Other message sent to communicate intent prior to calculations:

Estimates:

287-245V: 3.71Ah
245-220V: 0.51Ah
220-204V: 0.28Ah

That puts you at a "usable" capacity of 4.5Ah though the portion below 220V is probably not particularly usable.

EDIT:

204-168V: 0.18Ah
168-163V: 0.12Ah
163-102V: 0.23Ah

The total extracted below was 0.53Ah, which is a little over 10% of what you have above 204V. This is very typical in my experience. A small amount of this, 25% might move up into the usable capacity range.

Again, this all assumes that you don't have a marginal or failed cell. Sadly, the discharge data can't reveal this, but your Hybrid Assistant testing can.

Note also my estimate of the discharge with the 200W bulbs is likely conservative by about 10%, so the portion above 220V may be as high as 4.6Ah, which is an exceptionally good number for a high mileage battery.

PRIOR TO DRIVING, I vigorously recommend that you conduct a Hybrid Assistant discharge test in "N" to 40% SoC before allowing the car to start the ICE. This should give you some assurances that the process was successful or not and confirm that you don't have any issues with the 17 blocks.

Good work in sticking with it and gathering the data. It's a great way to estimate capacity and see the improvements with additional cycles.

 

Hi Keith,

Attached are 2 reports, the first one right after the reconditioning (after waiting 1.5 hours) and the second after a couple of short trips. Unfortunately I missed putting it in "N", so the first section of the graph shows it I believe.

Thanks.

 

I'm happy to be wrong about the state of your battery. For my reference, where do you live? You must be in a very mild climate.

I would call those results a smashing success. Anything near the 5Ah range for a 10+ year 100K+ mile hybrid battery is great.

Moving forward:

30, 60 and 90 days: repeat the discharge test and see how it holds up
90 days: conduct an overnight (8-12 hour) grid charge to top the battery off.
Every 90 days thereafter: discharge tests and overnight (8-12 hr) grid charge
Every 12 months: conduct a SINGLE reconditioning cycle (charge for 24 hours, discharge to 163V) [ should restore almost all of your lost capacity.

If at any time the discharge tests show a marked decrease in capacity or significant increase in voltage deviation, repeat test to confirm results. If confirmed, conduct a single 24 hr charge/discharge to 163V cycle.

Essentially, monitor and react. Do not charge or discharge any more than is necessary to maintain performance.

Should you experience cell failure, you can now have confidence in the module replacement option provided you get the modules from a reliable source.

 

I'd like to give you an example of why I'm so pessimistic on Camry packs. The following values are the module voltage readings from a 2007 Altima Hybrid (a re-badged Camry) with 196K miles after sitting for approximately 10 days:


Mod Voltage
1 7.70
2 7.70
3 7.70
4 7.66
5 7.69
6 7.69
7 7.61
8 7.68
9 7.73
10 7.70
11 7.56
12 7.69
13 7.69
14 7.69
15 7.69
16 7.69
17 7.70
18 7.69
19 7.63
20 7.69
21 7.70
22 7.67
23 7.67
24 7.68
25 7.69
26 7.70
27 7.70
28 7.69
29 7.70
30 7.69
31 7.69
32 7.68
33 7.70
34 7.69

This car coded with a P0A80. Which modules would you replace?

 

Thanks so much Keith for all the help, encouragement and hand-holding you did. I will do the steps you mentioned at the specified periods and report back. I have heard of the Camry being very hard on the batteries, compared to the Prius. In the example above, I guess you consider them all below par?

I am in East Central Illinois. I bought the car (in service from 09/2006) from a retired gentleman from Louisville, KY, at 76K miles in 2012. The car has been great. I see 36 MPG on the highway and see ~42 MPG in town when I drive with some P&G techniques. I do have a used 2010 Prius as well bought in 2011. Hybrid Auto told me I could use the Camry charger on the 2010 Prius as well, so that was another reason I decided to invest in the Prolong Value system. Kudos to all the research, etc., that went into Grid Charging in general and all the further research/engineering that went into the Prolong system in particular. I hope I haven't spoken too soon on the Prolong system and that the system will have significantly prolonged the life of the batteries for the good of the environment.

Thanks again.

 

Yes, you can use the Camry HA charger on the 2010 Prius provided you get a harness for the Prius. The Camry charger has a higher voltage output and may result in a slower charge following deep discharges where the pack is at very low voltage.

