Gen II Prius Individual Battery Module Replacement

I am charging my last cell this morning and was going to do the parallel thing after discharging all cells to match the lowest 7.4v ...but based on the Gurus advice ..discharge to 7.4v and reinstall -- I don't really have a way to parallel charge .. unless I do like the guy on youtube with his (2) 12v jumper batts hook in series and then put (9) sets of 3 cells in series tied together in parallel . which looked even more mickey mouse than my Toy charger set up .

Anyway here is my report so far with the Toy Charger at the more gentle settings (Discharge 2A to 6.3v, 7500mAh capacity 3.0A charge X 3 cycles) .

From what I see .. purchased Car with junkyard batt installed ..most of the less energetic cells start with 254FEA so figure came out of a 2005 and lots of cell replacements --I have done a 6 pack over last 1.5 years and this time 7 cells replaced at once instead of 1 or 2 . Also last 6 bought on eBay were really good cells ...wish I would have bought all of them .. may need to buy some spares from Ericbecky .

Mainly am going through the motions on this so that the next time a cell falls out of working spec will see where it fell on my chart and replace 'like cells' at that time too and try to put together a year of trouble free driving ..

Kenny

 

Kenrico, I thought the latest poor man's balance concept was, as above, to discharge all modules to 6.6V, then charge each one with only 1000mAh, and re-assemble?

 

LOL... anything reasonable works. Generally, my recommendations are particular to the equipment used, and it's usually a variation on the same theme with an attempt to address any specific concerns or problems I might see. The theme being, match based on voltage response to a current... because that's what the car does... it pulls or pushes a current, and the blocks have a voltage response.

The one concept that is just ill-conceived is the parallel harnessing. It's extremely ineffective. If you've already discharged or charge to a set point, the harnessing is particularly useless. Equalizing resting voltage has zero value. Knowing that the modules will have the same response to a given current is WAY more important.

 

Well last module topped out at 7501mAh cycled twice (a good one) so am done now .

With my Reactor 250 I can discharge to a certain voltage like 6.7 or 7.4v (the lowest modules voltage currently) or charge upto a specific mAh like 3451 mAh ( my lowest seems too low) .. let me know a good strategy to across the board before puting the pack back in the car.

I appreciate..there is alot ot digest in the 74 pages of this thread and some opposing views so having a clear suggestion based on my pack is helpful . I will try to save my spreadsheet in landscape and repost in a few .

thanks Kenny !

 

For the lower discharge rate of the 250W, I'd do whatever is most convenient.

If all your modules have been discharged, just input 2000mAh @ 20A. If they're all fully charged, discharge them to 7.4V.

EDIT... on second thought... @3A may take a while to get to 7.4V on all your modules. Pick your lowest capacity module and discharge it for 5 minutes and see where that puts you. Use that as your target for all your other modules.

 

Well, used the Reaktor to discharge cells to 7.4v .. most twice - when they hit 7.4 they 'sprung' back up to 7.5+ ..those must be the good cells.

Then I installed the buss bars back on, hand threading each nut, tightening with socket by hand, and then using socket and wrench for last quarter turn 'snug'. Which worked great, but last cell on the snug the nut and terminal ear came sheared off on the first cell . This is the first time in 2 years I do not have a spare cell as the extra one I ordered and the one bought local were utilized when the quanitty of cells under 7v went from 5 to 6 to 7 .

So came back in and ordered 2 more cells off eBay ..

The thing that really bugged me yesterday is that I was reviewing the thread about best price new battery purchase. Most dealers were not honoring the posted internet price or if ordered online were told they don't ship ect..and the best counter prices were $2500ish. But the tidbit that really got me was that the core wasn't refunded at the parts counter..it is refunded after Toyota receives the core pack and confirms torque of the nuts and all cells sealed . So the new batt is $2000+ plus tax $200+ and core $1300+ you are right back at those 'dealer' quoted figures out the door and you will get the core money back eventually.. my junk yard pack would have to be rebuilt (again) just to buy the new one as it does have a few broken screws on the underside cell retention.

So it RE RE emphases the value of a local, low mileage pack or even a reasonably priced core ...

Kenny

 

Sorry to see that happen! I'll probably aim for only 20 in lb torque on these bolts after seeing your threads pop off!

