12V battery won't charge anymore

Your Ex has a 2006 with the original 12 volt battery?

It's 2015, time to get a new 12 volt.

I don't think you necessarily need a mechanic...but somebody needs to install a new 12 volt battery.

 

most Prius batteries last only 4 years. You probably just need a new one.

 

This will come with detailed instructions. Optima DS46B24R Optima battery direct fit replacement for Prius 2004 + , Prius v & Plug-in Prius with Instructions

 

Think about it. If there were a free DIY way to keep "dead" batteries working forever, don't you think we would all be using it and none of us would be buying new ones.

A poster just started this post below a day or two ago. Up near the top is a good video on how to change out the battery...or you can pay a garage anywhere from $200-$300 to do it.

But, you need a new battery. Period.
08 Prius Dead. 12 v battery and spare tire under Ice | PriusChat

 

Replacing the battery is a pretty easy DIY. The most hassle free choice would be the OEM battery. There may be a "core charge", basically a small deposit, refunded when you bring them back the old one. A few suggestions:

1. Check the voltage of the new one with a digital multimeter when you pick it up. Should be around 12.6 volt, minimum.

2. Hook it up a smart charger, one that will cycle through a charging regimen, can be left on indefinitely, if needed, 3~4 amp range. Let it run to completion.

3. Unhook neg cable first then positive. Install the new one in reverse order.

4. Clean the cable end clamps, and posts on the new battery. Be careful, the dust is lead.

The only tool you really need is a 10 mm wrench. A 10 mm ratchet wrench might be helpful, too. When tightening clamps on the new battery just don't go nuts, use firm but not heavy tightening.

 

Dude. The battery is toast. Accept it and move on...

 

There is, but it is called car prowl (i.e. break into another car and steal its 12V battery), and isn't legal. And if you get caught, it is no longer free, but far more expensive than just buying a new one.

 

Jason, sounds like your ex just want's you to buy her new battery. She obviously doesn't know how to install one and as you said it's your son, so just do it and teach him how to while you learn how...on the Prius that is. Ex is happy, bonding time with the kid, problem solved.

 

DIY seems to have morphed into

Do it MYself? No, do it YOURself!

 

Sorry but she is wrong.
The odds are overwhelming that the 8 year old battery just needs to be replaced.
Somewhat lucky that it lasted this long.

 

Well, she's your ex-wife for a reason, and apparently lack of automotive knowledge might've been part of the reason! Haha jk. I replaced the 12v in my 2007 with an OEM Toyota (yuasa) battery in under 15 minutes.

 

1. Obviously the 12V battery needs to be replaced now and that will set you back $200 or so. Just do it for your son if not for Julie.
2. Once a new battery has been purchased, recognize that it needs to be fully-charged prior to installation. A new AGM battery should measure ~13V out of the box. If it does not, then put it on a charger overnight, set to the 4A charging position.
3. If the new battery gets to the point where a jumpstart is required, and if you wish to save the battery at that point, it is necessary to fully-charge the battery overnight. Don't think that 20 minutes of driving is adequate for this.
4. Julie needs to learn that it is really poor practice to get into a continued habit of having to jumpstart any car, but especially the Prius. If the jumpstart is done incorrectly you will zap the DC/DC converter within the inverter and that will set someone back four-digits to have the inverter replaced at a Toyota dealer. Instead, keep the 12V battery charged so that there is no need to jumpstart it. This may require periodically hooking up the car to a charger if the car doesn't log sufficient driving time. Maybe that is something you can do monthly, when bringing your son to and from Julie's home.