Hybrid Battery Dying/how do I determine which modules to replace using DRPrius?

pack voltage seems high to me, so keep that in mind after you replace and recondition.

 

There are 14 battery blocks as shown in the app. Each block is made up of two modules, so there are 28 modules total.

Based on your screenshots, blocks #4 & 5 are suspects, but I can not be sure. Usually, one cell in a module goes bad, and you see a 1.2v difference between that block and the other blocks. I do not see that in your case.

Posted via the PriusChat mobile app.

 

That's only set #1

You don't need one, but you would see more info about your pack if you have one.
But remember, your not going to understand some / all of the data you get the first few times you cycle modules unless you read what others here have posted about their packs.

Unless you know what your doing you could make the pack more out of balance, that way. No one can tell you yet what you might find doing that.

No, that is what grid charging and reconditioning the pack is all about.

 

A few thoughts:
1) The best app I've found for finding bad blocks (module pairs) is Hybrid Assistant's battery test, and associated reporting:
- Get your battery to a below-50% state
- Fire up HA monitoring
- Drive in a way that forces big charge and big discharge (serious braking for a couple of seconds; floor it going up hill )
- Examine the battery block reports. They show exactly which blocks are WAY out of whack compared to the others. (I wish the colors/line thicknesses were more distinct, but oh well )

2) This part you can do without fully dismantling everything:
- Goal: (a) discover low-volt module(s); (b) See which ones are bad enough to replace. THIS WILL NOT TELL HOW TO FIX IT!
- Needed no matter what: a reliable digital voltmeter (DVM); 8mm and 10mm sockets; small torque wrench for re-tightening 8mm nuts. Getting the torque wrong can be quite costly. I have a junky 1/8" Harbor Freight one. It works.
- Needed if you likely have one or more bad modules and want to prove it: a 12-18v 75W+ power source, and a hobby charger/discharger. I have a SkyRC iMax B6 Mini. It's cheap, reliable (except internal resistance), but slow (minimal bad-module test takes a few hours. A good module can require overnight. With better unit you can do multiple modules at the same time, and charge/discharge faster.

I'm right in the middle of finding two (maybe more) newly bad modules on my Gen3, so this is very fresh:
* Got the car to around 50%
* Let it sit overnight (self discharge is one failure mode!)
* Without removing the whole pack: expose it (requires one 10mm bolt removal); learn how to remove the orange safety clip and do so; remove the black air vent (one plastic clip) and the metal cover (a bunch of 10mm nuts - don't lose any!)
* Now, remove the 8mm nuts on the back side. GENTLY.
* Every module is now isolated!

Test #1: Record the voltage of every module
* My example: two modules are 7.51 and 7.52 volts; two are 7.54V; One 7.55; two 7.56; the rest over 7.60V
* I seriously suspected the 7.51/7.52 are BAAAD. Cautious about 7.54; The rest? We'll see.
* (One easy next step: wait a few hours and remeasure. As long as you were not close to 100% charge, NO battery should drain much in a matter of hours. Self drain is pretty obvious.)

Test #2: Find some measure of charge capacity.
* With my SkyRC, my settings are: (6 cell NiMh), 2A charge, 1A discharge (never gets more than ~0.6A discharge), 4 mV dPeak, end (dischg) voltage 1.0V (ie 6.0V module), (system: Max temp 40C (basically disabled), max charge 9000 (also disabled), no max time.)
* For this 'quick' test, I have it do a single charge-discharge cycle. From experience and others' wisdom, I want to see at least 4000 mAh capacity. IMPORTANT: all numbers must be used humbly, ie just relative to my own situation...
* The 7.51/7.52 modules are 1579 and 2379 mAh. Yep, awful.
* The 7.54 modules? 3139 and 4102.
* The 7.55 is 6078. Not a problem.
* I wouldn't bother testing the 7.56's at this point, but I'm doing other work so may do so just in curiosity.

I have spares: 2 over 6000, 2 over 5000, 2 a little over 4000 (emergency use?)
I'm thinking I will replace everything under 4500, and also order two spares for next time...

What's next?

A) Get everything fully charged. I have a Prolong charger so I will reassemble, and charge. And use the SkyRC to charge the replacements.

B) Pull the whole pack and do a "proper" comparative test for all 28 modules:
- two 55W headlights in parallel
- measure before volts, run 2 minutes, measure voltage several times:
- immediately after start (initial drop)
- 30, 60, 90, 120, 180 and immediately after disconnect
- to do this with the replacements, they too need to be compressed for the test. ABSOLUTE MUST.
- if ANY modules drop 1.2V or more, they are DEAD. A bad cell. Must be replaced
- then I calculate the delta voltage from after-start to before-finish (and the others as well but usually not needed)
- usually if I sort from low to high, then pair up modules highest+lowest, 2nd, 3rd etc... that gives me blocks that match as well as I can get them.
- My primary goal is matched voltages under load. I don't yet have a reliable way to measure module iR.

END. Hope that was a little useful!

 

You are using some form of cooling ? I'd HOPE, at any charge rate, specially at 5 AMPS, while observing compressed module swelling.

hope others can respond bout setting issues.

 

Today, I see what looks like a fan in the last pic. Needless, you should be monitoring module temp while charging too. If the module fells hot to the touch you should lower charge rate or stop charging and let it cool before it swells.

 

I played around with hobby chargers and my old pack - the cells always expanded due to heat. I clamped them in a sandwich type clamps, but any swelling - even tiny will make it so you can't get it back together... Id suggest a lot of reading ..

I ended up finding a 80k HV pack at a wrecking yard for 600... Maybe charging them while they are still in the pack (with lots of cooling)? Good luck

 

a youtube that has charger setting at the time I link at.

hopefully you'll be able to easily convert the CQ 3 settings to your hobby charger.
keep watching for what charger data after cycling looks like for usable cells and ones that are questionable or worse - and even more tips and tricks.