Hello!
AC200PL+B300+B300K.
I am using Timed UPS mode. During day it is drained, during night it is charged.
Is there any upside to set SOC High lower than 100%? Talking from battery lifetime perspective (taking into account the type of battery).
If yes, what high enough value do you suggest? Will 98% be better than 100? 90?
Also, I heard, there might be desynchronization problem if station and expansion batteries not charged to 100 (and not discharged to 0) constantly, is that so?
I would argue that you’re using the device as its intended. The batteries are rated for thousands of cycles, It seems to me that it would be better if your batteries were matched in capacity but if its working the way you want it to work then keep doing what you’re doing. In theory you could get 10 years out of this system. The max lifetime charge cycles rating is from nominal to full charge, so if you made the charge/discharge setpoints say 80% to 20% you may get more life out of the batteries but what’s a reasonable life span anyways? 3000 to 3500 cycles is pretty damn good. These batteries are so robust that I would worry more about other components failing before the batteries.
The primary benefit of a 80% charge cap is for storing the battery for a period of time, unused. The other aspect of this publicised charge cap, is for smaller batteries such as mobile phone and tablets. They are Lithium Ion not LFP, which makes a difference.
I have an AC70 permanently connected to the Grid, which powers WiFi router, fibre optic conversion box and security cam hub. It has no time setting and a small constant 25W load. Around once a month, I disconnect it, drain capacity with other devices to 20%, then give it a full recharge, just to give the AC70 some exercise. The other plus of this is, that in disconnecting, the WiFi router gets a reboot, which has been noted to improve service.
I am considering, using an on/off timer at the power outlet, to only charge during off peak daylight, when the roof solar charges it. 25W over 24 hours is 600W per day and 219kW per year. Charged in Silent mode at 300W.
Where I am, daytime off peak is 5 hours, more than enough to replace the 500 or so Watts used from battery and within battery capacity.