Oscillation in Battery SOC. Charge/discharge cycle under ESS Optimized with Batterylife

[WLiam (Liam)]

Is it typical to see this behaviour with victron system under ESS: Optimized with Batterylife?

Active SOC limit is at 80% as we’ve been having cloudy days. Batteries sit at 80%, then during daytime solar production MPPT charges battery to 83%, then it discharges into loads. And repeat.

If so, why does it make sense to charge and discharge the battery needlessly, rather than inverting the DC power from the MPPT into AC Loads?

Thanks for any help

System Info

Quattro 15kVA

3.2kWp PV feeding MPPT 250/100 rev2

6.3kWp PV feeding ABB Inverter. AC coupled to Quattro on the Load Side

Zenaji Aeon LTO batteries. Qty13 = 26kWh total.

Color Control GX with BMV-700.

[Ramatt]

This hysteresis is normal behaviour and has been debated quite a bit over the years, you can see one of the more recent examples below with some examples of various user solutions.

3% hysteresis around minimum SOC

Hi, I use an ESS system consisting of 3x Multiplus-II, two solar chargers, Cerbo GX and a CAN-connected smart battery (BYD LVS 8.0). My question: Is there a way to disable the 3% hysteresis above minimum SOC? When the load is higher than power coming from the solar chargers, the battery is discharged until minimum SOC is reached. As expected, the ESS switches to ESS #1 mode to prevent further discharging of the battery. But instead of staying at minimum SOC and using grid power to substitute th…

AFAIK Victron are well aware of this and there is no intention to change it as, in their opinion, it works well enough for the majority of users.

[WLiam (Liam)]

Thanks very much for your reply