Gen I main batteries

There seems to be very little discussion of older battery life. I just passed the 105K mark, so it's starting to weigh on my mind. Is this being discussed somewhere that I'm not seeing?

The reason for no serious discussion is the absence of hard data.

Bob Wilson

Some of these failed quite early, which probably led to Toyota's special service campaign to reseal the modules to the elctrolyte inside wouldn't leak out and corrode the connections. Did yours have that work done? It's free.

Some have lasted for more than 300,000 miles in service. Overall failure rate of perhaps 1 to 10%? Known to Toyota; not to us.

Other than SSC 40G (above) there is not much you can do to help, besides avoiding extremely high battery temperatures. If you're curious, have some money to spend and a good Toyota shop handy, they can measure module voltages during charge and discharge cycles.

In the case of gradual battery failure, some have reported falling fuel economy first, followed by warning lights and very poor vehicle performance. Then, the diagnostic codes identify the battery or some other cause.

If you don't want to pay for that test, then I suggest you just not think about it until a problem arises.