How are you finding cells on ebay? I tried one buyer who had sold thousands and I got very low capacity cells, then I tried a seller who hadn't sold any previous modules, and got good ones..

 

Did the same..not the big movers with lots of ads..guys with 1 ad ..this last batch proved to be decent and he had a lot of 24 to sell initially..which sounded right

Kenny

 

48 in-lb No more, no less.

Nobody told you to discharge them twice. There is absolutely no reason to do that. When you remove the load from a battery, it's voltage increases. It's supposed to happen. It's how they work. A module at a resting voltage of 7.4V is close to empty.

Steve

 

Here's why.

Battery Fire | PriusChat

 

Finally, I'm back on the road again after two weeks of battery maintenance!
Like others, I did my first test drive without reinstalling the seats, side panels, and floor coverings. I've never really noticed the sound of the relay switch when the battery clicks on before now: its pretty loud when not muffled by the carpet & panels! I always thought the car had a lot of road noise, but now after hearing random rocks click into the undercarriage and hearing the gas slosh around, i'm much more appreciative of the sound dampening it does have.

 

Hey guys,
Just finished my first reading through the 74 pages in this thread. It was quite the ride. Thanks to all of you for contributing to this thread, it was quite the informative read. I recently took out the battery in my 07 Prius and from my initial testing it looks like one module needs to be replaced. I have the time to do it with the hobby chargers. I am looking to purchase some version of the Reaktor, but I have a couple questions.

1. Is one 1000W Reaktor enough to do the job in a reasonable (a week or two) amount of time? Is it better to purchase many smaller chargers?

2. I'm still a bit confused as to how to get the full discharge rate from these. If I read it correctly it cannot be connected to a modified power supply.

Thanks in advance, sorry if these were already thoroughly explained.

Al

 

Kudos to you for making it.

The 1000W is enough and is kinda easy mode. You can finish the discharge at about 13A consistently. It will do this on its own with a suitable 12V power supply.

If you power it with a battery, it can operate in regenerative mode, i.e., when it discharges your module, it charges its power source. When you can go this route, you get 20A on the 300W or 30A on the 1000W. I'm a fan of 20A. There are also dual and quad versions of the Reaktor 300W. Again, if you can reliably discharge into a battery, that's your best bet. It needs to be a big enough battery to handle the 20 or so A you get with 2X 20A discharges into it without beating up the 12V. The $90 122Ah deep cycle marine battery from Wal Mart works, BUT keeping the 12V in a working range can be a challenge. You'll need to be able to charge the 12V at 2-6A depending on its state of charge.

Again, easy mode is the 1000W. You get the benefit of 80W of internal discharge power. The 300W are limited to 20W each and should really be used in regenerative mode. One full cycle on the 1000W will take 2.8 hours with 30 minutes rest between each leg. 6-7 cycles per day. Rounding down, 2 modules cycled 3 times per day = 14 days to cycle the whole pack.

Dual 300W + regenerative = 2.6 hr (charge takes 1.3hr, rest takes 1hr). With proper timing, you could do 6 modules per day.

The downside to the cheap quad chargers is their 5-10W discharge power and typically 50-80W charge power limited to 5-6A, Which can make deltaV charge termination less reliable. Additionally, their low discharge power (at 1-2A) can give you very misleading results when compared to the 80-120A the car can use.

Steve

 

Thanks for the answers Steve!

I like easy mode, what I'm having the hardest time with is trying to figure out the cost to time ratio which I can devote to the car. From what I understand, it would be even easier to use a grid charger after replacing the module. This would get me on the road faster, but I will not know the individual capacities of the modules so I could potentially have modules that will fail soon.14 days is not too bad, but I doubt that I will be able to keep the chargers going consistently enough so I have a feeling it would be longer.

So I can reduce the time by using the dual or quad chargers, but the results will not be as reliable as the 1000W charger. Which option would you recommend between using the quad chargers to balance the battery, or using the Grid charger?

Al

 

The grid charger is easiest mode. If you don't have any failed modules, and you have relatively tight deltaV except near the bottom of the SoC range (assuming you have techstream or torque pro to check), to hell with module work. Grid charge/discharge/charge. WAY less touch time and WAY less calendar time.

Since you say you have to replace a module, where are you getting it?

 

Also way less chance for error!

 

I ordered one off Ebay and was going to test it to see if it was any good. Is there a go to place to get reliable modules that you guys prefer? I may of missed that in the thread.

