Loses power "without warning"; actually, when the REX turns on it automatically mentions that power "could be" lost when the REX turns on. However, that is very understated. In fact, there is nowhere in the owner's manual that raises this issue; doesn't even mention that there could or would be a "warning" if battery is low and REX is being used. Bottom line: The REX cannot keep up with driving. Please refer to: https://www.youtube.com/watch"v=hmn58reGv8k The above is identical to my experience. Especially VERY DANGEROUS when on the interstate highway. I was looking for an exit so that the battery might recharge a bit because I could only go 25-35 mph. Seems like the REX is warming up and not outputting standard power, as expected... It might be that the problem is that the computer is not calculating the correct state of charge and therefore not giving the REX enough time to complete its warm-up cycle." Or it should kick in earlier than single digit battery strength left. I started recording at 9% SoC and I was expecting this power loss. I found a safe(r) road to do this on with minimal traffic. Fast Forward to 2:59 to see the power-loss happen. The first time this happened I was on the highway, that was not fun. To quote another driver with the same issue (see YouTube earlier), "Power-loss due to low charge should be gradual and with a warning, not this sudden. This makes for a dangerous situation if I'm on the highway or hill. I know that enabling 'hold state of charge' before 7.5% is a 'manual workaround' but that is NOT a fix. HSOC is not even an option on the REX in the USA - you have to unhide the menu via a coding change."

- Auburn, CA, USA

Started the car after charging it overnight and "drivetrain: Stop carefully" and "transmission malfunction" appeared on the dashboard. The car has been completely fine before this.

- Acworth, GA, USA