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Old 10-04-2022, 12:47 AM   #3 (permalink)
S Keith
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Originally Posted by broski499 View Post

I'm at a crossroads. My 2008 Prius is approaching 107,000 miles. MPG has really dropped in recent years. My commute is shorter, but I think it also has to do with the battery aging.

I've been using DrPrius to monitor the pack and I've done the lifespan test a few times as well.

Dr. Prius reports that the Battery pack is running hot. Bottom voltage is also problem on block 5,6,7.

On my two life expectancy tests I got a 20% and a 36%.

When I step on the brakes and the regen kicks in the pack voltage shoots up pretty high, 260+, and turns red. Individual battery blocks also turn yellow and red.

Internal resistance varies but I have quite a few a 30. At what point am I going to see a pack fail.

I'm trying to decide if I want to trade in the car now and get a Volt or a Leaf. I'd rather the $1500 I would use towards a battery pack for the prius could just go towards a new car.

How can I tell if my pack is on the brink or just on the lower end. Are the grid chargers worth looking into or is a battery pack replacement more economical. Thanks.
Years-long mileage drop is more often caused by a change in operating scenarios. Shorter trips are devastating. Heat can be devastating.

My son has a 2008, and he averages 32 mpg. He drives 6 miles to the light rail station and 1.5 miles to work. My daughter drives a similar pattern, but she gets 34mpg (lighter foot). I drive a more typical city/hwy blend and get 39mpg due to a lead foot. My wife drives a commuter profile and tends to average 42-44mpg with a moderate foot.

Your mileage log looks really erratic.

In my experience with a few hundred gen2, batteries tend to fail when pack capacity deteriorates below 40%.

If you catch them before they drop a cell, a grid charger/reconditioning system can often restore them to 85%+ depending on the nature of the degradation (if you had a Gen3, you'd be out of luck - when they fail, the completely crap the bed).

Here's a little something I wrote up before I got banned from PC:

Images are gone, but the relevant results are in the table.. 27% health to 90%.

That one reconditioning cycle lasted over 3 years before the battery failed (I'm still good friends with the owner).

107K and considering replacing? I can't wrap my head around that. A low mileage Prius to me is 150K. You're sitting on a car with another 140K+miles.

G2 prius is a 250K mile platform with a few major maintenance events: 3 inverter coolant pumps, HV battery, ABS actuator, and a combination meter (in order of likelihood).

Even if all of the above happened, you'd still be sitting pretty good on the total outlay for a car with another 140K miles in it.
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