Why does Pylon-Monitor show 98 % state of health when my inverter shows 94 %?

Question

I have 4 × US3000C in a stack, the most recent acting as master. My question relates to the SOH as reported by Pylon-Monitor. My inverter reports the SOH as 94 %, but Pylon-Monitor says 98 %. All other parameters reported seem consistent with BatteryView, for example. The batteries are of different ages and the SOH of each varies across the stack. Great product by the way — very pleased with it.

Pylon-Monitor · Accepted Answer

Thanks, glad you're happy with it! Here is exactly what's happening: Pylon-Monitor's combined SOH is the average of each battery's own reported SOH. It reads the value each US3000C sends over the console link and averages the four. Since your batteries are different ages with different SOH values, that average won't necessarily match your inverter.

Inverters often compute a pack's SOH differently — for example weighting it toward the weakest battery in the stack, since that is what actually limits the pack's usable capacity. Both numbers can be "correct": they answer slightly different questions.

You can see each battery's own SOH on the dashboard, in the per-battery table. That shows the spread across your four units and which one pulls the average down.

Why does Pylon-Monitor show 98 % state of health when my inverter shows 94 %?

Short answer