Traction Battery Replacement - Worth It?

Hi all,

I've read some mixed things about replacing the traction battery, and wanted to get some advice here.

I bought a used 2011 GenIII Prius a few years ago and it was great. Looking at the battery indicator, it seemed like the third bar was worthless (it would appear faster than the other bars but would also disappear very quickly when driving purely with the electric engine) but otherwise the battery seemed to have some good lasting power and it was working as advertised.

Now we're a few years, maybe 20,000-30,000 miles later, and a period of about five months where the car was only driven briefly for once a month. Now the third, fourth, and fifth bars on the battery indicator seem to be flakey. They'll largely take the amount of charge that would be expected, but when discharging it'll seem as if there's amazing staying power... and then it's like I suddenly go from a near-full battery down to only two bars and the gas engine is kicking in to charge it all.

I also have a new commute route, which makes it difficult to tell if there's truly been a hit to performance. Under this new route I have to drive up a little mountain and then go down the other way, all of which usually fully charges the battery (and frustratingly results in almost purely using the friction brakes on the final descent). Yet on the way home it's crawling freeway traffic, a 3.5-mile jaunt that takes about 40 minutes, and the gas engine kicks in 1-2 times during that crawl.

While the battery seems to be lasting for about the distance I recall Toyota rating it for (if you were to travel purely on the electric engine), it all gets me wondering if a battery upgrade would be worthwhile. That way I could recover more charge going down the mountain instead of wasting it at the final descent, and perhaps I could handle that freeway slog without needing to use the gas engine at all. I like the look of something like the BeeMax upgrade pack, but they mostly talk about improved handling and performance, not so much improved mileage. I've read some other comments that the computer system in the Prius might utilize even a higher-capacity battery in such a manner that you don't get much benefit from it for MPG improvement, either.

So... what do you all think? The other thought weighing on me is that I'd like to swap to a fully electric vehicle in about two years; much as I hate to burn gas while at a standstill or a crawl, maybe I should just live with the current battery as it is, even if it's not as healthy as it once was, save the money, and put it toward that electric vehicle when the timing is right.

 

Thanks all for the replies. I'm somewhere around 85,000 miles at this point - it was getting a lot of miles initially but we've since moved to a place where distances are shorter (but traffic is a lot worse).

It sounds like it's not worth it to bother with the battery, particularly given future plans. I'll hold off, then. Thanks for the input!