Range

[sezhiana]

Hi,
I have a 2017 94 BEV @ 77K miles.
I drive about 42 miles, round trip, each day to work.
When I start @100% charge, it takes about 27%, in summer, for that distance, with more than 50% on highway @ 70 mph and a steep hill. I charge each day at home. However, if charging failed, which is a different story, then I start at 73% and this time the vehicle uses about 33% of charge for the same route. Does anybody know why this happens?

The problem with charging is that when I plugin, the vehicle starts charging, but on occasion, few times a month, it stops after a few minutes and it blinks red. I only notice it int he morning. For most days, it charges without any issues. What could cause this?

 

[EvanstonI3]

Could be fault with your ESVE (charger)
Could be fault with your electric supply (voltage varying enough to make the thing shut off)
Could be that it is too hot to charge. What is the ambient temperature where you are?

 

[eNate]

I can't offer a suggestion for your charging problem. You'll need to do some troubleshooting using an alternate EVSE and perhaps find the trouble codes to interpret what sort of condition the flashing red light indicates.

As for the state of charge, there are a couple of things.

First I assume you're charging to 100%. What I've noticed with my i3s -- both of them, a 2017 followed by a 2021 -- is that when topped off, the battery is actually hiding a little more energy than indicated. In other words, when I leave work at 100%, I can make it about 2.5 miles before my battery indication drops a half point to 99.5%. But when I leave work at 80%, I lose that half point in less than a quarter of that distance, and I'll be 2% down by the time I reach the 2.5 mark I noted in the 100% example.

Secondly, battery state of charge calculations are not a precise science. They're relying on measuring resting voltage and converting it into a percentage, and voltage doesn't decrease on a perfectly linear scale. So there's always a "best guess" component thrown in.

Another factor could be that the fully charged battery is carrying more latent heat from charging and is therefore operating more efficiently, which could be reflected in the %SOC calculation vs. the "cold" battery that sat all night.

 

[Dutchi3]

If you use the charging cable that came with the car, it may be that the cable has some loose internal connection now and then. In that case, when you fiddle with the cable, it starts charging again. That could be a sign to replace the charging cable.

 

[Egbert]

First I assume you're charging to 100%. What I've noticed with my i3s -- both of them, a 2017 followed by a 2021 -- is that when topped off, the battery is actually hiding a little more energy than indicated. In other words, when I leave work at 100%, I can make it about 2.5 miles before my battery indication drops a half point to 99.5%. But when I leave work at 80%, I lose that half point in less than a quarter of that distance, and I'll be 2% down by the time I reach the 2.5 mark I noted in the 100% example.

I notice the exact same thing on my 2018 BEV. I also think the last 25% seems to go slightly faster than the middle/upper 25%, but I rarely get down that low, so it's hard to know for sure.

As to charging errors- I'd start simple. Look at the condition of your charge port connections on the car and your cable. Do you have a place nearby that has free or low-cost Level2 charging? If so, maybe you could try to stop there and charge for a bit several times and see if it ever fails. That might clue you into a problem with your EVSE.

 

[sezhiana]

Thanks eNate, for the explanation.
This is not the charging cable that came with the car. Previous owner seems to have bought it elsewhere. The cable has been replaced by the vendor once. I will check with the Level 2 charger, as suggested.
Thanks.