Gen I main batteries

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.

 

I recently bought a Gen I to restore.

It had a new battery at 150K miles, and it presently has 250K miles on it, so it presently has 100K miles on its second new battery.

Performance is certainly acceptable, but not earth-shaking.

It is my opinion that Toyota was beginning to get most things right with the Gen II, and it finally got all things right with the 2012 Gen III, and that the Gen I was simply a warm-up to the Gen II which, in turn, was a warm-up to the Gen III.

Who really knows what the forthcoming Gen IV will be? Some say the body will be shared with the Camry, but I think that would be a mistake, just as the Gen I body was similar to the Corolla, and that it proved to be less then adequate, although there are still some Gen I "believers" out there.

Should I get as many miles out of my 2012 Gen III as I have on my just-acquired 2001 Gen I, I will very likely be 95 years old, then (I am within five months of being 70 years old, now).

 

Hi - Roy from Canada here --- I have four 2001 prius cars - I have purchased them over the last 2 years . They have 200,000 to 300,000 Km on them. When purchased they all had high voltage battery problems that were easily repaired myself. The ideal solution (when the Gen1 battery shows problems) is to have the battery rebuilt with 38 generation 2 modules (new would be best but used if not). The Gen2 modules are stronger then Gen1 and will last longer then the original Gen1 modules. That being said 3 of my cars are still running on the original Gen 1 modules - I gave them new life by doing a discharge and charge process with RC chargers.