Replace Hybrid Battery -- Where to buy dead battery to repair?

Yes. my statement was oversimplified. While what you say seems true, evidence also suggests that niMh batteries respond well to reconditioning. And this based on the history of niMH AAA and AA batteries. There is a lot of experience with this. Some nimh batteries seem to keep getting reconditioned and continue working very long time with regular reconditioning, while some, under the same operating conditions fail to respond to reconditioning.

At the above link (site didn't allow my link yet) you can see an example of someone who tests "surging" and "freezing" to revive otherwise dead nimh batteries. Based on some experts with labs that specialized in training to repair shops on how to properly service HV batteries, they routinely revive dead cells instead of replacing them using techniques based on understanding of the actual chemistry inside the nimh batteries. It apparently has to do with the crystals that form inside the battery and surging and re-cycling techniques can rejuvenate them.

What's interesting about the site above is that the guy is "experimenting" and testing the theories about rejuvenating nimh batteries.

There is tons of interest in rejuvenating rather than replacing dead rechargeable batteries because many people are concerned about the cost of replacing EV and HEV batteries. Personally, reconditioning the battery in my daughters otherwise wonderful car every few years for $600 would be nice versus dropping $3,000 to $4,000 on a brand new battery. And prices that low of $600 with a warranty begin to make since if merely rejuvenating versus replacing "dead" cells.

Here's my idea. Most selling reconditioned batteries offer 6 months or 1 year warranty for about $800 to $1000. I will like to extend that warranty much longer for the same price but that won't be possible if it's necessary to always replace cells that begin to malfunction.

And it won't be feasible if modules in a pack truly die around the same time regardless of being reconditioned or not. So I'm looking for hard evidence of the effects of reconditioning on the chemistry of batteries.

AND I'm very keen on the new technique for testing batteries that is much quicker discovered at that university as a way to test newly designed batteries. But I want to use it to test reconditioned batteries to verify they will have longevity similar to a new battery.

 

Liability concerns while important seem far outside the scope this this thread or even this website, in my humble opinion.
I'm simply not interested in discussing my background of engineering either. I'm a humble learner here.

 

Here's an interesting discovery:

This is a list of patents that were filed and approved that are all based on excellent understanding of battery chemistry (chemistry is NOT my area of engineering expertise although I did study chemistry). I only read 2 of these patents so far, 6566844 and 20080079397. But it's most fascinating how totally "dead" batteries can be completely rejuvenated. One uses modulated harmonics signals to break up/disolve the crystals that are shorting out a dead battery. Another uses deep discharge at a high current to remove the memory effect--and the chemistry is teaching me that even niMh batteries have memory but just not as pronounced as niCd. So erasing the memory effect does wonders.

6566844
6504344
6469473
6441584
5998968
5698961
5493196
20080079397

 

My engineering background certainly wasn't focused on chemistry which is the most relevant here.

 

Wow. I looked at this and it involves putting holes in the modules right? Whew.

So far, I'm more interested in technologies that recondition dead modules using a capacitor to pulse a charge which dissolves crystals, and then reconditioning via deep discharge using higher current at lower voltages for near constant power to correct memory. Plus there is discharge and charge pulsing that can correct the internal impedance problems. And all that without drilling any holes.

But I will read about hydrating. Perhaps that is also necessary in some scenarios.

 

Bisco, my thinking: one of the biggest ways to improve technology is cross industry learning. So I'm interested in how fork lift and other batteries for military equipment get reconditioned. There are some inventions and patents and a few companies pioneering the reconditioning for those. And that reconditioning industry seems more mature and better funded than for EV and HEV since the military pays dramatically more money for new batteries so the potential savings of reconditioning is greater.

Just some musings as I research.

 

Do you know what I really want right now?

Dead Prius modules. I want to experiment on modules that others already threw out as trash.

I would test their voltage, capacity, impedance, self discharge and then try the different methods
for rejuvenating that are in those patents and see how well they improve.

Also, I want to find out how to graph the voltage curve during discharge like is shown in several
of those patents as a measure of the batteries performance compared with new batteries.

 

Brand new batteries seem to cost much more than that from dealers. In fact, I see reconditioned batteries with 4 year warranties at over $2000

So it seems viable but who wants to buy a reconditioned battery that fails often even if the warranty will cover it for a year? I don't. So I'm researching how to confirm the reliability of batteries after reconditioning. It's difficult to find hard data and research into this.

However, scientifically, the chemistry is such that it seems clear that it's possible to "reset" the ions inside the battery, dissolve crystals, and reduce impedance by different reconditioning techniques. If that is true, then it will greatly extend the life of a battery nearly to the original life when it was new.

 

Also it seems clear that you can measure the chemistry inside the battery for it's health by measure those same factors like self discharge, internal impedance, capacity, and voltage to determine that the internal chemistry is comparable or close to that of a new battery. It's crucially important to be able to measure this.

I don't want to "rejuvenate" a module and it works for only a few weeks and fails again. I don't want this as the business nor for the customer to have this frustration.

 

(And not for my daughter either! )

 

Hmmm I just bought 12 "dead" Gen II Prius modules on eBay for $68. This will give me something test rejuvenating. If only 10 of them can be rejuvenated that will be $400 worth of modules for $68. Otherwise it will be a $68 learning experience. ha ha

 

In the Cadex Battery Univerity, they talk about how in the military they user Nickel based batteries for aircraft and they have very strict battery maintenance schedules which includes reconditioning by discharging to 0V for 24 hours and reusing them over an over. They explain how it's done and I expect that will work with HV niMh car batteries also.

If military aircraft engineers recondition and reuse niMh and niCd batteries where you they extreme need for reliability more than automobiles, then that should be good for automobiles also.