Display maximum value of multiple sensors

[chfink0]

Hello there,

I have multiple cell balancers (part of a Battery Management System in a solar battery) connected to Home Assitant and each of those 5 reports a maximum cell voltage within this battery string which is crucial for the battery security and health.

As those five balancers belong to one big Battery (with 100 cells) I would like to setup a virtual sensor which shows the maximum of the individual readings.

Example:

Input:
max cell voltage balancer 1: 3,60
max cell voltage balancer 2: 3,61
max cell voltage balancer 1: 3,60
max cell voltage balancer 1: 3,62
max cell voltage balancer 1: 3,59
Result:
Virtual Sensor: max cell voltage in battery: 3,62

How can I include this virtual sensor?

Thank you in advance!

[123 (Taras)]

I would use a Trigger-based Template Sensor.

How are you currently receiving data from the balancers? Is it a separate sensor entity for each balancer or a single sensor receiving data from both balancers?

[tom_l]

If they are seperate sensors you can use this:

Min/Max

[chfink0]

Excellent, exactly what I need, thank you very much!!

[123 (Taras)]

In your first post, the sample values were as high as 3,62 volts. In the screenshot you posted, the Max sensor is reporting 3,278 volts.

Have the maximum cell voltages actually decreased by 0,3 volts?

[chfink0]

It depends on the state of charge. 3.62v is almost the maximum voltage when state of charge hits 100%, 3,27 is more like 60% battery state…

[123 (Taras)]

I understand it “depends on the state of charge”. Your first post shows one value as high as 3.62. I had expected to see that value reported as the “maximum value of multiple sensors”. However it doesn’t appear in your screenshot. I had not expected to see all the voltages noticeably lower by the time you created a Min/Max sensor. I’ll attribute it to my unfamiliarity with how your Battery Management System operates.