After having my rig plugged in and ensuring batteries are charged and resyncing SOC to 100%, I notice that over time the SOC percentage at which the system goes into absorption/float slowly drops, about 1% every couple of days. For example, I left a campground on April 26th where I had been plugged in. Left the campground at 100% SOC. My bus has sat since then in direct sunlight with very minimal draw on the system as I have only kept the fridge/freezer running. I have plenty of sun and panel power to be keeping the batteries topped off. Now a little over two months later, the system is going into absorption/float around 70%.
However, The voltages at which it's entering absorption/float seem appropriate. What's causing the drop in SOC percentage and what is the fix? I've noticed it happening for about a year now but would occasionally be in a situation where I could plug in, resync SOC to 100% and restart the cycle all over again.
I have 4x200 watt Renogy panels connected to two 100/30 Victron MPPT charge controllers and Victron 3000 watt inverter/charger along with Victron BMV. Batteries are two 206aH SOK LifeP04 batteries.
Thanks in advance.
