G1 traction battery shelf life?

[klodhopper]

Does anyone know how long a totally charged 1st generation battery pack can be stored without totally losing it's charge?

We recently ran across a front end collision casualty that had a good battery pack in it and purchased it for a really good price. I haven't had any problems with our pack as yet, but we are now over 104K and may look forward to problems in the future. We look forward to storing it for a while, and could use some pointers.

If we have to, we could swap out the pack with ours ever so often...an actual afternoon job, if it came to it. It's not a very technical, just a little bulky to get in and out without 2 people. We removed the one we bought in about 30 minutes with no problems at all.

We've searched the forums for a solution to a HV "maintainer", but it looks like there are currently no options available. Has anyone explored this option further, or have we all opted to just get one when we need one?

Is there a cut-off for the voltage on the pack that would be usable to determine the necessity to install it and recharge it, or should we consider just changing them ever-so-often to keep them both topped off?

[Patrick Wong]

I think it would be a good idea for you to swap the salvage battery pack now, so that you can confirm that it actually works. Also, how do you know what charge level the salvage battery held when it was removed from the donor vehicle?

Toyota has a TSB on battery maintenance, which suggests that hybrid vehicles should be started every two months and left in READY for 30 min to charge up the traction battery.

If you have a power supply that can provide ~320V at 0.3A, then you can try bypassing the system main relays to charge the battery pack directly. However this can be dangerous if the battery pack overheats, as the modules may explode.

[klodhopper]

The battery pack was all but fully charged when removed from the vehicle. I haven't removed the battery ecu from the end of the pack yet to get to a point to be able to check voltages as it is being stored. Yes the battery was "hot" and the 12v battery was jumped in the vehicle to verify mileage and state of charge. I guess the best way to use this battery pack is to install it and run it as it is, correct? I'll still be facing the same problems with my old pack when I install the salvage one, that is, how long can the pack be stored without it getting too low to start the ICE? Where can I effectively access a test point to monitor the battery pack's condition through storage, and what criteria should be used to maintain them both in a good shelf-stable condition?

[tochatihu]

klodhopper, you have already done the HV battery assembly removal and know the job. If you decide to measure voltages or do charging outside of the car, a very different set of skills would be required (and I don't claim to have them). I suggest that you are a perfect candidate to HV battery 'swaps' on 6 month intervals or so. When you install the other, get into 'ready' and set the parking brake and push both the other pedals to the floor in "D" or "R". Then you will be force-charging, and will top off the HV in 5 minute. 15 minutes. Something like that.

Store the battery as fully charged as possible. Very early Prius speculation was that self-discharge takes 6 months. We really don't know. You, as a battery swapper, could fill in some knowledge gaps by seeing what the battery charge display says after 6 months or other experimental periods.

Anyway, self discharge rates increase with temperatures. How big is your refridgerator?

[klodhopper]

Refrigerator?...I think we live in one...here in the Mtns. of Colorado. Doesn't get too hot here, gets over the century mark every 2-3 years or so for a day or two. That said, I suppose it should shelf pretty good here. I do see the logic of exchanging the packs every 6 months.

I suppose we wouldn't worry about our pack that we take out if it's fully charged. We'll take a day in the future to swap the packs out and go from there, maybe even keep a chart on battery condition on a weekly basis and find a comfortable test point to monitor the battery voltage. I just want to be prepared for a big ticket repair before it happens since the vehicle is over 100K and out of warranty. The current pack seems to get a real workout here in the mountains, and I'm concerned for not only the mileage the current pack has on it, but all the deep-cycling that it's been doing. 1st Generation packs are getting expensive, and we had to take advantage of getting while we could. I actually will look forward to cannibalizing the 2 packs and possibly building one good one later. The rest of the car seems to be doing great so far. It seems to be a real test on the technology here, even as a 1st generation Prius. I'm just trying to keep the "baby girl" going as long as possible while gas prices are high and can't afford a new one yet.

Appreciate the help...

[Patrick Wong]

Originally Posted by klodhopper

...The current pack seems to get a real workout here in the mountains, and I'm concerned for not only the mileage the current pack has on it, but all the deep-cycling that it's been doing. 1st Generation packs are getting expensive, and we had to take advantage of getting while we could...

Yes, I also noticed that salvage Classic battery packs currently seem to be going for ~2/3 of a new battery, which seems outrageous to me. This is evidence that out-of-warranty failures equal or exceed the number of Classic Prius that are being totaled due to a severe accident.

What was the odometer reading and model year of the donor vehicle?

