Aside from all the first drive reviews that came out yesterday, a few technical details disclosed by BMW seemed to be relatively under-reported but equally as interesting.
First we have the eDrive40 and M60 power curves (via
paultan.org), in 3 different modes: Personal/Sport/Boost.
For the eDrive40, Boost mode offers a quite noticeable increase of power. For example at around 60km/h, power went from ~225kW to ~245kW, a 9% increase. On the other hand, Boost mode in the M60 has a very minor impact and it's only visible near 60km/h.
A few more slides attached showing the charging dynamics, battery layout, and motor design details. (via
Out of Spec Reviews) A few observations from my untrained eye:
- Compared to the iX charge curve which is stepped, the i5 starts at a higher charging power (205kW) and the rolloff is a smooth curve. The smooth curve most likely would result in a better trade off between charging speed and battery longevity.
- With the i5, instead of following a fixed charging power vs. SOC curve, charging power can now begin at near peak regardless of SOC starting point. For example, when charging a half-empty battery (SOC = 50%), instead of starting at a rate of 120kW, the i5 allows for 200kW at the beginning of charge and rolls off from there. Judging by the area difference in the plot, this represents an almost 40% reduction in charge time! (from 50% to 80% SOC) Edit: this feature seems to be also available on other models via an OTA update.
- From the battery cell layout diagram, it's clear that BMW is fully utilizing the drive-shaft tunnel (rear floor hump) by stuffing 2 smaller battery modules in there. It's still a compromise due to chassis-sharing, but at least we know the space isn't wasted.