EV Mode Usage

It can. You generally want to minimize the large level cycling of the HV battery. Try to only use EV for short periods of low power demand, such as parking lots, moving in/out of the garage, rolling slowly down a residential street, etc. Try not to use it for climbing hills or accelerating quickly.

 

If you are interested in pro longing the life of your traction battery you will be better off if you pulse and glide rather than EV. When gliding you are using no power other than momentum. The traction battery has a limited amount of charge and discharge cycles. The less you use it the longer it should last.

YMMV

 

I installed an EV switch in my 08 when it had 140k. I used to think it was smart to drain my batteries in the last mile, park, then let it charge up in the morning since the ICE runs in the mornings at first startup anyway. To my dismay I learned that this caused a daily deep cycle as the AC runs hard at first use. Then it would start running dead in car washes because I was in neutral. This did not happen previously, so my charge cycles were evidently shorter from my morning abuse. I soon could no longer run the last mile home on EV. It barely lasted 1/2mile. Then it would go from full charge to dead each morning eventhough I did not use EV coming home. Within 10k miles I killed this battery.

Prior to this mistake I used, and still use my prius to tow a trailer with a bike or two on it. The trailer has a large gate which causes so much wind dray my max speed is 78mph on the flats. Combines weight is 1k lbs or 1600lbs, depending. I run it at full throttle for 10h trips, stopping every 2 hours to refill the tank. The car gets no relief in 98F weather. My trailer tires pop from the heat, but the car has no issues except a dead Cat which is not totally atypical for these cars. I only add a qt of 5-40 every 5k. If towing at full throttle I add a qt every 2k. Not a surprise. It's 5k rpms and full power, tank after tank. No joke, I really hold the throttle all the way open for hours in 98f weather pulling a trailer at 78mph.

Summary: I can run the car at full power all day long with a trailer and kill only the Cat, but hammer the traction battery with overuse of the EV mode and the battery is a goner.

 

Thanks for the cautionary tale Doug. When I first got my Prius I tried to use the EV button a lot also. I think I was lucky enough to realize it was bad for the battery before I did too much damage. In the end I come to exactly the same conclusions as tanglefoot stated above, I now only use it for short distances in carparks and the like.

It sounds like your prius has really stood up to some hammering there. I guess that the high oil consumption caused be the sustained very high stress driving was what eventually took out the cat.

BTW. Have you had the traction battery replaced yet, and was it done under warranty?

 

My traction battery is weak at 160k miles so I bought a used one for $500. Who would want to buy my used battery for its core value?