Should my Hyb. batteries be dead at 68,000mi?

[2009Prius]

Originally Posted by Shawn Clark

Floyd,

This is more a matter of perspective: You won the hybrid lotto! Unlike most owners, you have a brand new hybrid battery, paid for at Toyota's expense in a 4 year old car that is otherwise approaching the end of the hybrid warranty (32,000 miles left to go.) About the only thing better would be having it go at 99,999 miles and 7 years + 364 days (non-CA warranty.) The worst case is having a battery fail at 100,001 miles or 8 years + 1 day.

Yes, it dents your confidence in the reliability of the car but assuming there isn't a nasty gremlin in this particular sample of the vehicle you are set. Toyota warrants the original batteries for 100,000 miles so another short life failure would be highly unusual.

Personally I won't mind another short life failure right at 99,999 miles and 7 years + 364 days.

[Floyd]

2nd update: I apologize; I'll probably trade for another Prius in 2011. Really, I wouldn't take a gold monkey for my car.

Luckily, I have another car that I use as standby. The dealer kept the car a week mainly because they had to get the battery shipped, plus, one day the Prius tech. had to go to school.

While in the shop, I got a new 12v battery installed. With the new Hyb battery, I seem to be getting better mileage. Before, I was getting 44 to 45mpg. Now my screen indication is around 50mpg. I can get into the ev mode easily whereas before, it was a real effort. I'm just wondering if the old battery was maybe defective from the get-go or was never quite up to par, maybe a weak cell that prevented top performance. (no doubt, going bad at 68,000mi)

Now, it seems like a different car and I'm a happy camper. Thanks for all the replies.

[ggcc]

Originally Posted by Floyd

2nd update: I apologize; I'll probably trade for another Prius in 2011. Really, I wouldn't take a gold monkey for my car.

Luckily, I have another car that I use as standby. The dealer kept the car a week mainly because they had to get the battery shipped, plus, one day the Prius tech. had to go to school.

While in the shop, I got a new 12v battery installed. With the new Hyb battery, I seem to be getting better mileage. Before, I was getting 44 to 45mpg. Now my screen indication is around 50mpg. I can get into the ev mode easily whereas before, it was a real effort. I'm just wondering if the old battery was maybe defective from the get-go or was never quite up to par, maybe a weak cell that prevented top performance. (no doubt, going bad at 68,000mi)

Now, it seems like a different car and I'm a happy camper. Thanks for all the replies.

Floyd,
How do you get to EV mode? Do you install EV switch on your Prius?

[Floyd]

Originally Posted by ggcc

Floyd,
How do you get to EV mode? Do you install EV switch on your Prius?

I may not have the right terminology. EV mode to me is when I can drive under battery power only. Usually lightly accelerate from a stop or coasting (when the engine cuts off) and under 39mph. I haven't noticed how many charge bars I have when I do this but the new traction battery seems to retain a charge better therefore making it easier to go under battery power only. Usually, I can't go very far this way only about a mile. I think some others on the forum have gone further.
I haven't installed the EV switch mainly because of my wife. Bless her heart, she may leave it on accidentally, and u know the rest of the story.

Bottom line: I'm sure there has been several Prius's that came off the production with a defect in the traction battery (Hyb. battery) whether a weak cell or what ever, that would cause sub-par performance.

[DaveinOlyWA]

Floyd;
thanks for the update. very interesting the change in MPG's being so dramatic. did you by chance track each tank's performance??

if so, i strongly suggest you starting a thread showing the mileage performance before and after the battery change. might be of interest to the many people here who are not getting the mileage they had hoped for

[Shawn Clark]

Yes, this could be a key point for some: What happens if the hybrid battery is "weak" from the outset? Does mpg suffer noticeably?

It makes sense that if the original battery was marginal (e.g. a weak cell or two), the pack would fail sooner. What is not as clear is how this might impact overall gas mileage.

[Floyd]

Originally Posted by Shawn Clark

Yes, this could be a key point for some: What happens if the hybrid battery is "weak" from the outset? Does mpg suffer noticeably?

It makes sense that if the original battery was marginal (e.g. a weak cell or two), the pack would fail sooner. What is not as clear is how this might impact overall gas mileage.

Driving for a while after the Hyb battery replacement, I have noticed an increase on the MFD only and haven't refueled enough yet to get consistent tank mileage but will post another link later after I have cycled thorough a few tanks.
I talked to the service rep and asked if they did anything besides just replacing the Hyb battery & he said that was all they did. The mpg increase may just be unusual but around 50mpg is the overall average of interstate travel about 20miles each way that I'm getting now. Before, it was between 43 and 46. As a matter of fact, we took a round trip of 600 miles the day before the battery went belly up and the last tank averaged only 38mpg. I thought something was unusual and passed it off as an uncomplete fuel top off the tank before the last one.

U know how it is when filling and different gas stations, its a little inconsistent. Looking back, I attributed the low mileage to the engine constantly having to recharge the battery. I may be all wrong, but it's looking that way. I'll get back later to post my findings. Thanks

[drees]

Right on - with a weak battery that rapidly loses charge, the Prius isn't able to use the battery's stored energy under certain conditions (gentle starts, cruising at low speeds) to improve fuel economy and as a result the engine ends up running more.