HV battery condition ?

Hi all!

3 years ago i bought a 2008 prius with 130k miles on, previous owner said toyota insisted HV battery need replace. 12v battery was also impossible to keep charged and dash/inst pnl lights went out all the time.
I got the car home found rear defrost malfunction, pulled the fuse for it. Cleaned all the hv battery terminals in vinegar and dash light problem solved by other 2 problems fixed and keeping battery chargers away from car. (That triggers dash light problem)

The car has been used for the past 3 years and now has 150k miles. Weve not had any problems with it at all, just runs perfect no warning lights, most trouble free car weve ever had.

So why post here?? Well, believing toyota and knowing nimh batteries wont last forever, i bought a complete untouched battery the other day of 74kmiles 2010. Before swapping modules i thought id get a picture of the original battery performance so i could do a before and after. The results surprised me so much i wondering if i should leave it alone. I would appreciate anyones experienced opinion on this.

Heres a photo of battery under heavy acceleration load.

 

And no load

 

Heavy load again

 

Regen braking.

 

I tried the pid for internal resistance of each, they just read 0.
So i did the math and the internal resistance calculates at or near .323 ohms for the total series resistance of the pack. I tried to look it up and toyota spec is .5 ohms for total series resistance when they are new.

I guess i feel like i could get a worse battery than this one by doing just about anything, much less swapping in a set of used cells. Since my replacements are a full set just taken from a running car it would eliminate much of the balance hastle or worry that id get a bad module but could i expect better performance than this from a 2010 gen3 pack at 74k?

Any thoughts from experience on this would be awesome!! Thank You all for your great contributions to this forum!!

Canary

 

why are you thinking of changing it?

Hi! because of many threads here that say "if your battery is over 10yrs and 150k miles pony up the money to buy a new one" and my Lady is the one who drives this car and i dont want it to fail on her. Reason 3, Toyota condemned it 3 yrs ago, their decision had to been based on something.
Honestly i figured we were running on borrowed time and failure was just around the corner but now after looking at performance i seem to have been wrong.

 

Great info! I will do those things and report back.

Yes i guess 10 yrs is a long time and variables could add or subtract a few yrs. As far as toyota writeup i dont know either but somehow convinced previous owner to buy new car from them, surprised they didnt even trade, I got the car for 1K plus 1K shipping. It had the 12v converter so loaded down it couldnt even run the basics without a fully charged battery, it would kill battery in 2 minutes. Once those issues were corrected it been a fine car since.

 

Initially, i pulled every fuse that wasnt related to the necessary engine and controls. Then i added back one by one, the last i plugged in was the audio system, was sure thered be a problem there but nope. Rear defrost is the only one i eliminated so im guessing that was it. Seems strange a rear defrost could use so much power. The guy who delivered it said it killed his jump pack just loading it on the trailer. Still baffles me because the problem was gone and never came back. At the time i was unfamiliar with the prius design and wasnt about to poke the bear when all went to normal. The SKS does drain the 12v if it sits for more than a week, not fataly but volts are down in the 12.3 area where it hurts batteries. I did however notice the other day my konwei bluetooth dongle was drawing probably more than the sks so i unplugged it and tossed in glove box