We’ve set up a new system, using a Victron MPPT 250-85, with 2kw solar on the roof. We have two 12v Renogy 100ah batteries in a series 24v set up. We have a Victron Battery balancer, set up according to the manual specifications, with inline fuses. The MPPT has been set to the battery charging voltages specified in the manual, 28.8v. When the charger brings the voltage up to this voltage, at 28.7v, the balancer alarm relay is rapidly triggered on and off, until I flip the breaker on the solar and the voltage drops. It clicks on and off several times a second. We have removed the batteries and charged them on a smart charger to try and balance them better but it still happens. The only explanation I have is that the voltage is hovering at the alarm triggering level, and this causes the relay to be energised and released is quick succession. Everything is set up as the manual states and I can’t imagine this is the first time this situation has occurred. Am I missing something?
The problem could be that the batteries are not suitable for series connection (each BMS operates independently, so combined operation is not possible), and that the BMS simply shuts down uncontrollably in the event of OVP or UVP.
Buy suitable batteries whose BMS can be networked, or buy a ready-made, suitable 24 V battery with 8 cells.
Good evening,
Sorry to say, the battery balancer is made for batteries without a BMS, even better, lead acid blocks primary, it does not work with the batteries you have, it’s actually written in the balancer manual.
So, take the balancer off and try to return it to your vendor/supplier, but I think you bought it from …? Internet without asking it would work with the bats you have, correct?
The good side, your batteries will work ok without it, batteries are never intended to put in series actually, single cell lead acids (lithium, etc) do, up to the voltage you want, so, the balancer was made for the 6/12 cell monoblock batteries in series to give those somewhat of a longer life in between blocks, and it does of course like a BMS…
Regards, Jeroen.