A Sick 2001 Prius

[Patrick Wong]

Originally Posted by john1701a

...6 bars used to be rare. I clearly remember "seeing the blues", telling others how long I could go (days at a time) without ever seeing green (7 bars). Now, I see green several time a day. I'm quite convienced that it is the result of vehicle components loosening up over time...

Hi John,

Has your commute pattern changed, so that you now drive extended periods downhill?

If no, then my evaluation is that the reason you are seeing green bars is because your battery's capacity is reduced. Hence, less energy is required to charge the battery up to seven or eight green bars.

[rapidroy]

Hi, I have a question for someone who has owned a G1 and a G2. I have a G1 and had similar problems as the sick 2001 until I changed the Traction battery. My question is the G2 which has a different indicator than the G1 indicates a lower SOC with a new or good battery than my G1. Before I changed my battery, The green battery indicator would go from 1/4, 1/2, to full battery, up and down while driving. After changing battery's, It stays full green all the time. Is this normal??? Thanks Roy

[gippah]

Here are the codes:

P3006 (Battery levels unusually different)
P3021 (Battery block 11 becomes weak)
P3024 (Battery block 14 becomes weak)

In spite of these codes, however, on the vehicle diagnostic report, all of the batteries are showing close to the same voltage and resistance.

- The voltages on all of the batteries are between 16.17 and 16.42. Blocks 11 and 14 are near the middle, with both at 16.22.
- Resistance on all of the batteries is between 0.020 and 0.022, with 11 and 14 both being at 0.022. Most of them are 0.022.

There is an ECU code of 47030A.

The battery temperatures are between 100 and 113, with the battery inside air temp at 81.

Although bad battery is being reported, from a layman's point of view such as my own the batteries look to be OK. Perhaps this is just an issue with the ECU?

There are a lot of other things on the report but too much to type, so if anyone wants to know anything specific to recommend a course of action, let me know.

[john1701a]

Originally Posted by Patrick Wong

Hi John,

Has your commute pattern changed, so that you now drive extended periods downhill?

If no, then my evaluation is that the reason you are seeing green bars is because your battery's capacity is reduced. Hence, less energy is required to charge the battery up to seven or eight green bars.

Nope, same old commute for many years now. And I have not noticed dropping to 2 bars more often. In fact, that is still a rare occurence.

So... how is capacity measured? I wouldn't expect it to be dynamic (percent of maximum) like that. I'd think it would be a kW value.

.

[bwilson4web]

Originally Posted by gippah

Here are the codes:

P3006 (Battery levels unusually different)
P3021 (Battery block 11 becomes weak)
P3024 (Battery block 14 becomes weak)

In spite of these codes, however, on the vehicle diagnostic report, all of the batteries are showing close to the same voltage and resistance.

- The voltages on all of the batteries are between 16.17 and 16.42. Blocks 11 and 14 are near the middle, with both at 16.22.
- Resistance on all of the batteries is between 0.020 and 0.022, with 11 and 14 both being at 0.022. Most of them are 0.022. ...

The definition of weak is a pair of modules with more than 0.30 volt difference in operation. So your pair:

16.42
16.17
-----
0.25 V. ~= 0.30 V. under load

The test procedure puts the vehicle in a slow discharge mode and during the sweep, the problem occurred.

We can actually map out the module pairs from the control electronics:

P3011 - closest (I need to check my book it may be P3010)
P3012 - next
...
P3039 - furtherest (again, I need to check my starting code)

Originally Posted by gippah

There is an ECU code of 47030A.

The battery temperatures are between 100 and 113, with the battery inside air temp at 81.

Although bad battery is being reported, from a layman's point of view such as my own the batteries look to be OK. Perhaps this is just an issue with the ECU?

These NiMH batteries are something else. The charge and discharge curves are such that it is nearly impossible to use voltage unless you bring down to the lowest state of charge or up near the maximum. Otherwise, they "look" OK. Very, very tricky batteries to deal with.

Originally Posted by gippah

There are a lot of other things on the report but too much to type, so if anyone wants to know anything specific to recommend a course of action, let me know.

You have these options:

1. timely battery replacement using Toyota - expect to pay $4.5K and lose the car for a day. If you can, get the old modules and let me know.
2. find a salvage battery replacement NHW11 - you are buying a 'pig in a poke' and it may be a great deal or a pack just ready to fail. Expect to pay from $500-$1,500 and a day or so of work. Without tools or expertise, a challenge and you may still have just swapped the Devil for the "deep blue sea."
3. HIGHLY EXPERIMENTAL buy two NHW20 packs - very experimental, replace the 38 NHW11 modules with superior NHW20 modules. However, this is an experimental process and likely to be expensive since two, NHW20 packs are needed to make one NHW11 with some NHW20 modules left over. Expect to pay $1,500-3,000.
4. Experimental refurbish the NHW11 modules - an experimental process, this takes about 3 weeks and you must have a second car during this time. You'll also need a work area, a place to keep the car parked, a quality battery charger, MRC 989, JB Weld, patience and a friend and/or hand truck to help you move the 80 kg traction battery out of the car to the work area and later, back. You will be replacing the lost water by; (1) drill two small holes; (2) lay flat; (3) fill one hole with distilled water until it shows up at the other; (4) turn upright; (5) seal one hole with JB Weld, throughly; (6) put on MRC 989 cycles to reactivate electrodes; (7) seal remaining hole and use 'ice cube' trick to make sure it is throughly sealed; and (8) one full cycle to confirm JB Weld seals. You will do this 38 times although we may be able to cut that down to 19. My attempt to reduce it to 13 times revealed a problem with the MRC 989 that is out for repair. The actual labor runs about 30 minutes, once or twice per day, the MRC 989 does all of the work. However, it takes calender time.