So the dream would be something along the lines of getting a good module with at capacity that is at least better than my worst original module. Then I grid charge, and hope that my original modules benefit quite a bit from the re balancing, and one of them is not due to fail shortly. Hmm I'm not completely opposed to this as I am an optimistic individual, but it would be a bummer to have to deal with the whack a mole every 2 weeks or so.

Would the whack a mole grid charger approach eventually yield the same result in that the poor modules are eventually replaced?

 

I didn't miss a "go to" place. I would ask anyone that has recently purchased modules from sellers to post their auction link and results.

If you can find a seller that will guarantee some kind of performance, that's the one to buy. The vast majority only provide some sort of voltage guarantee, which is covers the first of several criteria. I have a module that will hold voltage and charge for months... but it only has 2700mAh capacity due to one of the cells being lower capacity than the others (likely electrolyte loss).

Yep. Got it on eBay.

 

An update on my 06...

First cell failure was May of 2015, bought 2 Gen3 cells on Ebay, replaced the failed one and its paired cell. Drove it until it failed again this Jan. One cell again, so I grabbed the good one removed last year and tossed it in place of the dead one, and drove it again. $80 invested in "repairs" so far.

Got another P0A80 again a few weeks ago after a few thousand miles and parked it, hadn't gotten around to testing to see which one it was.

Stopped by the recycler 4 miles from home to get the hatch struts from an 08 they had for my MILs car, and the dash panel above the steering wheel so I can inset my SG2 in it (I prefer getting a spare panel when building custom stuff so that if I screw it up, I can easily reverse it). No HVBatt in it.

Asked about it in the office, and the guy said
"You know EVERY time I sell one of those to a dealer, they're fine, and EVERY time I sell them to a person, they're bad."
"So you sold it?"
"Yeah, the person said it was bad, it's over there."
EEP!
"How much for it as is?"
"I'll sell it for the $400 core charge."
"Do you mind if I test all the cells in it?"
"Sure, have at it"

I pop the cover off, they only have 4 bolts holding it on. He says "I'm always ready to learn something", and watches while I pull it apart and get to testing. The terminals/bolts on some cells are lightly corroded, but not green or black gunk, and the copper buss bars are still copper colored! Not heavily blackened like mine were. It doesn't look like whoever bought it swapped the cells on it before bringing it back. I don't have my DVM with me, the one they have is analog and useless, it maxes out when set to 10V. Not good.

"I'll be right back, I'm going to go grab my digital DVM."

Book home, hook up the laptop to my car, find out that it's a single cell that is bad again, and it's the original one I threw back in a few months ago. What to do, what to do...

I figure I'll ask if they'll take $350 for it, if he goes for it, I'll grab it.

I head back over, start testing all the cells, all are at 7.50v +/- a 0.02, except cell 1 at 7.44. I WANT THIS PACK. As I am testing it, he starts talking about how if he sells it to the rebuilders that sweep through from time to time, he'll get $400, but if he stacks it in the general battery rebuild boxes, he'll get $250 for it.

"Now the reason I'm telling you this is that if you want it for $300, you can have it."

Needless to say, I bought it.

Head home, and wonder - if I just toss it in as is, transferring a couple of missing sheet metal panels, will it be worth the time? Decide to go for it. Rip out my pack, toss the "new" one in, bolt it down and hook up the cooling ducts. Cross my fingers, and turn the car on. No DTCs. No new errors from the TIS program on the laptop. Voltages within 0.02 except cell 1. Resistance of ALL cells right at the 0.022-0.024 they're supposed to be, it fluctuates, but ALL cells read the same as it does.

Blast up and down the street. Run back and get my wallet, drive it back to the boneyard as a test drive.

Point to my car - "there it is".

"That's on the new pack?"
"Yep, works fine."

"I'm glad to know that you got it working rather than a rebuilder grabbing it and throwing a "rebuild" sticker on it and selling it for $2000".

I have a new favorite auto recycler! He now has my name/number so he can call me if he gets a Toyota hybrid in, I'm willing to hook up my M-VCI and run tests for him before they start parting them out.

Now to heavily abuse the car for a few weeks to see what happens...

 

Very nice find.

Run the discharge test in my sig and log with Techstream. Takes less than 20 minutes. You'll know exactly where that battery stands.

Steve