Young in mileage, old in chronology, how worried should I be?

Don't worry...I got 265k on my 2005, and it is still running fine. I just have to watch my speed when climbing a hill. Get a Scangauge so you can really monitor the HV battery. If your charge goes down to less than 40% during a climb or heavy AC use, than you need to keep an eye out for the battery. Also, one can get an HV battery for about $1500.

 

with only 53000 miles, you should not be too concerned with the mileage. The battery will eventually need replacement and you probably should buy a new battery if you are looking for another 7 years of service.

another reliable option could be getting a gen3 battery pack and swap the modules into your gen2 car.

 

If you're so concerned then get something else. The Prius whilst reliable can be expensive if certain parts fail outside warranty. If that will cause you significant issues, then seriously consider something different. Just choose wisely.

 

i would sleep like a baby, time has little effect on the battery. there are thousands of '04's on the road with the original battery and many with a lot more miles too, including my neighbor. '04 was a very strong year imo.

 

Put it this way, My 2001 with 130,000 miles, is still on the original battery but, battery life has a lot of dependent factors. I live in a mild climate, I don't strain the battery by going up mountains etc. If you're battery is good now and you learn as much as you can about the Prius and how to "baby" the battery, there is no reason why it can't last another 4-5 years but there are of course no guarantees on anything.

 

The energy BAR gauge is your friend when it comes to babying the battery. The best advice is to always allow the engine to run for 30 seconds when cold, particularly if you start off climbing. I can end up at the top of my hill with a "full" 6 bar blue gauge or an "empty" 2 bar purple one, solely determined by whether or not I do that. Leaving at another location where there is no hill, I do not bother. The gauge will let you know if it matters. I'm one of the '04 high mileage owners. I've put 50K on mine in two years and am at 248K now with a "normal" acting battery. With your car it will be hard to say. If it was driven regularly, all is well. If it sat for periods of time, less so. This is more critical with an Insight than a Prius, however.

I say "full" and "empty" because there are eight bars meaning that 8 and 0 are also available. The control system tries to keep things between 6 and 2, however. The less swing, the healthier things are, be it the battery itself, or your personal driving habits. Using the air conditioner in heavy traffic will tend to cause a great deal of swing. Actually, stop and go traffic will do that even if the AC is off. It's considered normal driving but obviously works the battery a bit harder, an area of "interest" for we elderly battery owners. I stop short of saying "concern".