What is the Battery Maintenance Function?

4th January 2023

The Battery Maintenance Function is a smart piece of technology that keeps your battery in better condition over the less sunny, Winter months.

During Winter time, limited solar generation means it’s rare for your battery to get to 100% from solar alone. The SOC (State of Charge) may slowly drift to a low level and as such, put your battery in sleep mode to prevent damage to the battery cells. 

The Voltage Curve is quite complex with LFP batteries. It requires a complicated algorithm to calculate the batteries State of Charge (SOC). Over time, the battery SOC may drift. This means that the calculated SOC is not the actual SOC. When the battery is charged to 100%, the battery will re-calibrate and the SOC will be accurate once more.

Soltaro has developed a Battery Maintenance Function which raises the Minimum SOC every day that your system doesn’t charge to 100%. This function prevents batteries going flat during the winter time, when there is limited solar generation. This clever function increases the reliability and performance of our solar batteries.

How do I know if my battery is using the Battery Maintenance function?

You may notice that your battery is not discharging down to 10% as it does during ­sunnier months. For example; your battery discharges, but stops at 20%. It then draws power from the grid. This is the Battery Maintenance Function working. 

Providing your battery is still charging above 20% then it is working correctly. This function keeps increasing the minimum SOC every day that it doesn’t charge to 100%. This will continue until it reaches 95% Minimum SOC. Once your battery charges to 100%, it re-calibrates and the minimum SOC resets back to 10%.

Will I be at a loss financially for not discharging down to 10%?

No. The energy is stored in the battery for the next time you charge to 100%. As soon as the battery re-calibrates, you will have a full discharge cycle down to 10% available.

How can I prevent this from happening to my battery?

If you are charging your battery from your excess solar alone, then this function cannot be avoided. It’s very common that homeowners have lower overnight tariffs so setting a scheduled charge overnight to optimise your battery use will mean you are charging to 100% more frequently. This means that the Battery Maintenance Function is not required and will not be used. However, If you would like to charge your battery overnight, then please contact Soltaro and we can assist you with setting this charge schedule up for you.

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