HV battery

I would use a multimeter and check every module individually. Replace the ones with the biggest difference

 

While that sounds logical........there should be some lower limit where they don't NEED to be replaced until they go that low.

And I am of the opinion that when you have to replace the second one, you should do them ALL. That is if you are doing it yourself.

Most of the reports here indicated that it isn't worth your time and money to buy a rebuilt battery because it is likely to fail again soon if only the bad cells are replaced.

 

well done o/p!

 

Take the "30% capacity" with a grain of salt. The "Dr. Prius" app is not really that scientific. It can show good data, but it is easy wrong and manipulated. So, good data point but not gospel.

Your pack shows the classic signs of heat death. The middle of the pack, where the heat gets stuck, is degraded far worse than the outsides of the pack. This is the most common and most classic case of a bad battery.

500mV of difference between the highest and lowest while not good, is far from the worst it can be. You may be able to extend that pack with a Prolong type system. I don't think it is too far gone for that to be of help.

And you are correct, if you go with a whack-a-mole solution or a rebuild pack, you'll be back. New pack is the correct long term answer. If the car drives fine now, I would use this time to think about what you want to do.

If you want to trade in the car do so in the next few months. If you want to keep the car, then for how long? If you want to keep it for another decade then buy a new battery. If you want to keep it for a year or two and you have infinite time (retiree that loves working on cars for example) then playing whack-a-mole may work for you.

 

hybrid automotive.com

 

Yes, lower fan on temp on Dr Prius.

 

You have a dead HV pack. I don't understand why you're surprised things don't look good and you're getting errors...

If your goal is a temporary quick fix or your time is worth $0/hr, then go ahead and change out the 2 battery modules and balance everything up. You'll be back in there before Spring starts but the car will be back on the road. It's all tradeoffs. I personally hate doing repairs of the same thing over and over again, but I also value my time very highly.

You can balance with a lightbulb and a multimeter if you have the skills, time/patience, and ability. Lightbulb as current limit to charge and as a discharge. This is not recommended especially if this is your first rodeo. There exist cheaper NiMH chargers made mostly for remote controlled vehicles and you can generally do one battery module at a time (6 cells in series). Assuming it takes about 8 hours to do a couple charge and discharge cycles (which is what balancing partly is) that's 224 hours of work from a single charger. Over 9 days if you have them going 24 hours a day and will babysit it every 8 hours-ish to swap the next module. One of the reasons why if you go cheap, it is recommend to buy multiple cheap chargers. Now you've spent $200 for a lot of manual labour that will buy you a few months.

If you're keeping the car, that is just completely wasted money when you buy a real brand new battery.

 

you can probably resuscitate it with a model charger

 

prolong would do the entire battery at once. a model charger does one module at a time iirc. they are priced accordingly

 

I’d argue the model charger is more expensive if you factor time and money into the equation .

That’s why I invested in the Prolong equipment .

 

And I would "argue" that if you think you can materially affect individual cells properly by doing anything to the whole battery, you are just fooling yourself. By that, I mean "rejuvenating" an individual cell without connecting directly to only that cell.

 

i won't argue with anything cause i know nothing but what i read here

 

If you are only keeping the car for several months, I would replace the affected modules and hope for the best. Why bother with the reconditioning?