Given my experience with 2010+ Prius, it is no different (being hard on batteries) than the Camry. They are both "generation 3" hybrids. You should be looking at the battery now. The procedures you applied to the Camry apply to the Prius. I recommend you run the Hybrid Assistant discharge test ASAP.

Concerning the voltages, I can't make any conclusions based on those numbers, nor can anyone else.

What is noteworthy:

Module 11 is an outlier at 7.56V
Module 7 is also an outlier at 7.61V
Module 9 is also an outlier at 7.73V
Average is 7.68V
Average removing the outliers: 7.69V
# of modules in a ±.02V range: 29

Overall, aside from the two "low voltage" outliers, there's almost nothing to indicate why this pack failed.

Let's add a column of data - as-removed capacity, i.e., the mAh of charge stored in the module:

Mod V_i INIT
1 7.70 2130
2 7.70 2041
3 7.70 1921
4 7.66 1123
5 7.69 1090
6 7.69 1123
7 7.61 339
8 7.68 1251
9 7.73 391
10 7.70 295
11 7.56 624
12 7.69 1274
13 7.69 1448
14 7.69 1802
15 7.69 1711
16 7.69 1488
17 7.70 1234
18 7.69 1083
19 7.63 1004
20 7.69 1565
21 7.70 976
22 7.67 1092
23 7.67 480
24 7.68 1527
25 7.69 1572
26 7.70 2107
27 7.70 2149
28 7.69 1939
29 7.70 573
30 7.69 2140
31 7.69 2018
32 7.68 1335
33 7.70 2170
34 7.69 2288

Very healthy modules pulled at about 60% SoC will have 3000+ mAh. Note that a module has a rated capacity of 6500mAh. As you can see, even with good voltage, SEVEN have less than 1000mAh available, and NONE have > 3000mAh.

Adding yet another column, the FINAL capacity after reconditioning:

Mod V_i INIT DCH
1 7.70 2130 4093 X
2 7.70 2041 3755
3 7.70 1921 2857
4 7.66 1123 1695
5 7.69 1090 1611
6 7.69 1123 1773
7 7.61 339 720
8 7.68 1251 1980
9 7.73 391 722
10 7.70 295 591
11 7.56 624 2362
12 7.69 1274 2235
13 7.69 1448 2499
14 7.69 1802 3608
15 7.69 1711 3142
16 7.69 1488 2448
17 7.70 1234 1809
18 7.69 1083 1622
19 7.63 1004 2257
20 7.69 1565 2822
21 7.70 976 1603
22 7.67 1092 1649
23 7.67 480 823
24 7.68 1527 2924
25 7.69 1572 3174
26 7.70 2107 4207 X
27 7.70 2149 4208 X
28 7.69 1939 3979 X
29 7.70 573 905
30 7.69 2140 4049 X
31 7.69 2018 4036 X
32 7.68 1335 2160
33 7.70 2170 4350 X
34 7.69 2288 4555 X

As you can see, many are still < 1000mAh of total capacity, and while one can't see it in the data presented, I have access to other data that indicates further issues. Generally speaking a "good" DIY rebuild will have at least 4000mAh of capacity. Only 8 modules meet that. ALL OTHER MODULES SHOW OTHER CHARACTERISTICS INDICATING THEY ARE NOT RELIABLE. This pack needs 26 new modules. I think most would agree that isn't realistic for most DIY efforts, and without this level of testing, one would never know.

 

Hi Keith,

I certainly wouldn't be able to get to that level testing. May be if one or 2 modules turn up as failed in Load Test reports, perhaps I would consider getting a replacement from HA.

For the 2010 Prius, I do have the harness and I did do a Load Test when you first mentioned about the Hybrid Assistant app to me, as soon as I got the Bluetooth adapter. Attached is the report.

Thanks.

 

Just trying to illustrate how futile the module replacements can be. Note also that your initial capacity was closer to 3Ah on your discharge test - that means that without this reconditioning effort, you would be STARTING with a batter at less than 50% - failure is more likely at that level.

On the 2010 you can see the SoC curve "leg down" towards the end of the discharge. That's a sign of capacity loss, which is confirmed in the report showing capacity about 70% of rated. DeltaV is mostly good.

I recommend a SINGLE cycle with a 16 hour charge (from 60% SoC) and discharge to 134V.

 

Thanks, Keith. I will install the harness in the next week or so on the Prius, perform the single cycle and report back. After the discharge to 134V, should I leave the charger on for 24 hours? Thanks again.

 

Yes, to insure it's fully charged.