EP11 and C rating/value
Posted: Sun Jun 29, 2025 9:58 am
Hi,
We've just had a couple of EP11 installed and I'm trying to understand how to treat them well. It seems one of the key factors is charging them too quickly, and there is a figure C which you can use to measure this. C seems to be the current which will fully drain the battery in one hour.
As Watts = Volts x Amps, Amps = Watts / Volts, which for the EP11 (10360 watts, nominal voltage 384V) gives
Amps = 10360 / 384
therefore
C = 27Amps
This is the figure given for capacity in Ah on the attached (scrappy) photo of the EP11 EU 2023/1542 document.
But in this document they call it 0.2C.
It seems we want to target something close to 0.2C as the charging current to prolong life, but shouldn't 0.2 C be 27 x 0.2 = 5.4Amps?
We've just had a couple of EP11 installed and I'm trying to understand how to treat them well. It seems one of the key factors is charging them too quickly, and there is a figure C which you can use to measure this. C seems to be the current which will fully drain the battery in one hour.
As Watts = Volts x Amps, Amps = Watts / Volts, which for the EP11 (10360 watts, nominal voltage 384V) gives
Amps = 10360 / 384
therefore
C = 27Amps
This is the figure given for capacity in Ah on the attached (scrappy) photo of the EP11 EU 2023/1542 document.
It seems we want to target something close to 0.2C as the charging current to prolong life, but shouldn't 0.2 C be 27 x 0.2 = 5.4Amps?