Bob Wilson

ps. If you decide to try #3, don't let any of the NHW20 owners learn about this new drain on the pool of salvage batteries. <ssssssuuuuuussssssshhhhhhhhh>

[gippah]

The Prius tech didn't say the same things that you are saying.

He said that the batteries need to be within 1V of each other, not 0.30. In any case, my batteries ARE within that 0.30 anyway.

He also said to NOT try to just replace the batteries, because if the problem is with the ECU, I may just destroy another set of batteries.

He said that the "brake" light comes on and the car revs up because the computer loses control of the car. So when I am braking at that point, I am using the real brakes in the car and not the hybrid brakes. The car revving is due to the extra power in the system going into the engine area instead of to the wheels. This makes sense as the headlights do get much brighter when this occurs.

He said that the car is safe to drive for awhile, but at some point the battery may drain too much to be able to start the car, if the problem is with the battery.

He also said that since the batteries are within 1V of one another that they couldn't see what the issue truly was, but they still had to go by what the error codes were saying.

So which should I go for here, the ECU or the battery? With how he described the brake light problem, that doesn't sound to me like a bad battery could do that, but I imagine that a bad ECU could.

Also ... the price they are quoting on replacement batteries is $2900, not $4500.

[bwilson4web]

Originally Posted by gippah

The Prius tech didn't say the same things that you are saying. ...

Then go with the tech's advice. He is the man on site with the vehicle, diagnostic system and Toyota tech support on speed dial.
...

Originally Posted by gippah

... So which should I go for here, the ECU or the battery? With how he described the brake light problem, that doesn't sound to me like a bad battery could do that, but I imagine that a bad ECU could.

The tech is the man on site with the vehicle, diagnostic system and Toyota tech support on speed dial. I have no interest in replacing him and you've already asked once. Go with the tech and we'll enjoy hearing how it turns out.

Originally Posted by gippah

Also ... the price they are quoting on replacement batteries is $2900, not $4500.

Excellent! Including installation labor? This is a great price break. The last Texan who reported a battery replacement said it cost "$6,000". This is great news.

Bob Wilson

[Patrick Wong]

Originally Posted by rapidroy

Hi, I have a question for someone who has owned a G1 and a G2. I have a G1 and had similar problems as the sick 2001 until I changed the Traction battery. My question is the G2 which has a different indicator than the G1 indicates a lower SOC with a new or good battery than my G1. Before I changed my battery, The green battery indicator would go from 1/4, 1/2, to full battery, up and down while driving. After changing battery's, It stays full green all the time. Is this normal??? Thanks Roy

Hi Roy,

A healthy Classic traction battery will usually show either 1/2 or 3/4 battery icon almost all of the time. I'm not sure why your car is showing a full battery icon (where no black is showing within the battery icon outline).

A healthy 2G traction battery will usually show SOC ranging from two red bars to eight green bars. Usually the green bars are achieved after a period of downhill driving.

[Patrick Wong]

Originally Posted by gippah

...The car revving is due to the extra power in the system going into the engine area instead of to the wheels. This makes sense as the headlights do get much brighter when this occurs...

So which should I go for here, the ECU or the battery? With how he described the brake light problem, that doesn't sound to me like a bad battery could do that, but I imagine that a bad ECU could.

Also ... the price they are quoting on replacement batteries is $2900, not $4500.

Hmm, if the excess power is going to spin the engine, then I do not see how this correlates to the 12V bus voltage increasing (as evidenced by light brightness increasing.) My guess is that voltage fluctuations are evidence that the DC to DC converter is having a problem regulating the bus voltage at ~13.8V.

What is the name of the ECU that requires replacement: battery ECU, hybrid vehicle ECU, or ?

I agree that $2,900 is the MSRP of the battery itself; typically the labor charge will bring the total price up into the $4K range.

[gippah]

Originally Posted by bwilson4web

Excellent! Including installation labor? This is a great price break. The last Texan who reported a battery replacement said it cost "$6,000". This is great news.

Correct, it is a "price break". The technician said that the battery part costs recently dropped to $2900 (though I seem to remember reading that this was the cost at least a year ago). For labor, he quoted six hours, but remember he recommends the ECU and the battery both, and I imagine the bulk of that would be for the ECU. The battery replacement + ECU replacement would be $5200, which is close to what this Texan was reporting and may be what was done to his car.

Originally Posted by Patrick Wong

What is the name of the ECU that requires replacement: battery ECU, hybrid vehicle ECU, or ?

HV ECU.