Battery range continues to drop when Rex cuts in.

[cksky]

Hi my Rex cut in 10 miles from home at 7% battery, 7 miles range while doing 40-60 mph. The battery continued to drop to 3% and 3 miles electric range before slowly building back up a bit. Is this normal? I was getting worried that it wasn't doing anything.
Also when I got home and locked the car it sounded like the Rex continued to run, is that normal?
Thanks.

 

[FrozenRex]

This behavior is very similar to what I have observed (3.5 years ownership). The Rex takes several minutes to warm up before it can reach full output. During that time the miles remaining will drop depending on electrical load. In the frozen north I frequently see it drop to 3 or 4 before slowly recovering to 6.5 which might take 15 to 20 miles of driving. It sounds like you reached home before full recovery occurred.

A noisy cooling fan for the Rex will continue to run for 5 minutes or so after you shut down under these conditions. Normally there is also a warning notice to charge immediately to avoid battery damage on the screen.

 

[SuperPoly]

I would strongly recommend coding "hold state of charge" which adds an option to start the REx as low as 75% state of charge.

Non-US i3s all have this option by default.

 

[cksky]

Ok thanks, sounds normal then. Yes It was cold weather. I didn't see the message but I put straight on charge anyway.

I didn't intend to use the Rex but the GOM electric range was reduced on the return journey in the cold and caught me out. I was nearly home otherwise I would have held the charge as it's a UK car. I have not long had it so still getting use to it, was reassuring to have and try the Rex. Next time I won't wait for the Rex to auto cut in but hold charge sooner.