Battery going from 100 to 10 instantly
Posted: Sat Mar 21, 2026 5:28 pm
Having real issues that have developed over 5 days.
I’ve noticed that the discharge rate of my five Mira HV25 batteries has been lower than expected. Looking into the data, there appear to be large, unexplained jumps in the reported state of charge.
Towards the 19th and 20th there are dramatic changes in the SOC over periods of minutes where there is no obvious drain (no car charging or otherwise)
I also noticed a software update was available for the Wi-Fi module, which I installed on 20th March. After updating, I reset the system and checked the voltage of all five batteries, which are consistently reading 53.34 V. I’ve been monitoring the system since then, but the behaviour still seems unusual.
One observation is that the data polling interval now appears to be around 10 minutes, whereas previously it was about 4.5 minutes. The software update documentation suggested it should update every 5 seconds, so this may be related.
Today 21st March, it was all over the place. Was 100% all day, then when the sun went down, went to 10% instantly. Voltage checked again and each cell is 53.4v. BMS showing single green SoC light.
Any help appreciated.
I’ve noticed that the discharge rate of my five Mira HV25 batteries has been lower than expected. Looking into the data, there appear to be large, unexplained jumps in the reported state of charge.
Towards the 19th and 20th there are dramatic changes in the SOC over periods of minutes where there is no obvious drain (no car charging or otherwise)
I also noticed a software update was available for the Wi-Fi module, which I installed on 20th March. After updating, I reset the system and checked the voltage of all five batteries, which are consistently reading 53.34 V. I’ve been monitoring the system since then, but the behaviour still seems unusual.
One observation is that the data polling interval now appears to be around 10 minutes, whereas previously it was about 4.5 minutes. The software update documentation suggested it should update every 5 seconds, so this may be related.
Today 21st March, it was all over the place. Was 100% all day, then when the sun went down, went to 10% instantly. Voltage checked again and each cell is 53.4v. BMS showing single green SoC light.
Any help appreciated.