It was suggested to me to ask some questions on the Prius forum because the Prius has been around a bit longer time than the Hybrid Camry. I looked through the Prius threads but have not found many battery failure stories which is a good thing. I live in Chicago and the weather has been fluctuating a lot lately.

On a Monday my 2007 TCH with 66,000 miles kicked into the gas engine right away. I went to pull out and it bogged a little. I had left no light on. I stopped a couple of times and it bogged each time then gas engine kicked in. I checked hybrid battery display and battery was drained. I traveled 20 miles and battery started to recharge. Three days later same thing except now the warning message switches from "Check Hybrid System" to "Check VSC system" periodically. I take it to aToyota dealership and they said I need a new hybrid battery. There is not one in the US so it will take a few days to have it shipped. It has 100,000 mile warranty on battery so it is covered. Is this how long hybrid batteries are going to last because Toyota is going to lose money on this situation? I hope new battery comes with the same warranty.

 

Toyota Hybrid batteries seem to last 200-250k miles in normal use (mine lasted 194k miles). High miles per year drivers seem to go further on theirs as there are age and temperature issues as well. As out of warranty Prius replacement costs about $3300 (your Camry battery may be different) at a dealer or under $2000 at Re-InVolt (refurbishes Hybrid batteries in NC) this amounts to about $0.01 per mile which is about what my tires cost me per mile (your tires may cost more). If you keep a Toyota Hybrid a long time just budget for a replacement as it is a minor cost of driving a high mileage car.

The new battery will be warrantied by Toyota for 12 months with no limit on miles. If you have an out of warranty problem with your Camry, there is a great independent repair facility about 2 hours away from you

http://www.autobeyours.com

just outside of Indianapolis.

JeffD

 

Thanks JeffD. I picked up the car yesterday and the service guy did say it was very rare and in the twelve years he has been there that mine was the fourth battery to be replaced. He even said two of those cars had been in rear end collisions, so that may have been the problem with those two. I also asked and he stated that the battery will only be warranteed for th remainder of the original 100,000 miles which is about 34,000 miles. It makes more sense that Toyota warranties new batteries for 12 months upon replacement. The car seems to be running fine but it has only been less then 24 hours. Hopefully I will get 194,000 miles out of this new battery.

 

Batteries are "chemistry" and Panasonic, the maker of the Prius NiMh battery has the world's best "chemistry" for that technology. I have been testing hybrids for over 7 years now and have seen very good performance with the Panasonic chemistry.
Further at home I have several Panasonic NiMh AA rechargables. They are approaching 8years old and compared to every other NiMh in that battery size I own, they still out perform them.

I would expect at least 10 years life in these batteries and over 250,000 miles.

 

I agree that Panasonic knows NiMh. But Toyota's strategy for long life (maintain the string of 28*6=168 NiMh cells in my 2004 Prius between 40% and 80% capacity) has a flaw that limits the long term life of the HV battery. There is no effort to maintain cell balance. This will cause the eventual reverse charge on a module which results in a battery failure.

To balance the cells in the string, the battery needs to be taken to full capacity and then trickle charged to bring the cells that are at lower SOC to full capacity. The already fully charged cells will just dump the excess energy as heat (use a low current and monitor temperature). My Supermate DC6 battery conditioner does this with multiple discharge/charge cycles, but can only handle one (6 cells) or two modules (12 cells) at a time. This requires disassembly of the battery unit (Warning! Dangerous High Voltage) and is a long process if you don't have multiple battery conditioners (I only have one).

JeffD