Miles on the battery are as not as important as years on the battery. The poll should be rephrased. My battery failed at 14 y/142k mi on my red Prius and at 13 y / 161k mi on my green Prius. The batteries last long but not the lifespan of the car. I expect a car to last 18 years so at 13/14 years when my batteries failed I chose to address the issue and keep driving the cars. I wouldn’t send a car to the junk yard at 13 years but I am afraid with electric cars that will be the case. When an expensive traction battery fails that would be the lifespan of an electric car.
Manufacturers are usually talking 150k miles when talking about a car's lifespan. Which works out to around 10 years for many in the US.
Yes I think your climate is really good for he NiMH battery ... here in Australia we get a lot more hot days well into the 30's and even 40's. There is a Prius taxi in Northern Europe that has done 1 million km on original drive train and battery.
Yes a hybrid battery failure at 13 years is annoying but not a write-off ... but a BEV battery failure at that age is probably a writ-off. What we don't know yet is whether the Gen 4 Prius battery with welded bus bars will last longer. If it could last 18 years that would be a great outcome.
Traction batteries aren't a simple slab of cells. They are organized into subunits. A battery failure can be traced back to a bad subunit, and the cost of replacing that bad section can be close between a hybrid and BEV.
I had to replace my traction battery in my 2004 Prius at 195k miles and 7 years due to one bad cell in one module. I installed a "ReInVolt" remanufactured battery that was working well at 288k miles and 12 years when I traded the 2004 in for a 2016. JeffD
What became of the old battery? Was it sent to a refurbisher to take apart, and replace the bad cell? Whereas a hybrid battery is one unit that would have to pulled out of a car, a BEV has multiple units that can be removed individually. So when a cell goes bad, only one unit needs to be replaced. Which means the cost to repair is only a portion of a total battery's cost in a BEV.
ReInVolt (North Carolina at that time) drop shipped the new battery at my Toyota dealer ($1600) and the dealer installed it for me for $400. I was allowed to keep the old HV battery. I then educated myself and rebalanced the good 27 modules, sold them in sets to 6 different individuals (3 PCe, 3 eBay) to use to repair their Prius HV batteries. A seventh individual (PC) bought my HV relays and ECU to fix her Prius. Total cost $2000. Total sales of salvaged parts $800. Net cost $1200. Not bad! JeffD
You can replace a failed module, however if it's 12 years old then other modules are likely to fail .. so its a temporary fix. Also the labour cost can be significant. The other issue is that increasingly it's likely batteries will be non serviceable. Toyota already welds it battery terminals in NiMH batteries to increase longevity. Tesla have proposed a structural battery to reduce weight and improve stiffness, but I suspect it may well not be serviceable at the module level.
