How long should it take for a US5000 battery to equalise.
My system is a grid connected Multiplus 2, Cerbo GX, 20 x 400W panels running to 2 x 250/100 MPPT chargers with 2 Pylontech US5000 batteries.
I’m using ESS with a scheduled overnight charge of the batteries to 100% SOC.
This system has worked perfectly for 18 months.
Recently I asked my supplier to fit 2 more US5000 batteries, to give me 4 in total.
When the new batteries were fitted, 1 went into run mode and worked as expected from first powering up, the 2nd went into idle.
The supplier said they checked all four Batties, they were working as expected and the battery in idle was just equalising and it would sort itself out over the next few days, just run the system as normal.
Since installing the new batteries a month ago, 1 of the new batteries has never gone into run mode from idle and the SOC has never gone over 96%.
I’ve run the system in keep batteries charged for several days with no effect.
Has anyone else seen this.
Is this expected behaviour and will it eventually sort itself or have I got a defective battery.
Is there anything I can do to get the battery running normally.
Yes, pylontech batteries do take a long time to eualise - the balancing current is only 50mA.
When connecting new packs to an existing system, one normally monitors the terminal voltage of each of the new batteries, and only connect them into the system when they are within 0.1 to 0.25V of the working system.
This maybee already done on the upgrade by the installer. It’s advised for either of the two new batteries to be set as the master, CANbus cable from one of them to the Cerbo GX and then link out the others as they may have newer firmware.
If the older batteries maybee have a different firmware there is a Pylontech SOP procedure on how to upgrade them all the the same/latest firmware.
This may help.
Also In terms of power cabling has each pair of US5000s got a cable set of same length to busbar or switch to ensure equal current sharing?
The battery that is in idle is the Master, followed by the 2nd new battery then the 2 old batteries.
Installer said the old batteries have older firmware but it doesn’t need to be updated as long as the master is the newest.
I don’t have the battery view software or the firmware files.
The installer was not very keen to give me copies of the firmware or software.
The 2 new batteries are wired in parrellel using the short Pylontech cables., then connected to the Lynx distributor.
Similarly the 2 old batteries are in parrellel and connected to the Lynx.
I have connected the batteries individually and all 4 batteries individually charge to 100% and discharge as expected so seem to work OK separately.
I charged them all to 100% individually before reconnecting them back together so they should have very similar SOC, but still the same battery stays in idle.