You may have noticed your AlphaESS app showing the battery at 100% State of Charge, but the system still appears to be charging. At first glance, that can look a little strange. If the battery is full, why is energy still going into it?
In most cases, this is normal battery behaviour.
100% SOC Is Still an Estimate
The app then turns all of that into a simple percentage for the customer.
Because of this, the battery may be very close to full and already display 100% while the system is still completing the final part of the charging process.
A simple way to think about it is: 100% means the battery is effectively full for normal use, but the system may still be finishing the charge.
The Battery May Still Be Balancing
This is normal battery management and helps the battery operate more consistently over time.
Reaching Full Charge Also Helps Keep SOC Accurate
Getting the battery to the top of its charge cycle is also useful for the system itself. Battery voltage does not change evenly as the battery charges and discharges, so estimating exactly how much energy remains is not always as simple as looking at the voltage. Reaching the top of the charge cycle gives the system a useful reference point and can help keep the SOC percentage shown in the app accurate.
This is why you may sometimes see the battery sit at or around 100% while a small amount of charging is still taking place.
Charging Power Should Normally Reduce
There is also an important difference between normal charging and what happens right at the end.
Earlier in the charging cycle, your battery may be accepting several kilowatts of power. As it gets close to full, that charging power will normally reduce significantly.
You may still see some energy flowing into the battery in the app, but it is usually much lower than it was earlier.
The system is not simply continuing to charge an already full battery. The Battery Management System is controlling the final stage of the process and keeping the battery within its normal operating limits.
Why Might You Notice It More on Some Days?
You may not see this every time the battery reaches 100%. How long the final charging and balancing process takes can vary depending on things such as temperature, how the battery has been used recently and how closely balanced the cells already are. You may also notice it more if the battery has not reached a full charge for some time.
When Is It Worth Looking Further?
A small amount of charging for a period after the battery displays 100% is generally normal. It becomes more unusual if the battery continues charging at a high power level for a long period, the SOC starts moving unexpectedly, or the system reports a warning or fault.
That is different from the normal final charging and balancing process.
Final Takeaway
If your AlphaESS battery reaches 100% but you can still see some charging, it does not necessarily mean anything is wrong. The system may simply be completing the final stage of charging, balancing the battery cells and making sure the SOC reading stays accurate. The easiest way to think about it is: Your battery is full for normal use, but the system may still be finishing the job behind the scenes.