Help Please - hybrid battery acting strange!!

Assuming the 10 years or 150K mile warranty in a CARB state has expired... It is 2018 after all...

First thing I'd do is take apart and deep clean the car, get as much info about it's history from previous owner as possible, upgrade the 12volt battery with 55 amp hour back up power supply / wheel chair battery from Batteries plus for $130 and clean the hybrid battery cooling fan.

I'd then use OBD2 reader and various phone apps to get battery data, then finally get my Toyota techstream software running on my computer to get more battery data while I get someone else to drive, preferably on a really long road trip...

Then once I have a sense of the car's overall performance with MPGs, etc. pull the pack out of the car and remove the bus bars and get voltage data, resistance data and load test data on each individual module.

Then I'd do three or four discharges and recharges of each individual module and get more data from how well each module does and how it's improved as each discharge is a deeper and deeper of a drain down on voltage, which re-activates all the stagnant electrolytes by breaking up bad conducting larger crystallization into better conducting smaller crystallization. (Read articles about NiMH battery maintenance science to learn more).

I also use a laser pointer thermometer to get temperature readings of each cell in each module to see if any of them are too hot or too cold during discharge and recharge.

Once the pack of modules is fully charged and ready to go I let it sit for a few days to let it self-discharge and get more voltage data. All this data is put into a spread sheet for future diagnostic use... It helps me plan for which, if any, module needs to be replaced next. For best results replacing the weakest module before it goes bad is easier on the overall pack in the long run.

Next step is cleaning off all the corrosion and caustic residue, then putting in brand new bus bars and new nuts and putting the pack back in the car and installing a Prolong discharge ready harness for future use when data indicates declining performance and don't have time to pull the whole pack and do individual modules again....

This summary of work is still evolving as I learn more every time I work on one and there's loads of specific equipment I purchase, as well as build myself to do this work that is not mentioned in order to be brief.

 

That's a very big laundry list of things to do.

A normal consumer probably won't have the time or the skills to do what you're doing. They would wait until the battery dies (out of warranty) and then hopefully find someone to sell them a slightly used battery for $1500 and continue driving for many more trouble free/maintenance free years.

A prolong system will already set you back $700 and you'll have to keep balancing the battery in "hopes" it won't die on you. You're bringing a DIY solution to a known problem. If you have an engine failure, the DIY guy will be able to put in a new engine for $200. It's not something that everyone can do.

 

Yes, also heat, in that darker cars in hotter climates the pack degrade faster. Also driving habits that minimize the stress place on the battery pack, which is why when Toyota had to provide 150K mile warranty in CARB states they disabled the stealth mode that allows you to use all electric and no engine for brief periods under certain conditions by pulling back your windshield wiper controller for 2 seconds. Also a Prius owner who lives at the top of a hill is going to park the car at home with a far more discharged pack than a Prius owner who recharges in the last stretch on the way home going down a long hill.

Most of all the basic fact that any text book/website about NiMH battery science explains that battery re-conditioning is essential for this type of battery. Too often on PriusChat we refer to a battery pack in need of routine maintenance/reconditioning as a pack that is dying is going to fail. But that's not what the science says, it's what Toyota say to remain profitable.

 

It may seem like a long a list, but it's really not... If I made a list of everything you had to do to replace a head gasket it would be much, much longer....

When I first started learning to do this I would of agreed with you. It took me two days to do a single discharge/recharge and data gathering. Then it only took 8 hours and next time thanks to some equipment I'm building it will only take 4 hours, then even less time. The more I learn the more efficient and streamlined the process gets.

All this could of been designed into the car very easily had Toyota been forced by CARB states to do so. But capitalism is more interested in you only loving your car long enough to want to buy a new one, not maximizing the lifespan of the old one.

 

This science is what keeps Prolong profitable. $700 for a system that needs routine maintenance, or buy a slightly used battery $1500 and be worry free for many years.

I think most consumers would prefer the unscientific route and leave the science to scientists and Toyota

 

I bought a used Prolong charger and light bulb discharger from a mechanic for $200 and the $160 wiring harness was a back up plan for hyrbid battery I repaired for a friend with not much money who was pleased to see me deduct labor charges in trade for the harness we didn't use. So some people might pay $700, some people might pay much less.

 

I'm all for rebuilding/reconditioning the battery. Hey I'm one up on you, I didn't even buy my charger. I built my own to use on my fleet of Prius cars.

But it's not for everybody. And without spending money on tools, equipment, etc, you won't be able to make the Prius battery last any longer. It's like a 12v battery. Some will last 4 years, some will last 8 years. But it will eventually fail.

 

Agreed... But intention is everything... And currently there's loads of Prius owner that can't afford a new stack of modules and the more I can help them do what they can afford the better. The biggest problem is that spending a few hundred bucks before anything is broken is a tough sell. But that what I'm practicing by doing all these writings. Trying to refine the message...

 

The message you started many posts ago stated there is a preventive method to make the battery last longer. Without mention of tools or equipment costs. After understanding your message, it requires pretty much a Prolong set up.

These options have been passed around here.

1. Rebuid with Prolong for $700
2. Buy refurbished by unknown rebuilder $800
3. Buy slightly used good modules $1500
4. Buy new $2000-$3000

Priuschat regulars often say don't go the refurbished route because many people are out for the quick buck and doing modules swaps for $25 and then reselling the battery for $800. I don't think there are much negative comments on options 1,3, and 4.

 

Yes, option 4 is currently a rapidly lowering price point and is close enough to option 3 to finally be competitive... Option 1 can be done in less expensive, though time consuming ways and if Prolong sales growth increased and they had a competitor I'm sure they'd be dropping prices in big ways. Option 1 is what I'm most interested in working on.

 

You are answering the question you wish was asked, not the question that was asked.

The answer to the question asked probably goes like this.

Nothing. Toyota designed the HV (Hybrid Vehicle) battery to be maintenance free. There is no maintenance schedule so there is no requirement for the owner to do anything as far as maintenance goes.

Now, how’s my popcorn? Umm, a bit low. Brb.

 

It was originally designed in the first generation Prius ...

... but removed in the next generation onwards. Why? Not for the above conspiracy/paranoia theory, but Toyota found the cost/benefit did not justify it. So, yes it was for economics. To save money for the customer, not to feather the Toyota corporate nest.

JC gives a good example here. Plenty of posts here on PC show the a lot of owners have neither the knowledge nor the inclination to get the best out of their 12 V battery. They’d much rather throw it out and replace it than spend money on a charger and 5-10 min of time once or twice a month to use it.