2008 Prius Hybrid Battery
 

Greetings,

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.

I don't have experience, but I assume pack degradation to accellerate as it gets toward the bottom end because you're asking more from weak cells/banks.

In my view, trading in the car is the only ethical way to not disclose the weak battery. Selling private party is always my instinct because it maximizes the sale price. I'd have to disclose everything to potential buyers though.

Your instinct to sell sounds right to me though, unless you want to be burdened with replacing the pack.

If you can make do without replacing the vehicle for a while, even better. Fetch top dollar now for it and wait for supply chain issues to work through and prices to ease a bit.

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:

https://priuschat.com/threads/quanti...charge.160062/

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.

Yeah my mileage looks erratic because my driving between tanks can be pretty different. I can go a whole month basically doing short 4-5 mile trips for a full tank, to doing long highway stretches if we go on a trip.

It doesn't help that I didn't get LLR tires when I needed new tires a few years ago.

I know that 107k is low mileage for a Prius. I was very lucky and bought this in 2014 with only 34k miles on it.

I guess I'm trying to decide which option makes the most sense fiscally.

Option 1: Purchase and install grid charger
Option 2: Have the battery changed out
Option 3: Trade in car. Shift had offered me 6k for the car a few weeks ago, that expired and now its offering 4k. ( shift is a carvana clone )

Southern California Edison is offering 4k rebate on used EVs or Plug in Hybrids.

Does CA charge a sales tax that is offset by trade-in? That would factor into my decision. If not, I'd always sell private party.

Do you have access to charging, even a regular 120v outlet? That too would factor into my decision.

So-Cal has expensive petrol prices, so I'd be trying to buy as little of it as reasonably possible. PHEV or EV for me.

I'm not sure about the sales tax part. This is only the second car I've owned so my experience is minimal. Got 500 bucks for my 1999 camry when I bought the Prius.

I have 120 and 240, I have a gas dryer so my 240 plug goes unused. Its rated to 30 amps so I belive I can find a level 2 charger rated for 24 amps and I'll have pretty decent charging speeds.

My original plan was to find a Nissan Leaf with 10-11 battery bars under 8k but these are proving very difficult to find. Battery degradation was a real issue on earlier models.

Gas just shot up to $6 again, we were just about to make it below $5. My daily commute is super short so I could most likely get by just using electric even with a PHEV.

The used EV market is hilarious. Dealers have no idea the Leafs have degraded batteries. I'll call up once one is listed and ask for the battery bar info and they act like I'm asking a technical question. Most don't even list it in the details. 80% of the leafs in my local area have 5 or less battery bars. It's really something. They are not priced accordingly though. I've seen so many leafs with only 30 mile range listed for 10k plus.

I like the Volt but the gen 1s only seat 4. Ford C-Max Energi would be perfect, but they aren't super common.

Overnight is adequate for pretty much everything, level 2 helps when Edison plays with rates after midnight. Equalize if you have to on weekends or holidays

5.00 a gallon now seems cheap, I'm paying 6.15 for diesel

I can't even wrap my head around the $ dynamics of comparing a paid-for low mileage Prius to a new car. It's not even a choice from a financial or environmental perspective. Keep the Prius. Any money spent will get you as much or more miles/$ than a new car.

When I say new car I mean new to me. I would only be spending a few grand out of pocket when I add the value of the Prius, $4-5k, +4ksce rebate used EV or PHEV.

I’m also factoring in money saved via having pure EV range for my daily commute saving $6 a gallon gas. As well as monthly saving being in SCE prime tou plan. Lowers my overall electricity bill.

IMHO, a used BEV/PHEV is an unacceptable maintenance risk. Find out the cost to replace the battery and then determine if you're okay with that within the first 2 years of ownership.