Charging 80 or 100%

[eNate]

Why? Because it was 2014 and BMW was new at this coming off of the Active-e experiment and didn't know how to market EVs to the masses, and felt the KISS principle was the right way to go with respect to charging and not alternating their customers.

That would be my guess. They've certainly charged their tune with their current EVs.

As noted earlier in this thread, when 100% is indicated, the battery is at around 95% actual.

Nobody needs to "miss out" on mileage.I keep my charge around 80 and when I need full range I charge to 100.

 

[Gonville]

I actually know the answer to this because it's quite the controversial subject in places like Facebook. Since 2021 (2022 models in the UK) had the new i4 i5 and i7 rolling out, they modified that " I Series " book to be more generic knowing the i3 was done for, the other models have completely different chem and BMS ....but yea the handful of owners with i3s got a "rogue manual" ...kinda funny.

I agree 100% with the 100%. JTylee is 100% correct too. The manual was changed in February 22 to contain the ‘generic’ newer i series advice. The critical thing is that the i3 does passive top end cell balancing when charge is complete and we have no stop percentage. I.e. charge it to ‘full’.

Conversely the newer models have a ’stop’ at 80% as the default in the same way that Tesla does with its active cell balancing as it charges. (I have no knowledge of the BMW cell balancing technique in the i4).

The newer manual therefore is unfortunately going to completely unbalance the pack if people follow that advice.

This is what happened to my original 60Ah when I only charged (on free vend) during retail visits and never past 80%. Big mistake took months to recover by leaving it plugged in (coincidentally when free charging ceased). 35 miles at 100%. Eventually went back up to 70 miles.

 

[Gonville]

Now excessive rapid charging WILL degrade the battery if used too much.

I have some Tesla charts that claim to show, from users, that those who only ever used supercharging had lower capacity loss over time. Data was collected by a Belgian user groups so has been somewhat challenged but I don’t see as we have an excellent heat management system (better than Tesla?) and a very slow charge curve after 85% (ok different for all three models) why rapid charges would be an issue? It’s the heat at 100% for a single cell and we don’t ever get to 100% anyway (unlike Tesla) and keep cool?

The outliers at the top were apparently supercharger only but I guess self reporting is a little unreliable.