Blog - Tests and diagnosis

Email: Unfortunately, I do not have good news. We faced again a strange situation. The system was not used in the past 2 weeks, there was no grid shortage, the system was not used,  and the BMS show that the battery pack was full, please see below the inverter log.

It is obvious from the voltage that there is some load connected to the battery that keep discharging the battery. The voltage of the battery dropped as low as 45V. 

This is very dangerous that some of the cells may be depleted bellow 2.5V. And the pack will become damaged. ⛔⛔⛔

There is no possibility that the cells discharge by themselves. ❗ ❗ ❗ These cells have no self discharge and they are professionally tested bin the factory and before the delivery to the customer. There is no way that these cells “discharge by themselves”. It is always the failure of the equipment that is connect to the cells.

You need to investigate what is discharging your battery. There may be some equipment connected to the battery pack that keeps discharging the cells. If you have 700AH cells, and they go discharging in 14 days (336 hours), it means there is some equipment that drains about 2 Amps per hour from the pack continually.  Please check your installation and verify everything.

Please note that this situation has nothing to do with the warranty of the cells. The cells work OK, but you have some problem with your installation that causes the cells to be discharged and depleted.  You need to check, find your problem and make the solution.

If you keep discharging the cells too low ⛔⛔⛔  you will definitely damage them. 

NOTE: In the installation of 16 cells, you should never go bellow 48V.  Your diagram shows you let the cells discharged too low. This is the mistake of your installation and it is nothing to do with the warranty of the cells.