Full charge shows only 64 miles is this normal?

[Neil]

I'm hoping this is a reasonable topic to bring this up on since my full charge is much less than 64 miles. I've been sporadically tracking kappa on my 2014 i3 Rex (with ~76000 miles) since December 2021, as I'm considering the optimal time to bring my car in for a battery check. In California, we have 10 years to do this, and I'm waiting as long as I can to give me the best chance of the battery failing the test. Here's the data I've collected. Please excuse the formatting.

Date Kappa % of 18.8 % charge when measured
12/16/2021 12.1 64.4%
1/11/2022 12.5 66.5%
1/15/2022 12.5 66.5% 14%
1/18/2022 12.1 64.4% 100%
1/25/2022 12.0 63.8% 49%
1/27/2022 12.0 63.8% 12%
2/3/2022 12.3 65.4% 62%
3/2/2022 12.2 64.9% 100%
3/8/2022 12.1 64.4% 58%
3/23/2022 12.9 68.6% 40%
4/5/2022 12.9 68.6% 25%
4/12/2022 13.1 69.7% 100%
4/27/2022 13.0 69.1% 24%
5/19/2022 13.0 69.1% 26%
7/11/2022 12.3 65.4% 100%
8/20/2022 13.8 73.4% 12%
9/2/2022 12.5 66.5% 20%
10/27/2022 12.6 67.0% 19%
11/20/2022 12.1 64.4% 14%
12/19/2022 12.0 63.8% 27%

Basically I'm going to wait until about 6 months before the 10 years are up and then get serious about bringing it in.

I'm looking for comments, questions etc. regarding a good strategy to follow up with as what's the best way to give me better odds of having a module or battery replaced.

TIA

[alohart]

Consider that batteries degrade just by being batteries. They're like kids: they can be coddled, but that won't stop them from aging. Even if they've been perfectly cared for...

Amen! The battery pack in our very coddled 2014 BEV lost ~25% of its capacity despite having been driven only ~13k miles over 7.5 years. Meanwhile, many other 60 Ah battery packs don't seem to be degrading nearly as rapidly. Maybe the quality control of 60 Ah battery cells wasn't as good as that of 94 Ah and 120 Ah battery cells. Seems a little bit like the luck of the draw with 60 Ah battery packs.

[alohart]

For example, if you set a Departure Time of 9am and choose "Precondition", the car will measure the ambient air temp for awhile and keep track of the temperature of the battery pack. If the pack falls below 50F, the car will come on 3 hours in advance (in this case, 6am) and will circulate warmed coolant around the battery pack until it reaches 50F.

Our 2014 BEV didn't have the heated seat and battery pack option (not needed in our tropical climate), but it did have a heat pump. Supposedly, I would not have been able to precondition (warm) the battery cells because there were no electrical resistance heater wires below the them. However, the heat pump would have allowed me to precondition (cool) the battery cells. So I think that preconditioning (warming) the battery cells is done with resistance heating and not with the refrigerant that cools the battery cells. The refrigerant plumbing schematic doesn't indicate an obvious way to precondition (warm) both the battery pack and cabin simultaneously, and BMW's TIS Website doesn't describe preconditioning (warming) the battery cells with refrigerant, only with electrical resistance wires.

That said, a Norwegian i3 BEV owner swears that the A/C compressor turns on during preconditioning (warming) his battery pack. One explanation could be that the compressor is running so the heat pump can precondition (warm) the passenger cabin while the electric resistance wires are warming the battery cells.

[alpine788]

TRUE DAT E NATE!

[partialteen]

For example, if you set a Departure Time of 9am and choose "Precondition", the car will measure the ambient air temp for awhile and keep track of the temperature of the battery pack. If the pack falls below 50F, the car will come on 3 hours in advance (in this case, 6am) and will circulate warmed coolant around the battery pack until it reaches 50F.

Our 2014 BEV didn't have the heated seat and battery pack option (not needed in our tropical climate), but it did have a heat pump. Supposedly, I would not have been able to precondition (warm) the battery cells because there were no electrical resistance heater wires below the them. However, the heat pump would have allowed me to precondition (cool) the battery cells. So I think that preconditioning (warming) the battery cells is done with resistance heating and not with the refrigerant that cools the battery cells. The refrigerant plumbing schematic doesn't indicate an obvious way to precondition (warm) both the battery pack and cabin simultaneously, and BMW's TIS Website doesn't describe preconditioning (warming) the battery cells with refrigerant, only with electrical resistance wires.

That said, a Norwegian i3 BEV owner swears that the A/C compressor turns on during preconditioning (warming) his battery pack. One explanation could be that the compressor is running so the heat pump can precondition (warm) the passenger cabin while the electric resistance wires are warming the battery cells.

Thank you for sharing your understanding. It is really helpful for me.
redactle