recovering a flat battery UK ONLY

When the battery displays very low voltage and either no lights illuminate on the front or the inverter triggers an F56 Fault, there are several options we can attempt to charge it.

Using a multimeter to check the battery voltage, if it reads above 40 Volts, we can proceed as follows:

1/ If there is sufficient PV being generated, we can first access the battery settings and switch to AGM V , if there is not sufficient PV production then you can either set a grid charge to the relevant time when on site or turn OFF  Use Timer and while there is grid present the battery will take a trickle charge if the following steps are set >

Then, go to the system settings and, if not already selected, change to Zero Export + Limit To Load Only. This will bypass the Load and direct all PV energy to the battery. 

Also make sure if doing a grid charge that Grid Signal and Grid charge are both checked and Grid Charge in Grid start is set to 10% which is the lowest available setting .

Also in battery settings change the Shutdown and Low Battery to 38V and also the Batt Empty V to 41V as this is the lowest we can set this ,

 If you observe a trickle charge going to the battery, allow it to remain for an hour as the battery will be in protection mode until it surpasses approximately 5%, at which point it will begin to increase the charge. If we can elevate the battery above around 10%, you can revert to the normal settings, and we recommend executing a brief grid charge to raise it above the lowest SOC percentage. Please bear in mind that if still in AGM V mode it will not read the correct BMS % so we suggest let the battery get to at least 2 power lights before taking off AGM V .

Please bear in mind while in AGM V there will be no BMS so please ignore any readings on the BMS as these will not be accurate until put back into lithium battery mode 

2/ If this method proves ineffective, you may try using an external DC charger. If you have access to one, you can request a document that outlines this method and suggests various types and models of compatible chargers.

If your reading on the multimeter is below 40 Volts, it is recommended that we will ask our 3rd line support team to issue an investigate further to see if it recoverable or not .