2001 Prius battery problem...replace cells?

[lutung]

Hi,

I have heard that it is possible to replace the individual cells in the hybrid battery. Is this true?
If so, if anyone knows of a place in the central florida area that can test the cells and replace them,
I would be forever in your debt : P Other than the Toyota dealer in Gainesville. They are trying to
charge $3000 for a whole new battery! I heard they can be replaced for around $100 a cell.

Thanks!!!

[ken1784]

<div class='quotetop'>QUOTE(lutung @ Jul 27 2007, 10:38 AM) [snapback]485867[/snapback]</div>

I have heard that it is possible to replace the individual cells in the hybrid battery. Is this true?
[/b]

IMHO, I don't think so.
Regarding to my experience about NiMH and NiCd battery, they are connected in series and should have matched characteristics, such as manufacturing lot, ages, internal resistance and so on.
http://www.tjcells.co.uk/prod.htm

Ken@Japan

[Joekingiam]

[quote=ken1784 @ Jul 27 2007, 10:39 AM) [snapback]486092[/snapback]</div>

IMHO, I don't think so.
Regarding to my experience about NiMH and NiCd battery, they are connected in series and should have matched characteristics, such as manufacturing lot, ages, internal resistance and so on.
http://www.tjcells.co.uk/prod.htm

Ken@Japan
[/b]

Hi,
I am in the same boat you are with my 2001 Prius. I have 1 or 2 bad modules as they are called.
The cells you mentioned are what are inside the module. [6 x 1.2]] 7.2 volt module.
I am searching now to find a way to buy a main battery used, salvaged cheap and remove modules or buy new modules approximately $60 ea. and try to recondition it myself. DO NOT ATTEMPT THIS IF YOU ARE NOT EXPERIENCED WORKING WITH DC AND AC VOLTAGES.
Joe

[bwilson4web]

Hi,

<div class='quotetop'>QUOTE(lutung @ Jul 26 2007, 08:38 PM) [snapback]485867[/snapback]</div>

I have heard that it is possible to replace the individual cells in the hybrid battery. Is this true?
If so, if anyone knows of a place in the central florida area that can test the cells and replace them,
I would be forever in your debt : P Other than the Toyota dealer in Gainesville. They are trying to
charge $3000 for a whole new battery! I heard they can be replaced for around $100 a cell.
[/b]

Ken is pretty accurate about the battery and trying to replace individual modules. This is not an 'off the shelf' item. Now if you have an engineering friend handy with the right set of tools, it might be possible to rebuild a battery pack but it would be pretty expensive labor.

BTW, I saw an Ebay vendor with a battery pack for shipping for about $1.4k earlier this week, which might be another alternative. Of course you'd have a hard time getting the local Toyota dealer to install it.

I snagged a battery from a salvage but I plan to do my 'electrical engineering' tricks and make sure the cells are in good shape. Nothing gets changed until I test them all but then, this is my fun and not a business. Just something I like to do.

Bob Wilson

[FL_Prius_Driver]

Obviously, sooner or later someone is going to combine cells from different HV batteries and post the results.
Unfortunately, too much will be made out of the success or failure forthcoming. A couple of notes:

Submarine battery experience (and there is a lot of that) show that individual cells wear out at different rates due to location in the pack (the edge cells are cooler than the middle cells). At low SOC, the higher performing cells in the pack start "charging" the lower performing cells all the time. To prevent problems, these cells are jumpered out individually till it is time to replace the entire pack. The HV batteries in the Prius are very long lasting, but they do wear out at some point, and one of the mechanisms will be increasing differences in the cell capacities. So I forsee the following:

1) Someone combines cells and is absolutely dogged by SOC variations and constant TOD failures or,
2) Someone gets lucky and has a combination that works (at least till they post).

Submarines do replace individual cells, but after matching for similar ages in other cells. So this can be done with the right equipment and knowledge. (i.e. It is better than recycling if only a few cells are very bad). Otherwise just randomly combining cells is assured of having quite a few problems.