Please refer to the following image:



The above was recorded using a Snap-On Ethos Pro 17.2 and evaluated with ShopStream.

A discharge test was conducted using headlights, rear defrost and A/C to obtain a relatively constant current of 10-11A.

8 graphs were selected for readability. Inclusion of additional block voltages was visually cumbersome.

Voltages for blocks 1, 6, 9, 12, 15 and 20 are the top six plots.

The plot of current is shown at the bottom left with the SoC at the bottom right. Each graph is to scale, and all share the same horizontal axis (time).

The cyan vertical line on each chart is shown shortly before the engine restarted. The values of each graph at that moment are shown in the table at the upper left.

As one can see, the outer blocks (1 & 20) are relatively high and very near one another at 14-4-14.5. As one progresses to the middle, one sees the voltages tapering to their worst near the center (#9 and #12) at 12.6-12.7. No cells have failed; however, this "tapered" pattern of block voltages with the dip in the center is indicative of widespread battery damage with the blocks near the center likely possessing only 10-15% of their rated capacity. Had I been able to plot all 20 block voltages, all 20 would be spread through the voltage range.

Consumer based means of recording data (Torque Pro) have had significant issues with data rate resulting in block voltage deviations being exacerbated. I saw no evidence of that with this tool. I am 100% confident in the accuracy of the results.

This battery can only be repaired by complete battery replacement or replacing all 40 modules.

I will conduct a repeat test after the modules are replaced with 40 new modules.

 

I had originally resigned myself to just ****-canning the modules, but I decided to test them.

Resting voltages ranged from 7.70 to 7.90 with the highs at the end and a STEADY progression to the lows in the middle - Confirmation of widespread damage.

I tested the as-removed capacity of 21 of the 40 modules including samples throughout the pack. NOT A SINGLE MODULE IS USABLE:


"pos" is the position counted FROM the battery computer (opposite the fan). This is my own convention and may not reflect the 1-20 block voltage order.
"DC1" is the as-removed discharge capacity. As you can see ONLY one was above 1000 vs. a rated 6500. If this was a NEW pack, these numbers would be around 4000.

The test results are 100% confirmation this battery is COMPLETELY SHOT. "Just replace the failed module" is a fantasy. There are 40 failed modules due to widespread damage that can't be addressed with reconditioning or any other method.

 

Repeat of test following replacing all 40 modules:


As one can see, at 43% SoC under a 9.1A load, the same blocks are 15.3-15.4. The current is lower due to the overall pack voltage being higher (less current is required to get the same power), and it being notably cooler where the A/C had a lower power demand.

 

Do you have a theory on why these packs are so poor and can never be reconditioned like the toyota stuff?

Generally, in my studies, the hierachy of reusable cores for reconditioning from packs that have generated a P0A80 or P0AC4 (ETC)

1. Gen 2 Prius, Gen 06-07 GS450H
2. Gen 1 Camry/Nissan Altima
3. Gen 2 Camry/ES300H/Avalon/2011-up gen 3/HS250H
4. (Almost always useless) Tahoe/Yukon/Escalade/Silverado/Sierra

Would love to get on a phone call with you eventually my man, doing over 100 packs a month out here in California, would love to exchange some data, found some pretty interesting stuff.

-Cole

 

Here's my list:

1. Gen 2 Prius.
2. Nothing else can be reconditioned.

Every. Single. Other. model has an 80-100% failure rate. I don't even bother anymore. The RARE exception is the occasional Camry that lived outside of Phoenix its whole life. I had ONE 2015 Prius that was about 80% recoverable - it was a privately owned discount cab with 170K miles on it in two years. It was running all the time with the A/C on all the time.

All generation 3 hybrids (everything but the 04-09 Prius) use their batteries more aggressively, and the Gen2 Prius is the only model with a decent cooling system. They screwed up the cooling system on every other model.

Concerning the GM hybrids, there's a user on this forum that claims to have insider information. It was a combination of both Panasonic and GM making poor choices.

From a user perspective, the GM pack failure criteria is so permissive, you have no idea there's a problem until it codes and starts running like ****.

100 a month? That's my annual rate.

 

Its definitely the case in Arizona, for sure, especially with that sitting heat. That's insane man.

 

Reconditioning is a bear here. Very common for the typical Gen2 pack "good" modules to only have ~2400mAh of total capacity. WTF was I thinking? sheesh.

 

I have 4 service vehicles and all of them have 3.5AH (well-balanced) packs and they have lasted an entire year so far. They get driven at least 1500 miles weekly. Good stuff.

You can REALLY get this stuff to last well if you are meticulous and have a great core supply. One of the only nice things about california is the **** core supply lol

 

what about the 48 volt hybrids i.e GMT800 series the batteries used are Lead acid...


I suggest if you want GOOD MPG just get a 4.8L I was able to hypermile 22mpg out of my 2006 long bed silverado ( 4.8L non hybrid..) I all ready found a buyer to dump my hybrid onto they said they would pay the price i paid so i will not lose any money on it(including the cost of the parts i bought for it...)

what a pain that was to park though

i'm going to get another tahoe but a 4.8L though non hybrid... don't get the v6 silveraos they can barely get out of their own way I used someones v6 and it could barely go 60mph with the peddle to the floor it was like driving a Geo metro