2008 Prius Traction Battery Replacement (planning ahead just in case) - Page 5 - Fuel Economy, Hypermiling, EcoModding News and Forum

redpoint5 · 03-06-2019, 07:41 PM

Quote:

Originally Posted by Xist

I think this is the longest we have gone without discussing my crazy exes! :P

Who's crazier, the crazy, or the person that dates crazy? The pot might be calling the kettle black.

Angel And The Wolf · 03-06-2019, 07:47 PM

Quote:

Originally Posted by Xist

I think this is the longest we have gone without discussing my crazy exes! :P

Funny, they all say YOU are the crazy one!

S Keith · 03-06-2019, 09:36 PM

Quote:

Originally Posted by broski499

In this same threat, someone stated that the 2007 Prius Battery packs are predicted to start failing around now. Yeah I meant capacity. I'll double check what the app said. I'm curious as to how much this limited capacity affects the MPG I'm able to get.

What was really interesting is you are able to see the actual percentage of charge on the app versus looking at the Prius Info screen. When the app said that my battery was at 55 percent the prius info area was showing a purple battery. Doesn't look like I'm really able to access a large portion of the battery to actually use for hybrid assist.

Has anyone done a battery replacement and then seen a noticable MPG gain?

Missed this earlier.

Your perception is incorrect. It's not that the car isn't using unused capacity, it's that your battery capacity exceeds the hybrid system's capacity needs. Please remember that hybrids are 100% gas cars. Every joule of kinetic energy ultimately comes from gas. Extended EV operation in a Prius is false economy unless you have a special situation, e.g., you have a 1/2 mile flat before a large decent. You would have a net economy improvement if you could EV to the downhill and then recapture that energy in the descent... but of course, on your return trip, it would be negated by the climb.

Stated another way, every joule of electrical energy expended has to be replaced ultimately with gas energy.

To answer your question: Depends.

Was the battery severely deteriorated and had mileage been in decline? Yes.

Did the battery fail, but the car was still operational? Yes.

Did the battery have sufficient capacity, even if significantly deteriorated, to capture and release the kinetic energy required as well as perform other secondary hybrid functions? No.

I suspect you are wondering if replacing your battery would result in improved mileage. Almost certainly not unless you are in a hilly area in which the climb and descent profiles surpass the battery's available capacity. If that's the case, then you might notice a small improvement.

S Keith · 03-06-2019, 09:41 PM

Quote:

Originally Posted by roflwaffle

From what I've read it depends on what's causing the deterioration. On page 18 of this pdf, the authors differentiate between mechanical deterioration, which like you said accelerates capacity deterioration at some point, and chemical deterioration, where capacity deterioration tends to decelerate over time/cycles.

https://www.nrel.gov/docs/fy14osti/62813.pdf

First, that's a paper on Lithium chemistry. We're talking NiMH. They are nothing alike.

Second, from what I've experienced, the source of capacity loss doesn't matter. Any cause for deterioration results in accelerated deterioration.

Xringer · 03-21-2019, 06:29 PM

Thanks for the info. I downloaded Dr Prius and ordered the recommended Panlong Bluetooth OBD2 ..
The 2012 Prius C has low miles but it's getting old.. Time to start watching the battery..
I recently replaced the 12V battery. It was acting up a little..

kurzer · 03-22-2019, 04:32 AM

after 11 years and 280.000km my prius had a faulty cell. a little too soon, but it happens. i found a crashed car and bought the whole accu for some 500$. replacement via youtube with a friend in 2 hours. the good cells from the old battery are for sale now.