I agree that mountain driving will stress the traction battery more than flatland driving. I live at 1,100 ft elevation and commute to sealevel. Out of three Toyota hybrids, I have lost two traction batteries so far: the 2001 traction battery died at 60K miles while the HiHy 4WD-i battery died at less than 30K miles. The 2004 battery has been OK so far, at 51K miles; but I note that it frequently shows eight green bars of charge, and I don't know whether this is a leading indicator of a future problem...

Regarding periodic tests, you would probably have to open the case to measure the module voltages. As I previously mentioned, Toyota's conservative advice is to recharge the traction battery at least every two months. You may choose to do the battery swap at longer intervals, in which case you'll be entering uncharted territory.

One issue that would be worse than a traction battery failure would be a transaxle problem. The occasional Classic will suffer such a failure; I'd suggest that you change the transaxle fluid periodically (say at 30K mile intervals), in an effort to prolong the life of that very expensive part.

[klodhopper]

The donor vehicle was a very well kept 2003, with 58K, just used around the Denver area.

Yes, there are some "predatory" junk yards selling on flea-bay for $1500-$1600 for these packs with almost the same mileages as the one I bought. They always make you feel you're being done a favor as well.

I have recently noticed a lot of 50Wh markers popping up more than usual, and have gotten suspect of the pack. Although, there are 6 ways out of our high Mtn. valley here, and only one is somewhat downhill. The rest is over Mtn passes of 10K+.

The transaxle oil is scheduled for replacement this month, as soon as I can get parts from our local Toyota dealership which is about 90 miles from us. I'll change it myself, just a small job as well. Just been polishing up on the finer points of changing the oil and cleaning the pan and checking the residue for any "extra parts". Have a parts list for ordering already. Most all of our other vehicles are high mileage as well, but as a 30 year veteran of bruised knuckles, I look forward to keeping her in good shape.

[rapidroy]

Hi everybody, I am new to this forum, been a mech tech all my life about 60 years, I am 67. Just bought a 2001 Prius with a (Toyota says has a bad drive battery). cell# 18 bad. Code P3006. Has aneybody out there ever tried to change a bad cell in one of these batteries? I am considering taking the lid off the battery and looking for a corroded terminal or loose connector. I know about all the warnings on high voltage and wouldn't recomend aneybody trying it without experance working with high voltage. I worked in a missle battery shop back in the sixties and we rebuilt the high voltage missile batteries. Changing bad cells etc. This car also has the stalling problem. The previous owner ( I am not in possion of the car yet, but the check is in the mail and I will haft to get it shipped). Says twice while going about 55miles an hour the car seemed to go into neutral, so I puled over and restarted the engin and then it drove fine again. Aneybody had a problem like this and found the fix? Seems to me the shifter switch could be bad or a relay is droping out. However I have absulity no experience with Hybrids. Dose aneybody have any help for me? If so thanks in advance. Racing Roy (I also drive a race car on dirt tracks.)

[Optimus]

klodhopper,

can you describe the removal and re-installation process of the battery? I have yet to read a post about anyone actually swapping the battery themselves. If my battery ever goes, I will want to attempt swapping it myself too.

[Patrick Wong]

Originally Posted by rapidroy

...cell# 18 bad. Code P3006. Has aneybody out there ever tried to change a bad cell in one of these batteries? I am considering taking the lid off the battery and looking for a corroded terminal or loose connector...

This car also has the stalling problem. The previous owner ( I am not in possion of the car yet, but the check is in the mail and I will haft to get it shipped). Says twice while going about 55miles an hour the car seemed to go into neutral, so I puled over and restarted the engin and then it drove fine again. Aneybody had a problem like this and found the fix? Seems to me the shifter switch could be bad or a relay is droping out...

Hi Roy,

Yes, you are on the right track by opening the case and looking for electrolyte leakage and bad connections. DTC P3009 would be evidence of a leak that is bad enough so that the traction battery voltage is leaking to ground.

You will probably find that the module #18 needs to be replaced, which can be verified by measuring the voltage of each of the 38 modules. Then you'll have to find a replacement module, which will not be easy since salvage Classic traction batteries are scarce. Bob Wilson is a regular on PriusChat, and if you contact him via PM he may be willing to sell you one or several salvage modules.

Also note that if one module has failed, other surrounding modules may be subject to near-term failure due to likely overheating of the failed module that would affect its neighbors.

The other issue that you mentioned about the car going into Neutral is more troublesome, especially if warning lights do not appear to show that a DTC has been logged. If no trouble code is logged, it will be difficult to diagnose the problem. My guess is that the hybrid vehicle ECU is being flaky.

I hope that you did not pay much for this car that has two serious problems.