Charging the 12v battery

Not sure why you'd want to do this - but it is in the manual........

Access is under the hood in the fuse box - there's a big copper block that you connect '+' to (clearly marked), negative goes to any metal surface under the hood... Pretty simple stuff..

 

12v gets charged everytime you drive the car. Just drive it everyday and you will be fine.

Mine was a May 2009 built, no dead battery after 35K miles

 

Your battery is as charged as it's going to get.

 

You worry too much

 

FYI, my car was in the body shop for 7 weeks getting hail damage repaired and the battery was just fine. Note that I was driving it at a minimum of every other day so it was in good charged condition when it went in.

 

JIC, you should know the procedure to check the battery and check it once a month. Especially if you have the battery for more than 3 years. If it's below 12.4V at 60F, you should charge it or. (A fully charged battery should be between (12.7V-13.0V depending on surface charge). It would prolong the life of the battery esp. if you use smart chargers. Charging with the car might not be the optimum for the battery.

Plus, if you have access to a smart charger, it doesn't hurt to top-off the battery once a year.
FYI, The OEM 12V Aux Battery has a 2 year warranty. The Replacement battery has 1 year warranty(~$150 or ~$200 installed). The 2nd Gen Aux Battery is similar to the 3rd Gen. So the price shouldn't vary much.

 

I agree. I've been using a CTEK Multi US 3000, maybe once a month. It has status lights, tells you how the battery's doing, when it's done charging.

Regarding your dealer's inattention: want to bet your temp spare's got about 40 psi (or less)?

 

Which setting do you use, little battery or big battery?

 

The options are "motorcyle" (picture), "car" and "snowflake". I use "car". Snowflake is slightly more powerful, but I read somewhere it is a bit too much of a fast charge, that "car" symbol was best. It goes through a multi-stage charge, first stage "desulphating", something like that. Ends up with a maintenance charge rate, ie: you can leave it on indefinitely if you want.

I like also that it shows orange light at the outset, and then when it's satisfied the battery is fully charged, switches to green light.

 

I have a dead battery report from a Prius bought in May, 2010 with 17,000 miles. In the middle of January, I left for a three day weekend to Chicago. The car was in the airport parking lot. I came back and the battery was dead.

Last week, we had a lot of snow and car was not started for five days. Car started without problem.

It is today days now with temperatures between 0-10 F and the car is in a detached unheated garage. I expect it to start tomorrow.

Any idea why three days would drain it, but nothing since and temperatures even colder?

 

Bad luck

 

One little interior light left on would do it. My kids got me that way once, turned the dome light on in back and left it.

- D

 

I have wondered that too, but I have yet to hit a switch for any light being on.

So far, no re-occurrence and it has been below 0 F at night.

Oh, well.

 

According to the manual the fuse box location is for jump starting. Does the + connection there go directly to the battery? Where is the starting battery actually located?

 

This thread has made me paranoid about leaving my Pri alone for more than a weekend...the CTEK 3300 is arriving today!