I got my 08 HyHoe about 3 years ago and I have never been able to go over 10MPH on battery mode unless I am going down hill and every couple of months I have issues with taking off from a standstill as the rpm's increase, but I don't move. I notice this happens most often when I am going slow, but then stop suddenly and then take off again...much like you move up to a stop sign from being the #2 car...move up, stop, go. Since I bought it my Hwy mileage has been about 20 HWY and City is about 18.

A couple of times, infrequently, it completely stalls out and I have to restart it. During these events, it throws the POAC4 and PO61B. I have cleaned the HV Bat screen of any obstruction (which there was some).

I have recorded my driving since yesterday and attaching in hopes someone with more knowledge can tell me if the battery is about to go.

The log starts out at night (air con going and lights one) and I believe rows 246-279 are where I got about a 1/2 miles of driving on only the HV Bat (about 10MPH) before the I hit an incline and the gas engine kicked in. About a mile later, around 285-310, I pulled into a school parking lot that had a slight decline. This is when the HV Bat had some cells down in the 11 range, but stayed in AutoStop.

The Next Day
Rows in 560-range is while I was in the drive-thru and I actually had the high rpm, but the no go occurred.



Any comments are appreciated!!

 

Your taps don't look good, but it may be a symptom of the sampling rate. I'm seeing points every 5 seconds, which is a useless rate for diagnostic purposes. Can you increase the sampling rate to something closer to 1-2 times per second?

When you look at the values around line 800 (43:58 to 46:18) where your current is a pretty consistent ~10A with the engine off (A/C?), your voltage taps are all over the place with deviations up to 2V.

Line 572 where the current is a constant -0.05 for about 7 minutes with your aux voltage at 11.3V, your deviation is 0.8V, which is terribad, and there is a range of values from 14.5 to 15.3 without any obvious outliers. I would not attribute this to sampling since all block voltage readings do not change.

If this were a Toyota, you would have coded long ago due to diminished battery capacity.

If the battery data are accurate, IMHO, your hybrid battery is total junk.

 

As poorly and as many posts as I've made, I have not been able to articulate it as well as dawgfan1606, but this is EXACTLY my problem.

 

Again, if the above pack data is an accurate representation of the actual battery block voltage levels, that pack is junk.


If your block voltage levels look like that, then your pack is junk regardless of what the 'hybrid expert' said.


personally, I would ask him for all of the data he collected during his testing. If he didn't/won't provide it to you, he didn't do the testing he claimed.

 

He's got it. He's supposed to be coming on here to share...

 

Hmmm. That seems odd. Why wouldn't he just give you the data?

 

I have no idea. I never asked for it.

 

Keith - I really appreciate you looking at my data and your insight!!

Ok - I have more data for at least every second during a 5 mile trip. It includes driving about 45 mph on cruise, a brief stop light and ends with me going into Auto Stop as I entered my neighborhood. I agree that things aren't looking good.

My next question, are all of the cells going bad? Does it make sense to get 40 cells of Prius Gen 2 and rebuild it myself (I am able to do this kind of work)? Are some of the cells still good? I understand this battery is going on 10 years old and my novice look at the data shows the battery wearing out pretty evenly across all of the cells.

In you experience, will this gradually continue to decay or will one day a cell just die and I'll have a sudden issue? I'm trying to determine an immediate need or if I can push the expense out about 6 months. Other than the infrequent, occasional stall and not being able to go over 10mph on battery, I'm not having any issues.

ALSO - does battery reconditioning really work - like The Hybrid Shop?

 

Please see the attached.

In the Current, SoC and dV chart, you can see that for currents inside of ±20A, the gray line representing the maximum block voltage deviation routinely exceeds the red line (0.3V). This is bad.

Of note is that there seems to be some tendency for dV to narrow as the drive progresses.

In the Current, SoC and blocks chart, I have identified 3 peaks. As you can see the peaks start to clean up as do the valleys as the drive progresses.

Both charts suggest that your pack is suffering from:

1. Varying degrees of self-discharge (SD) within cells/subpacks. As they sit, even for short periods of time, they lose their charge at high and varied rates.
2. Gross imbalance resulting from #1.

This level of SD is extremely atypical of Toyota cells/subpacks.

This is typical of Honda NiMH "D" cells (also made by Toyota) subject to extreme heat AND Ford Escape Hybrid cells + heat.

The following power supply:

http://www.mouser.com/Search/Product...709-LPC150-350

could be used to slowly charge your pack to full and balance all cells at 100%. You could then use 3 light bulbs wired in series to DISCHARGE your pack to progressively lower levels over a long period of time followed by a very long charge (24-30 hours). The pack would need to be cooled in a way that simulates its normal cooling system operation to ensure the pack doesn't overheat.

Steps:

1. Charge for 24 hours
2. Discharge with 3X 100W bulbs in series to 240V, record discharge time to 288V
3. Charge for 30 hours
4. Discharge with 3X 100W bulbs in series to 192V, record discharge time to 288V
5. Charge for 30 hours
6. Discharge with 3X 100W bulbs in series to 192V, record discharge time to 288V.
7. Charge for 16 hours
8. Install

A harbor freight cheapo multimeter in 10A mode in series with the charge/discharge would allow you to compute charged/extracted capacity over time and actually estimate pack health.

The above is similar to the Hybrid Automotive reconditioning process used for Honda and Toyota hybrids.

Replacing all 40 modules would likely be a comparable cost to a new pack. You would also have no idea if the modules you purchased were good or not.

Testing each individual module will require confirmation of capacity, SD and internal resistance with load testing. In short, you're going to invest a lot of time and/or money into the effort.

The above process will take you about a week and cost you about $50. It will either work, or it won't.


EDIT: I have nothing nice to say about the Hybrid Shop and its affiliates based on direct personal experience and knowledge of their franchising practices and the equipment they use. the process I describe above will give you results at least as good as any Hybrid Shop affiliate you can find that will ACTUALLY agree to recondition it for you (most don't anymore because it's a horrible model for a garage).

 

EXCELLENT information. So, that I completely understand. I can leave the HV Battery in the truck (removing access panel to get to the + and -, connect the LED pwr supply to the + and - for the mentioned charge times (which should get the pack up to 300v). Once it is reached, discharge until voltage reaches what you show, BUT record the time it takes to go from 300v down to 288v. And have a fan constantly blowing over it to keep the battery pack nice and cool. Is this correct?

THANKS!!!