Is it better to convert a plug in early in the prius life...

Yes. You'll be growing older! As will the rest of us.

I converted my '05 w/ 45,000 miles and an extended warranty, this Jan. I'm so glad I did. It's a new driving experience. With the warmer weather, I have 200 miles on my current tank and the gas gauge still shows full!(no scan gauge thou).

Driving is really fun again. It's so great driving around with no pollution, .55cents/day, and no foreign oil imports.

The other thing is, you want to get the most use of your L5. So the sooner you install it, the longer use you have. 120,000 is a lot of miles to add a $10,000 upgrade.

And remember, it won't void your Toyota warranty.

That's where I stand. Best of luck whatever your decision!

George

 

Yes, sooner. The battery is expensive and it's supposed to last (say) 10 years. You want the car to last that long after you've put the battery in.

The only significant downsides to sooner are that 1) you'd expect the price to fall and 2) the assertion that the electrical side of the drivetrain can take the extra stress over the long haul is not yet proven. And won't be until a significant number of these conversions hit 150,000 miles.

Given the cost of the modification, I'm not sure I'd convert a car with 120K on it. In theory, I guess you could move it to another Gen II if the first vehicle dies, but that's not clear.

On the other hand, it's not like I've seen a lot of good end-game strategies laid out anyway. If the battery is as good as it seems to be based on testing, there's no way I'm letting my '05 go to the junkyard with the hymotion battery still in it. But I don't exactly have a fixed plan for what to do with it. It's got a built-in charger . so a PRIUPS-type arrangement suggests itself. But I suspect that there's more to the battery controller end of that than I could deal with.

While I'm rambling about end-use of traction batteries, it occurred to me the other day that Prius traction batteries pulled from wrecks are by far the cheapest source of large NiMH batteries around. They seem consistently to run $400 to $600 on Ebay. Which would be something like 35 cents per watthour. Basically, that's a rechargeable for the same price as you'd pay for alkaline disposables.

 

The terrific thing about the Prius is that it just keeps going. Really, the main part that is going to wear out after that many miles is the OEM battery...If you convert your Prius with a conversion that replaces the OEM battery such as the Plugin Conversions (Plug-In Home) kit, then you need not worry about this because it would be a brand new battery.

Also, about the warranty issue: A car company has to prove that the modifications done to the car caused the problem that you are reporting before they can invalidate the warranty. For example, if you converted your car they would have to prove that the conversion caused your AC to break, or your coolant pump to spring a leak. I know that at least Plugin Conversions offers a 3 year warranty on the battery (which Toyota obviously wouldn't cover).

Andrew