Normally, manufacturer of EV cars publish the usable battery capacity of their cars. For my Kona EV, the published capacity was 64kWh, the real capacity was actually closer to 67kWh. I did a lot of obd2 data recordings and I was able to confirm this. For the I5, I notice that at 100% SoC display, the bmsSoC is actually 97% and at close to 0% display, bmsSoC is about 4%. (For the Kona, bmsSoC was 97% as well at 100% but it was 0% bmsSoC at 0% SoC display, like no margin at the low end). So about 93% of the real battery capacity is used. This would mean that the real battery capacity should be around 83kWh (based on the published battery capacity of 77.4kWh). My analysis of the recorded obd2 data shows an actual usable capacity of around 72kWh... Which would align with 93% of 77.4kWh. this is a bit unusual from Hyundai that the published battery capacity is not the usable capacity.
After more investigation of the usable capacity of the battery, I observed that the Remaining energy after recharging to 100% varies in function of the ambiant temperature. I'm in Montreal and weather is low during this time of the year. Last week it was -3 degC when I recharged to 100% and the remaining energy value was 72 kWh. Today, the weather was 3 degC and I got 73.5 kWh of remaining energy at 100%. Probably with even warmer temperature, the remaining energy at 100% would get closer to 77kWh... Is there anybody using Car scanner, currently living in a warmer climat, that could test what he gets as remaining energy at 100%?
I watched Bjorg Nyland's test on a Ioniq 6 where he drives it until the battery is dead. It demontrates that there is a remaining 3 kWh when the indicated SoC is at 0%. The BMSSoC is at 4.5% when the indicated is at 0%. I noticed it when I discharge my I5 below 10% SoC that the BMSSoC was still 4% higher. I though it was a lower buffer to protect the battery. But it is a usable buffer. This means that there is a real 77 kWh usable capacity. 74 kWh for the 100 to 0% indicated.
