i3 battery - usable capacity

[Atommad]

I thought I read that only 18kWh of the i3 battery is "usable" as it preserves a margin at the top and bottom to to prolong battery life.

However, not so. Today I pulled up at a public charge point with only 4 miles range (phew, never had the range go orange before!), plugged in and returned to find I had taken 20.385 kWh on board.

Anyone else experienced similar?

[spitty709]

Atommad said:

I thought I read that only 18kWh of the i3 battery is "usable" as it preserves a margin at the top and bottom to to prolong battery life.

However, not so. Today I pulled up at a public charge point with only 4 miles range (phew, never had the range go orange before!), plugged in and returned to find I had taken 20.385 kWh on board.

Anyone else experienced similar?

Hi Atommad

I believe that the 20.385 Kwh is the energy supplied to the car an an amount of this is lost during conversion to charge the car so 20 odd in equates to 18kw of stored energy.

[Atommad]

That sounds plausible I guess.

Assuming I actually charged very close to the "full" 18kWh then the losses are 10%.

[LordFlathead]

Are these charge points going to be regulated? Or it could turn into a fiasco where you get billed for 20KW when in fact you've only used 18KW.

My radar is picking up about the accuracy of metering, who inspects it and how often. I think it's good to be vigilant!

[Atommad]

Hi Lord F/h

The issue here isn't one of accuracy of metering, it's one of losses during charging. So whilst I did use 20kWh from the charge point that only gave me 18 kWh of charge in my battery. In any case, public charge points do not charge for the electricity used but for the time plugged in regardless of whether you are drawing a full 7kW or reduced power as the battery nears full capacity so accuracy isn't a major concern from the point of paying too much.