Hello. I’ve installed Victron Multiplus2 47/5000/70-50 with Cerbo GX and Pylontech US5000 as grid backup solution for outages. Everything works pretty well with recommended settings (no ESS), except one thing which concerns a bit. After being recharged with current over 10A, the system at 100% SOC immediately starts to discharge at minute consumption rate of 5W and does so until battery voltage drops below 50V and SOC goes to 99%. Then Multi charges back Pylon to 100%, voltage up to 52.4V and cycle with discharge of 5W starts again. If initial recharge happens with 10A or less, the battery after topping to 100% stays in idle (all its leds go out and only stand by one blinks).
I tried to factory reset both Multi and Cerbo, switched off UPS and PowerAssist functions, but no changes to behavior. The only cure is to switch briefly Multi to Invertor only state and immediately back to On. It charges for a minute with small current and battery goes to Idle mode.
I suspected 5W was Cerbo consumption as I measured connecting it to battery alone. But then why Multi isn’t supplying it? And why does no discharge happen after charging with current lower than 10A? I also tried to supply Cerbo with another battery, but Pylon remained showing 5W discharge. Same time Multi reports voltage drop on battery but no consumption rate of 5W. Seems something drains it on DC side. Is it normal and I should leave battery cycling between 99 and 100%?