I am extremely happy with my Prius but one of the dealerships I visited early on during my search told me that for the 2007 model, Toyota split up the NiMH hybrid traction battery pack into modules. His point was that if and when the battery pack needs to be replaced, only the bad modules will need replacement. According to him this would be a substantial cost savings. BTW... this came from the sales manager of this dealership in Maryland which I ended up not being able to work a deal with. I already know the battery should last a long, long time but is there any truth to what he said or will the whole thing need to be replaced?
<div class='quotetop'>QUOTE(jackovalltrades @ Mar 30 2007, 08:59 AM) [snapback]414832[/snapback]</div> Owners manual mentions separate packs, I think 6 or 9 or something like that. However, replacement depends on the mode of failure of the pack. If it is normal aging I would assume the whole battery would age at the same rate and so all would be replaced at once. If it's some other type of failure of a pack, then you might get away with replacing just one. In my experience as a ham radio operator, all the batteries in a given application will age at the same rate. But there is still the chance of a different failure mode for one of them, in which case I would assume you could get away with replacing only the faulty one.
<div class='quotetop'>QUOTE(abq sfr @ Mar 30 2007, 11:18 AM) [snapback]414837[/snapback]</div> Is the separate pack replacement new to the 2007 model year?
Since this "info" comes from a dealership sales manager, I'll bet it was only intended to reassure the customer. Just for grins, let's assume that the 2007 battery pack really can be replaced in separate pieces : the service manager at that same dealership would probably say "Yes, we can replace just the faulty component but it's always better to replace the whole thing." Hopefully someone will have some solid references on this matter..
The battery has been modularized since '01 or earlier. Nothing new. However as a general rule, most dealers replace the whole pack. More profit :-(
Yeah, it's a whole bunch of 7.2V packs strung together in series. A particularly industrious person could take the thing apart and look for the dead cell or cells. The only tricky part (assuming you're OK working around high voltage) would be re-establishing a balance across the entire pack. I'm pretty sure they all need to start out very close to the same state of charge in order for the pack to perform properly.
28 modules of 7.2 volts each. Toyota's official policy is that the modules are not to be individually replaced, mostly for the reasons mentioned of different capacities/charging abilities. If there is a delta of more than 20% between pack groups the battery ECU throws a code. However that does not mean it has not been done by some people. Wayne
Yes, they are modular and can be dissembled, 28 of them in the 2004-2007 model. But I'm sure that Toyota doesn't want dealers opening up the battery box. It's built in such a way that it can be disconnected and replaced without ever seeing those modules. The cells, contactors, sensors, and BMS (Battery Management System) computer are all replaced as a single unit. BTW, salvaged packs go for about $500 which is probably what they cost Toyota. Anyway there's a 150K mile warranty on the hybrid components so it wouldn't cost you a thing. Even after that Toyota might just do it for free in order to get the battery back for research, it sounds like the batteries are lasting at least 300K miles from what I've heard. Anyway it's interesting to consider what each module might cost... maybe $15... L8r Ryan
<div class='quotetop'>QUOTE(D0li0 @ Mar 30 2007, 03:51 PM) [snapback]415019[/snapback]</div> I didn't put a lot behind his comment figuring he was pushing for the sale. If it lasts 300k miles then great cause I know the rest of the car won't last me that long.
If your mileage is low each year, will the battery packs die after a certain number of years. I think it will take me 10 years pls to get to 300k.
<div class='quotetop'>QUOTE(jackovalltrades @ Mar 30 2007, 06:13 PM) [snapback]415220[/snapback]</div> Hmmm ... don't be so sure of that. Have you ever owned a Toyota before?
