Keeping a lithium battery full all the time will reduce its lifespan. After 10 years a battery will loose 17% of its capacity if its average state of charge is 50%, and it will loose 28% of its capacity if it is full most of the time (*).
TAO BMS can control the chargers to stop the charge at a set SOC and restart them when the SOC gets low. This feature avoids keeping the battery full most of the time. You can define and select different charge profiles based on your anticipated energy need and production capacity.
(*) at 25°C with an average of 200 full cycles per year – see this article for more details
Lets look at some situations where it is useful:
You will need to have a full battery:
Whether tomorrow will be rainy, you need to run the water maker or are planning a night navigation, you want to be sure the battery is above 95% SOC before the sunset (if your charge sources can do it!).
You can set a charge profile between 95 and 100%, like that the BMS will only stop the chargers when the battery is full (avoiding the float stage that is bad for the battery), and will restart the charger if the SOC drops below 95%.
You are away and your installation will not be used for a while:
But you still need minimum power for the safety equipment and fridge. In that case it is healthier for the battery to stay around 50% SOC. You can set a charge profile to stop the chargers at 55% SOC and restart them at 45% SOC and you do not have to worry about the battery being full (with chargers in float mode) for a long period or being overcharged.
If your installation is not used for an extended period, you program the BMS to let the charger go to 100% SOC at regular intervals, then return to the selected charge profile.
You want to give more time to the BMS to balance your cells:
By using a charge profile between 99% and 100% SOC, the chargers will be stopped and restarted regularly to keep the cell voltage at the upper limit and give plenty of time to the balancer to do its job.
It is summer time and your battery is always full before lunch:
In that case you may want to limit the charge to 80% SOC and wait until the SOC has dropped below 35% to restart the chargers (make sure the low SOC is high enough so that if it is reached at the end of the day you have enough energy to cover your needs for the night)
At any time you can restart the chargers by pressing the RESET button on the LED panel
How to make the BMS do all of that?
Just create the Charge Profiles you need
Then on the Monitor select the “Charge Profiles” option and enable the profile you want to activate: