Current State of the Art in Battery Balancers?

This is an individual module test on a core 2nd gen battery purchased on Marketplace that's been refurbished before and failed and has been sitting 6 to 12 months. Some good modules from this battery will be used to fix the two 2nd and 3rd gen batteries that are being refurbished.

This is the Harbor Freight Viking Battery System Analyzer. It's a 12 volt tester so the readings with a 7.5 volt module are not too accurate, the CCA for sure. So while the readings may be inaccurate they are consistent, so it makes a good comparison test so the bad modules can be identified. Its noted on some of the YouTube battery refurb vids that you can't just grid charge a battery that's got the red triangle P0A80, you have to locate and replace bad modules before you grid charge or the battery will fail.

It looks like the modules are either in the 7.5V range or the 6.3V range with not too much in between. And the CCA numbers are all lower, and the resistance readings higher, with the 6.3V readings. Also it looks like an abnormally high internal resistance reading of 8.87 m/ohms is an indication of a hard fail with the 6.07V, 338 CCA readings being one of the lowest in the pack. There's also one module the tester refused to test, a volt meter reading was taken on that one at 5.68V. Also note than none of the low voltage modules are together in any of the 14 battery blocks. So all the bad blocks are only 1/2 bad. Also note the worst modules are in the center of the battery where it runs hotter. It's recommended that you swap the center modules to the outside before you grid charge.

All 3 of the Prius battery apps were used on the CT200H but I haven't yet been able to really pin down which modules are bad or good the way this Viking tester is doing. But I'm still learning the apps. Also note the apps only test battery blocks not individual modules because that's the way the ECU's look at the battery. So you are going to have to additionally find the good and bad modules within a bad block.

Right now it really looks like this is an economically viable endeavor, if you have the time to spare. About $1200 total investment so far which includes charger / discharger, core battery, testers, OBD2 module, app upgrades, new buss bar hardware. I spent $1500 5 years ago for the new D cell conversion and that's about the price of a refurbished battery. And the $1200 will get 2 batteries up and running, and the charger will be used again to maintain the batteries and extend life.

 

I'm a HW/SW/FW engineer myself. I understand circuits, but never have designed them professionally, working far more on the SW/FW side. That said, I've been collecting tidbits to do a variation of what you're describing... Just hasn't come to the top of my stack to Get It Done quite yet. Can't wait... looks like a fun project!

* Primary difference: what I'm aiming for is accurate, repeatable characterization of battery modules (each w/ 6 cells, so nominally a bit under 10VDC total). Doing that is NOT easy right now. Once I have that data, including reasonably accurate internal resistance, I firmly believe the important elements of a battery pack rebuild can be done with solid confidence:
* Eliminating bad modules
* Creating module pairs that pass muster in the Prius
* Sorting the pairs so the most at-risk pairs are on the outer edges (coolest temp)

A few items look pretty useful to me:

* TestController: a free app able to drive a WIDE variety of power supplies, loads, meters and more.
Program that can log from many multimeters. - Page 1
Test Controller introduction
* Programmable power supply, such as RIden RD6006
* Progrmmable load, such as DL24MP (150W per module, can have up to 9 modules!!) with 4 wire sensing
* A programmable meter able to do the measurements needed for reasonably accurate internal resistance measurements, ie low resistance at significant voltage or current. I happen to own a Fluke 8808A which while a bit slow seems reasonable for the task...

Put those together and it's not too hard to cobble together a rather nice module tester!

Now I can't wait to get back to this

 

MORE INFO

So I did a road trip to Sacramento to get a core Camry hybrid battery, to have spare modules to replace bad ones. And it was a Hybrid garage run by a guy that's been reconditioning hybrid batteries for several years. He shared some info about the process.

He says it's key to load test the individual modules to find the bad ones and replace them before reconditioning. He uses the Neiko 40510A battery load tester which is on Amazon for less than $40. It load tests to 100 Amps which is similar to what's happening when the car is using battery power. It confirms with a different reading what the Viking tester is indicating when a module is bad. It's a 6V and 12V tester so it can pretty accurately test the 7V modules.

So here is the individual module test on the just acquired Camry battery. This is a newer battery (never reconditioned) than the first core battery tested and the Viking test readings reflect that, all volt readings over 7V. However there's one module with a very high resistance reading of 27.69 mille-ohms, but it also reads a good 7.61V but a bad 108 CCA. So you can't necessarily go by voltage. This module is also the only one that fails the Neiko 100amp load test. There's also a couple of modules that have better readings than all the rest, below 5 m-ohms resistance, and above 600 CCA.

So it's looking like you should not mix older modules with newer ones. Because it may be imbalanced. It might be a good idea to know the mileage if possible of the replacement modules you are using.

Also ran the Neiko tester on the first core battery, it indicates all the modules that are around 6V are bad.

This guy also gave the skinny on the dash instrument cluster blackout problem. He said the upper right capacitor is the only one you need to replace.

 

You're still getting a USED battery. And mixing older mixed life blocks.
And it only takes one weaker block to get the code and strand you.... Hope you have tripple a....

 

Why don't you let up on that? I think he knows it's not a new battery. Just because he isn't doing what YOU would do doesn't mean it's wrong. There is a whole industry built on used hybrid batteries...people know it's not the same as new. Maybe they don't have the money you do. Maybe they need a less costly solution even though it may end up being a shorter lifespan.
And maybe he is just wanting to learn more about this whole process.....

Seems as long as people on here are doing what you agree with then you are nice to them, ...but if they do something else you view them as some kind of idiot and let them know it.

 

It is more correct to restore the capacity in the modules at the beginning and only then test them. It's impossible to inspect a part without cleaning it first. I restored 2 batteries so far with replace hybrid battery code P0A80 without replacing any modules.

 

Good info. How many miles did the 2 batteries have on them? And how much miles / time did you get out of them?

 

One battery was on a 2008 Prius with 260k miles. The battery was not original. It has been almost 2 years since it was reconditioned. Delta SOC was a couple of percent, either 1% or 3%. One module was weaker than the others.
The second battery was on a 2010 Prius with 163k miles, original battery. 7 months have passed since the reconditioning. 2 modules differed in voltage from the others. Delta SOC was ~30%.
Both batteries were discharged to a couple of volts. The 2010 battery was discharged once to 1.8 volts.

 

Did you mean the whole pack was discharged to such low a voltage? What discharger did you use? How hard is it to manage the discharging without reversing the cells?

The reason is I am planning to DIY recondition my 2012 Prius (144k miles) that just threw out a P0A80 code.

 

So the Delta SOC (State Of Charge?) is the difference between the best and worst blocks?

And you're saying it doesn't matter the condition (to a certain extent) of the modules before recondition you only need to test after conditioning. Because even if they are initially weak / bad the recon can make them good?

The reason I'm testing before is to learn and see why the assembly is bad and throwing P0A80, and just learn the whole process. It comes from years of being a tech, you usually diag before tear down

So your discharge number of 1.8V, that's module volts?

What charger discharger are you using and are you only testing with the smart phone apps?

 

You're still using old used batteries, that are likely about to die.
You're sure doing a lot of work with old blocks, that likely won't last long.
And how much money are you spending for this used iffy stuff?

Are you just doing it because you just want to play around with it and it's not about money?
Or are you trying to get it to survive to keep the car alive on a little money as possible?

 

It's a mix of reasons. Used to wrench at a Toyota dealer and was always curious about the hybrid batteries, and they wouldn't let us work on them except for replacing them with new. Some people when you tell them they can't do something it makes them want to do it more.

Bought a Prius in 2011, an '05 with 12K miles. In 2020 with 80K on it the Hybrid battery died. So the factory battery lasted 15 years and 80K miles. Replaced it with a new $1500 D cell conversion (orange cells), don't remember the name of the company. A couple months ago got the P0A80 red triangle again, so it lasted 5 years and 60K miles. Been wanting a CT200H anyway, and the Prius has sort of been a lemon. Found a 2011 CT with 125K mi for $7K. Wouldn't you know after driving it for a week got the red triangle. So two Toyotas both with the same dead battery.

When the 1st battery died DIY reconditioning was in it's infancy. It's gotten a lot better lately. Before it was only charging individual modules, very tedious. Now it's grid charging that also discharges and equalizes without disassembly. Quicker, easier, and probably better results.

Spent so far
1) Prius core battery $250
1) Camry core bat. $250
1) Charger / discharger / balancer $750
2) Battery testers $80
2) Bluetooth OBD2 Modules $100
2) Smartphone app upgrades $35
1) Misc. $35
TOTAL $1500
And that will fix 2 batteries, and more down the road if there's another Hybrid car or some side work. There's 3 neighbors with Prius.

2) Sodium Ion batteries $3800

2) New factory batteries $6000 - $7000?

Yeah the recon is not going to last as long, but thinking it could get at least 1/2 the life of new, especially if you know the date and mileage of the modules. The Lexus battery is original and all the cells test good. So it made it 125K and 14 years in a very hot climate, and I've seen original batteries go 250K. Seems like it could make it to 200K especially with some maintenance charges. That's 5 years of driving. That seems worth it.

That brings up a question? How much mileage / time are people getting from their reconditioned factory batteries?

Sure the Sodium Ion battery is sweet, 2/3 the price of a factory part, lighter weight and more performance, and a company that backs their stuff. But just spent $7K and have spare time to try this out. Thinking there's also an environmental factor, like recycling and reconditioning (regenerating ;>) , That's kind of the idea of a Prius in the first place.

 

Yes, the whole pack. I discharge so low when there is a code P0A80 or bad module(s) in the pack.
I doubt that the reversing can occur during discharge. It takes more time for this to happen.




I also have a self built charger that also works with prius c (20 modules pack).
The voltage display is lying on this charger, so I installed my own, which has a Bluetooth option that allows you to see the voltage on your phone when you're nearby.
I was going to install a wifi module, but I couldn't set it up with my router. It takes time to figure it out.

 

What is a Delta SOC can be found on this website. This is the state of charge and discharge of the blocks. The computer monitors all 14 blocks, and if 2 or 3 blocks (I'm not sure how many) differ from the others, the computer triggers the code P0A80 replace hybrid battery. Usually, when the P0A80 code appears, there are 3 bad modules in the battery pack, in three blocks. One bad module can usually be seen by the voltage, but the other 2 need to be found.

Before cycling the whole pack, I mark modules that differ in voltage from others by 0.3 volts or more with an exclamation mark, and then I look at what has changed.

 

Do you use a Mean Well LED driver for Prius C? If so, which model?

 

Okay, that makes sense. Tested the CT200H battery yesterday and 2 modules are .03V below average and one is .03V above average.

So that would mean this battery is recoverable compared to some other modules I tested, several with only 6 volts and one with 27.69 m-ohms internal resistance.

EDIT: Nevermind, you said 0.3V difference. I'm only seeing 0.03V difference
.

 

All you need for the prius C is to use 3 power supplies instead of 4. The Prius charger for 28 modules uses 4 power supplies and 1 LED driver. The prius C requires 3 power supplies and 1 LED driver. Do not exclude the LED driver, as it stabilizes the current at ~350mA. I adjusted the power supplies in my charger to 245 volts instead of 250 volts.

 

Okay, you're just kinda playing with them, to get as much life out of them as you can.
And it gives you something to do.

 

Okay, the 1st attempt using the original (125K mile) battery in the 2011 CT200H is a fail. This was with the Prolong charger discharger running 3 charge/discharge cycles, and taking about 4 days. It's hard coding P0A80 and the Prius app says 23% life, which is the same as the original test.
Further reading and watching YouTube vids it looks like amp hour capacity of the modules is the true test of the battery. And it's how a lot of techs determine if a module is re-usable or not. And most DIY techs are using hobby chargers and chg/dischging individual modules to get an amp/hour reading. With up to 5 chg/dischg cycles to get the modules to a usable amp/hour capacity level.
I'm probably not doing everything right yet either, like there's one tech that balances the blocks with each other using a low/high module in each block, essentially averaging/equalizing the amp/hour capacity of all the blocks.
Also could have done more cycles with the Prolong, only did 3 and techs that charge modules individually go up to 5 cycles.
Another thing is balancing. The Prolong balances using overcharging and their tech says it's a different kind of balance than how a lot of YouTube vids show stacking the modules all facing the same direction and wiring them in parallel and leaving it sit overnight, going to try both ways.
Going to retry with this battery using the individual module chg/discharge amp/hour capacity test to find bad modules. Using the Tenergy T-180 100W Intelligent Balance Charger. $75 on Amazon. Prolong has a module tester but it's professional level at $900.
It's more time consuming doing individual modules, up to 6 hrs per, so will be looking at the other readings previously taken to see if one of the quicker tests correlates to a bad capacity reading.
Also there's a lot of different opinions on how low to go on the discharge volts, between 6V per module on most YouTube vids, 3V with the Prolong, and others going even lower.
There's also different opinions on what's a good amp/hr reading. With 6.5 amp/hour being new and 5.5 being a good minimum but as low as 5.0 being usable.

 

You need to find the reason why it didn't work, rather than panic. You already have the Prolong charger. That's all you need to restore the battery capacity along with replacing bad modules. The discharger that discharges only up to 84 volts... to me it's useless, but even after discharging to 84 volts, the result will not be bad. The battery with 125k miles shouldn't be that dead. I tried to restore a battery from a 2013 prius with 186k miles. The owner was told first of all that the battery needed to be replaced, as the battery filter was clogged badly and the Dr. prius test showed 13% of life. After three cycles the dr. prius test showed over 60% of life, with still 5 weak modules in the pack that needed to be replaced.
Have you cleared the P0A80 code from the hybrid computer? Gen 3 does not erase the P0A80 code until it is erased with a scanner. If the code was erased and reappeared, what was the percentage of delta soc?
What voltage was the battery charged to at each cycle?
Has the battery cooling been used? If you do not use cooling, the battery will heat up and the charge will go into heat, and the voltage will not even reach 235 volts. On a low miles battery, the voltage reaches 237-239 volts. On a worn battery, it can reach 243 volts.
You don't need to cycle it 5 times. 3 times is enough while 1 cycle is not enough.
If this is an original battery with all original modules, then the difference between the modules should be not higher than 0.03 volts after cycling it 3 times. Discharge the entire battery to 40%, wait 10 minutes until the voltage settles and measure the voltage on each module. The lowest voltage on a bad module will be visible.