentage so that the cell levelling is done pretty much as a background task ?

Edited April 16, 20242 yr by hilt_ctn
Added detail

Normally the BMS will only start balancing above a certain cell voltage (around 3.45v-3.48v). The BMS will also only recognize and reset to 100% SOC when the pack reaches a set voltage and goes below a set charge current for a set time. Victron's ESS system (when set to Self consumption with batterylife) will set your lowest SOC% according to the amount of charging the batteries get to get the to 100% SOC as often as possible. This means that an algorithm automatically increase the SOC% should the battery not be charged fully in a certain timeframe and vica versa.

Properly charging Lithium batteries is a debate that will probably continue for a very long time. My opinion is that the bloody things are too expensive to not look after them.

1 hour ago, hilt_ctn said:

Do you any of y'all make an active attempt to level your cells periodically ?

Theoretically every day, if enough solar, but on the 15kW I only go down to 10mV, don't know about the 8k2W BSL...

2 hours ago, Czauto said:

My opinion is that the bloody things are too expensive to not look after them.

Damn right !  The plan is to automate this via Home Assistant.  I'm trying to ascertain where that happy place is i.e increase SOC limit so that the battery levels daily ( like it does in the summer months ), or have Home Assistant run a daily task to look at the battery charge history over the last say 3 or 4 days, and if it hasn't hit 100% in that time ( which is when my battery levels ),  a switch is flipped and the battery charges to 100% to initiate levelling

1 hour ago, Kalahari Meerkat said:

Theoretically every day, if enough solar, but on the 15kW I only go down to 10mV, don't know about the 8k2W BSL...

I'm in that position where I have more than enough sun in the summer months, but not in enough in winter.  So trying to optimise as best possible in the darker months.  I can't save every watt.  But if an automation can help, why not !

Edited April 16, 20242 yr by hilt_ctn

2 hours ago, hilt_ctn said:

more than enough sun in the summer months, but not in enough in winter

Mostly enough in summer & winter, except those pesky cloudy days, which, luckily, we ain't getting too many of, but, I have just ordered some more panels and am upgrading the 5kWatter to a 8kWatter to cater for the panels, this should probably see us through, but in the last 4 months, we have had the odd day, where at sunset the battery is only at 80% or even less, those pesky cloudy days... by now, our daily consumption is noticeably down from Feb and early March, just some refrigeration not working as hard now, than when the average ambient temperature in the house was probably around 28 degrees C or more and peaking around 35 or so... no air conditioning as of yet... anyway, the JK BMS is set with parameters that don't scare the bejeezuz out of me and it reports cell voltage differential around 6 to 7mV and basically is charged mostly before 14:00, as for the BSL, who knows, it claims 100% SOC and keeps on consuming Amps like there's a shortage somewhere (the JK usually says 80% SOC or somesuch at that stage, certainly a lot more honest), I hate that BSL's BMS, whatever it is and as soon as I add another 15kW + JK BMS, the BSL will have to find a new home... probably end of winter...