Hybrid Battery Replacement???

12.4 volts seems low to me. Not sure if that would have any effect on fuel mileage though.

 

Depends if it’s 12.4v over night or right when car was turned completely off and not limited to those 2 instances.

There was one person here that resolved a similar issue just by replacing the 12v with a great working one but that was the only success that I know of here.

 

12.7 to 13.2 volts for a fully charged battery. 12.4 volts is at about 75%.

 

Use a different type of car wash. The Prius does not charge the traction battery when in neutral.

 

Those cells voltage maybe out of balance with the rest of the pack, and hope that their ability to hold charge with the rest is the case after the battery pack is serviced with a grid charger. It's been fully discussed in here to avoid putting a prius gear in neutral because the HV doesn't get charged, some car washes that requires car to be in neutral will even post a sign to not allow prius to enter car wash. Prodigyplace is right, avoid car washes that requires your car to be in neutral. Some prius owners are able to get away with it by going into those car wash with a fully charge HV battery but once summer rolls around, they'll turn on the AC and evenutally run into check hybrid battery CELs.

 

Your pack is dying a slow and somewhat natural death. My guess is the heat stress from the low flow of air due to the dirty fan put a few more nails in the coffin than most 2010 packs.

You should look into grid chargers vs getting new modules vs how long you intend to keep the car, etc.

GOOD LUCK!

 

Remeasure, but waiting after overnight and measure at engine bay designated recharging points keeping correct polarity w/no load. Readings higher than 12.7v is best.

Dr prius app is my favorite app with the prius HV battery. A .3v difference isn't bad, there's a section on the app that show voltage difference between the lowest voltage charging pack vs highest in real time. While driving, my voltage difference stays relatively within .2v and spikes to .3v once in a while so your in good shape. Another great feature is the fan override, once the ambient intake temp is cooler than the battery pack temp (both on the app display), turn up the HV cooling fan (in the settings section) to pull the colder air in the cabin into the battery pack.

 

You're at the end of the expected life of the battery. It's not about the mileage it all about the age of the battery. It seems about 9-11 years is the average, some sooner, some later.

With your mileage which is over 200K I would go with a rebuild kit and do it yourself. One of our members sells a quality kit for a very reasonable cost.

Mine started to do the same thing, discharging and recharging quicker and quicker. The code you got is just telling you that the battery is dying and replacement is near.

The code that said my HV battery was deteriorating started to pop up randomly. I got another nine months out of it before I got the dreaded you battery is terminal code.

 

The rebuild kit of new cells from @2k1Toaster here is $1600 delivered. The link is in my signature. People here have had good, like new results from this kit. It has a 2 year warranty. If you buy a Toyota OEM battery and install it yourself, it only has a 1 year warranty.

 

It will be interesting to see how well this holds up. Other than @2k1Toaster kit the only other non-Toyota new option we knew of did not test up to their stated specifications.

 

You replaced the hv battery that was NiMH with lithium components ?

Have you cleaned the egr circuit stem to stern?

I’d go after that next.

Good luck and keep us posted .

 

... and reprogrammed all the battery -- management software accordingly?

 

If GT really told you they installed a lithium battery in your car, you got yanked...............and I would love to see a photo of the serial numbers on the modules so we can verify what definition they use for "brand new".....

I wonder if they're using "brand new" prismatics or if they're using the chinese cylindricals? They don't seem to mention that. The more I think about it, at $1850 + $750 core, I'm thinking they're using the chinese cylindricals. We need PHOTOS........

 

Here is the page. They claim greater capacity too.
Wouldn’t the ECU need to be reprogrammed for that too? Charging capacity would be different.
Gen 3 Prius Battery Replacement WITH NEW CELLS | Greentec Auto