Understanding battery life and issues

Are you talking about the battery display on the energy monitor? If so, that's not the 12V. That's the big hybrid battery. If you sit in traffic on a hot day with the A/C running it will deplete very quickly. It takes a lot of power to cool a hot car.

That said, if you are on the original 12V then it might be time to replace it. The two options I know of are a new OEM battery from the dealer, or an Optima yellow top and associated conversion kit that elearnaid sells. It's a tiny, unique battery so you can't exactly buy it off the shelf at Sears.

 

No, it doesn't necessarily need to be turned off. It's just that running it, esp. on a hot day puts a big drain on it compared to not having it on.

As I posted at http://priuschat.com/forums/gen-iii...3-same-prius-not-same-mpg-11.html#post1146128

Using the AC helps w/cooling the HV battery. The intake is the vent next to the passenger side rear seat.

I don't know of an easy way to check in the car if the HV battery has been replaced, but I find it highly unlikely that it has as it's warranted for 8 years/100K miles in your state (10 years/150K miles in CA and other CARB states) and not many people have had failures on 2nd gens prior to either warranty period. If it were replaced for some reason, I'm sure the previous owner would've had it done under warranty.

You should able to see the work done by dealers on your car by registering at http://www.toyota.com/owners/ and putting in your VIN.

 

You may be asking how to test the 12 volt battery This site sells a replacement battery, they have a technique to test the battery about 6/7 the way down this page, I would test it first thing in the morning.

Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 10

 

you're not having any issues. your car is running normally. there are no signs that either battery is deficient. relax and drive it like any other car. enjoy!

 

The rule is: IF you feel uncomfortably warm, turn on your AC, your HV battery will thank you, too much heat can kill a HV Battery, over time. Don"t worry about what the MFD is displaying, the computers take care of everything. Just drive it. Later as you drive it, you will understand the car better.:cheer2:

 

This is the key answer - read it and take it to heart. You can't hurt the big battery, and you don't have to do anything special to manage it. Stop looking at the battery display and let the car do its job.

Tom

 

No, you can do what you want. I usually crawl a few miles during my evening commute and most days I choose to roll down the windows instead of cranking the A/C. But I'm perfectly comfortable doing that up to ~90F, and I do it for fuel economy more than out of aversion to depleting the battery. (I have a pet theory that this is better for the battery under my circumstances, but it's only a theory and I don't think many around here share it.) Worst case, you deplete the battery and the engine will start running to take the load.

 

welcome. i also appreciate the low gas mileage.