Classic Prius Repairs

[tochatihu]

In another thread, a statement attributed to Toyota that the NHW11 battery has a 1% out-of-warranty failure rate:

http://priuschat.com/forums/prius-ma...batteries.html

Obviously this cannot be accomodated by the poll either, but I believe it is the first 'official' statement on this failure rate. Now, if they would be so kind as to offer the same information about transaxles...

[Patrick Wong]

Originally Posted by tochatihu

... Now, if they would be so kind as to offer the same information about transaxles...

Hi Doug,

The general motorist population is not aware that Classic transaxle failures is an issue. Hence there is no reason for Toyota to bring it up.

Interestingly, my little poll does not include any reports of transaxle failures so far.

[rapidroy]

1. 2001
2. 153,000 ebay vehicle purched for $6,100.00 with known bad battery, cell #18 as tested by Toyota.
3. Purchased used battery from salvage yard in northern Alabama, which was from a 2002 car with 107 miles on it for $500 and $130 shipping. When I received the battery I was surprised to find it to be like new and the SOC to be 292V, all Moguls were within .02v of each other.
4. When I received the car, which was in very good condition except for the drive battery, I would clear the code P3006 and it would reset just idling in the driveway. I drove the car around the block a couple of times. The ICE ran constantly and the battery SOC would go up and down from low to full charge. I left the code scanner inserted and reset the code a couple of times and it would shortly reset. My son and I swapped out the battery, took us about 2.5 hours, we could probably do it faster now. We pushed the battery into the trunk area and picked it up with an engine crane. used the same procedure to re install. I might add this would probably take longer, but we had air tools and the bolts came out and in pretty fast and we are both experienced gear heads. After the change the car ran great, I have put about 75 miles on the car and no problems. I have rescanned twice and no codes set.
5. Code P3006
6. $630.00
I haven't looked at the old battery yet. I found another dead battery for $200 and bought it with the thought of using cells to fix the removed battery to ether have as a spare or to sell it. I have been able to charge 6 module's to 7.8V and they have been holding their charge for two days so far. I wish I knew how to load test them, I know there is a lot of elect techs on this site. If anybody knows how to load test a 7.8V DC Battery, please let me know how.

[Patrick Wong]

Originally Posted by rapidroy

... If anybody knows how to load test a 7.8V DC Battery, please let me know how.

Hi Roy,

In general, the way to test a battery is to apply a resistive load and see how long it takes for the voltage to drop down to a specified level.

Regarding the Prius traction battery, I think the best way to test it (given your prior experience in swapping batteries) is to swap the repaired battery back into your car and see if it works or not.

[rapidroy]

Thanks Patrick, What I wanted to know was how to test individual modules before I replaced them. I assume it would be 1/38th of 6.5 AH or if testing two at a time, which is what I want to do, it would be 1/19th of 6.5 AH. I need to know what kind of load tester I need. I have a complete extra battery that had very little charge, about .5V on some cells when I received it. What I have been trying is charging up two modules connected together to 15.5V and using a 12V fishing reel as a load. I was able to run one set for 9 minuets and 46 seconds at .89 to .82 Amps until it reached 10.5V. I have tried two more and they only lasted less than two minutes. I suspect they are low on watter, but don't know if I am doing something wrong. This is something I probably need to talk to Bob about, if I can't figure it out on my own. I am about ready to cut one apart and look at it to see if it is low on watter. If so I will haft to find out how to fill them.

Roy

[Patrick Wong]

Originally Posted by rapidroy

Thanks Patrick, What I wanted to know was how to test individual modules before I replaced them...

Hi Roy,

Each module is rated at 6.5AH. In theory, each module should be able to deliver 1 amp for 6.5 hours before the voltage drops down to a certain level.

Since the modules are connected in series, all 38 modules collectively can deliver 6.5AH. Each module individually also can deliver 6.5AH, but obviously the voltage provided by one module is only 1/38 of the entire traction battery.

The rated voltage of a module pair is 14.4V. If your available charging voltage is only 15.5V, that may be insufficient to sufficiently charge that pair. For example, with my 2001, the traction battery voltage was around 320V when the SOC was around 70+%. This implies that the voltage for a module pair is 16.8V, hence the voltage required to charge may be 17.5V or more.

Since you can only draw 0.85A for 0.16 hour, then you are only getting ~1.3AH out of that module pair. Therefore I would conclude that module pair has insufficient capacity, which might be because the pair was insufficiently charged, or could be that the module pair is worn out.

I hope that you are keeping the modules physically compressed when you are charging them, as they will tend to expand and may explode if they are not physically restrained. You also need to be concerned about the temperature increase as the modules are charged.

Regarding refilling the modules with distilled water, this will not be easy to do. Your challenge will be to reseal any holes made so that the module is airtight and will withstand the pressure increase as the battery is put into service and charged/discharged.

[rapidroy]

Hi Patrick, Your help is much appreciated, could you give me the method you used to get the 1.3AH. I didn't think I was getting that much. I thought I would need to get 1A for 6 hour per module to get 6AH or 12 hours for 2 modules. This appears not to be the case. Any way I recharged the Module I thought might be good and it was over twice as good as the first time. Maybe it just needs to be cycled up and down a few times. The second time around, I only used one Module this time. I started at 7.87V to 5.25V and it ran the reel at .78A to .74A for 28min and 14 sec. I am charging it again to try it again to see if it improves even more. Next I am going to remove 2 good Modules from the battery I took out of the car, charge them and load test them just to get a baseline. I am going to figurer this thing out yet. I don't have any give up, can't do it in me. I certainly would appreciate knowing how you figured the AH. Thanks again Roy

[Patrick Wong]

Originally Posted by rapidroy

Hi Patrick, Your help is much appreciated, could you give me the method you used to get the 1.3AH.

Hi Roy,

0.85A x 0.16 hour = ~0.13AH (not 1.3AH)

So the battery capacity is much lower than expected. Keep in mind that when the modules are connected in series, as they are with the Prius battery, then the current flow is identical through each module. Therefore the AH of each module is identical.

[statultra]

2001 Prius bought new at dealer, 2001
no problems until i took it in for the battery sealing thing, where i would get seemingly random triangle lights.

another 01 we have that we bought salvage
the main battery was low when we got it because it rested for 1 year, in winter and stuff, we had to charge it in order to start the vehicle.
10,000 miles later at 50,xxx miles no problems
no problems, just that one time the inverter water pump failed, resulting in replacement.

thats about it

[Patrick Wong]

I'm bumping this back up to see if more than 32 Classic owners will respond to the poll. Thanks!