Winter ev range in 2018 Prius phv

Yep, that's completely normal. My top summer EV range was ~40miles with ~35 miles average. Now with heat on, I am lucky if I get 20 miles from a full charge. I account for ~50% reduction in EV range from the best to the worst.

 

Welcome!

That's very normal. Yes, a 12V that's failing would also reduce your range a little, but that only takes a couple minutes to check. Loss of a third of your range in winter is pretty typical up north.

If the 12V is the reason for trouble getting in the car, you'll also note that the brake pump runs longer than normal when you open the driver's door. But if it's that low, the car normally gives a warning message on the dash. Details about the trouble entering the car might help in chasing that down.

 

How many miles each day did you drive? If the sudden drop in the EV range was a recent event (within the past 32 days), then you may still have the precise record of the miles driven each day and with what efficiency. It is quite possible to have a large decrease in the displayed EV range overnight if your daily drive was very short with very high efficiency in a range of 5-6miles/kWh and a day or two days prior to the drop you did a long drive which depleted the EV range with very low efficiency less than 3miles/kWh.

Also, if your EV miles are based on the actual miles driven per full charge not from the displayed EV range aka GOM (Guess-O-Meter) when the traction battery is full, then the drop is more gradual than the displayed EV range. The GOM swings down rather quickly after one very bad day, but it does not climb up quickly even with a stretch of days with better efficiency. Those records are all in the Eco Diary, if you manage to look at it before it gets erased.

 

Just listen when you open the driver's door in the morning or any time the car has been sitting unused for several hours. If the 12V is low you'll hear it running for a long time when you open the door. When the 12v is healthy, it takes about 3-5 seconds to stop whirring.

 

Yeah, with no change in driving routine, the drop in EV range both displayed on GOM and actual is more gradual over say a week or two depending on the change in weather. As already suggested, it may be worth checking your 12v battery. I can't think of the reason that a bad 12v battery directly affects the EV range, but when the 12v battery is weak or dying, all sorts of weird things happen to PP. A simple voltage check may not be enough. If you have access to a battery load tester, that will give more solid information about the state of the health of the 12v battery.

 

If the 12V is low and the DC/DC converter is constantly feeding amps to it to try to get it up to nominal voltage, that is extra load on the traction battery and will reduce the range.

Sarah's range reduction is pretty significant, but the door entry issue plus the range issue would take me straight to the 12V battery first thing.