Interesting bit from greenbean battery.

96% is the number most commonly referenced for reconditioning... That's pretty close to 100% if you're writing promotional literature to sell GreenBean...

 

Hobby chargers are not able to accurately make those measurement... You need more expensive equipment than that!

 

I don't think "expensive equipment is required" at all.

If I take 28 modules from a brand new, off the shelf OEM HV battery and cycle test them with a specific procedure, I have perfect information to use as a "standard". I've done this. I've posted this procedure a few times on the forum. Any hobby charger can use the same exact steps.

Any "previously used" modules tested afterwards, using the same exact procedure, can easily be compared to the values obtained from the "new OEM" modules. The absolute accuracy of the numbers doesn't matter. What matters is how does the "used" module compare to the "new" modules. If 28 new modules average 7600 mAH using a specific methodology, then if I test a used module using hte same exact methodology, I have a pretty clear indication of how it compares capacity wise.

So, I wonder just what is the capacity number they use for this, or if they just base it on the 6500 rating.
Modules are extensively reconditioned through proprietary technology to achieve the same capacity as new OEM cells or modules.

 

Hi TMR-JWAP,
Do you by any chance recall the date or title of the posting(s) where you posted your "standards determination" procedure please? This would be really helpful information for me to use testing modules. Thanx in advance. Aloha.John

 

While I agree that with enough patience and determination you could get accurate readings from cheap gear in theory; in practice I have a hard time with that because I have seven SKYRC chargers and 3 of them are newer with higher wattage and faster processor than the other 4 which have way slower processors and 2 of these 4 weaker chargers shut off early with an overcharge error that's not really an error. And when they shut off that way you lose all the data for how much charge was sent. Same when you accidentally bump one of the alligator clips and charger gets disconnected. What's more I like to charge in stages to keep heat build up to a minimum. So all these hassles make it difficult to get accurate charge data.

However, if you had chargers that stored data better, and ported that data to your laptop, as well as bought a bank of these dischargers: https://www.ebay.com/itm/184266440118 which also port data to a laptop and then did as TMR-JWAP suggest regarding getting base line data with a brand new OEM pack for the exact system that you're running, I think you could eventually crunch all that data into some interesting calculations and eventually refine your ability to do it near as good as someone with tens of thousands in lab grade test gear.

But would your data be good enough for a 3 year warranty, which is the high water mark in terms of battery rebuild longevity?

 

I agree - if you're going to do this as a real business, which includes dealing with warranty claims, valid or not, and maybe lawsuits at some point, because the customer always thinks he is right, then having good gear and a good paper/data trail is probably a smart move. And if you need to do a lot of modules for the business to be profitable you can't spend 3 weeks on each one. If you're just doing it to keep a Prius or two with HV bat codes from becoming unusable before it rusts to dust, then being able to quickly discard modules which are reasonably likely bad, even if you make a mistake or 10, saves that precious resource of time.

And, as an aside, warranties are an interesting thing. Most/many of those offering warranties will expend considerable effort to not honor them if at all possible, often simply due to cost/benefit. And this can take many forms. Having to ship back to China, or pay high return freight costs are just 2 examples. But they have to weigh that against getting a bad rep.

 

yea... agreed on all points. I gave a one year warranty on my original battery pack that I sold for $700 because it didn't have a bad module yet and I just reconditioned it, so it was worth the risk. But I've yet to warranty a pack after it's had a bad module. Instead I just keep the rebuild charge in the $300 range and can replace additional modules after first rebuild in the $200 range or lower. That way they get a pack that's cheaper than a rebuild business, but with potential risk to pay more later. I have a couple friends in town that do it this way too and once it's time to change out bad modules for the third time the customer is usually ready to get it fixed for good or go without their Prius until they can afford to have it fixed for good.

 

Interesting. Thanks for the follow up. I appreciate you sharing and allowing me, and others, to learn from your experience. As a rough estimate how long would you say - for you and your friends - that your reconditioned batteries are "trouble free" before they need another changed module? Asking because when I do it myself I'd like to have an expectation from (your) experience as to how long before I've gotta do it all again. Thanks in advance. BTW, different topic but just FYI, I got a bootleg Techstream from eBay, installed it on my primary (!!) Windows 10 laptop and have had zero problems or concerns. I know some people have great fear of hackers downloading their hard drive via some hidden code in Techstream, and some say you can only use old Windows, but the above is my experience.

 

There's a bunch of variables involved in reworking a group of used modules into a functional pack. Lots of smart people on this forum with lots of experience.

Me, I read the "individual module replacement" mega thread. Came up with a conservative plan and got some hobby chargers (and a discharger). Spent a bunch of time doing it and now 2 years - 30k later the HV battery still seems to work fine. 150-300mV difference. MPG of low 40's in winter, almost 50 in summer. Some point I'll see what DrPrius guesses the capacity at.

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