New 12V battery installed - Easy (almost)

If you have a jump pack, hook it up at the front jump point, I think you'll be able to open the hatch.

Without a jump pack, I think you've got a mechanical release lever, on the wall just below the threshold. There's maybe a little plastic panel has to be popped off.

 

great price, well done!

 

Was just about to drive to the Toyota dealer to purchase a new 12V battery for my 2013 Prius Two (Gen 3) when my hubby, who accidentally left the trickle charger on the past three days, found that the trickle charger said the battery was fully charged and when he measured the charge with the voltmeter it said 13.3. Happy to save the $239 plus tax.

Since I wfh I was already driving less than 7K miles each year but with running less errands during this Covid-19 pandemic and only going out grocery shopping once a week now, leaving one interior light on or leaving the hatchback door ajar appears to really drain the 12V battery quickly. So now I'll regularly check for lights out and snug hatchback door closure, plus leave the trickle charger on more regularly.

My hubby was really looking forward to using this excellent youtube video to install the new battery in the trunk; now he'll have to wait.

 

welcome!

i think if you lock the doors, you don't have to check anything

 

Like everyone on this site who gets a dead 12 volt battery you don’t arm the alarm every single time you get out of the car if you did you would find it would alert you to a light left on.

The bad news is if that 12 volt battery was killed flat by a light bulb it’s probably been damaged by sulphation. As that’s a deep discharge
New car battery’s aren’t half as tough as batteries 30 years ago plus it’s a tiny battery. The fact that it was charged to 13.3 volts is meaningless what you don’t know is will it hold a charge.

Ask your husband if he owns a voltmter we can test that battery. He may just get his wish after all.

Also letting a Prius sit for days on end is really bad for the hybrid battery too. Corrosion will set in.
Try to take it out for a good spin as often as you can. Seeing a lot of hybrid battery issues during covid
Since no one is driving much.
Prius battery’s last the longest on high mileage driven daily cars,

 

Ok eight months later and now the 12v battery has become like the dripping kitchen faucet in "Zen and the Art of Motorcycle Maintenance" to my hubby and I. Based on many posts here in priuschat, I purchased the required AGM battery in group size 46B24R with a full 3-year replacement warranty (not a pro-rated warranty like the current battery sold by dealers). Since we have a mild climate here in SoCal, went with the Duralast Platinum AGM for $200 versus the yellow top Optima AGM for $250, both at Autozone. Out of stock at nearby Autozone; employee tried to push the more expensive Optima saying the Duralast cannot be special ordered. Called a different Autozone and after about 20 minutes the super nice employee found it in stock within about 10 miles; so nice that he even apologized for taking so long (how refreshing!).

Now my hubby gets his wish of following the above excellent youtube video to install the new battery in the trunk.

 

Good call that’s what I’m going for next the yellowtop seem to fail soon as soon as they get out of there 3 year warranty.

but I saw a post the factory battery at the dealer has become much cheaper so going to check that out this weekend.
The words dealer and cheaper have never come out of my mouth before so I think it’s horse hockey I’ll let you know but the duralastis a good choice.

I have changed mine a few times here’s th3 best tip there is 2 black wires that connect to the battery. They plug into the black plastic fuse assy on top of the battery. Take the red plastic cover off and those wires have white plastic clips with a locking tabs depress the tab and they pull right out. There keyed so you can’t mess them up.
When those 2 are disconnected no sparks when you unbolt the battery cables.

bolt it all back up and plug those 2 wires in and your done. First time you go to start the car it will fail. Just shut it off and try again and it will start right up.

 

sorry diplomatic I saw your post in my inbox clicked on it did not realize it was from the g3 forum thought it was a g2 version the battery configuration is a little different on your G3 car. So disregard my 2 wire gimmick.

 

Hubby just installed the new battery but cannot start the car without jump starting it. Voltmeter on new battery reads 10.7. Could this be a faulty new battery?

 

@edthefox5 given the data that most of us that are interested in the subject have about prius traction pack in high mileage prii usually being in better shape than lower mileage prii of the same age, do you think as I do that at least one of the reasons for this is that the gas engine gets used a lot more. Another being the traction pack has more time to equalize/balance and become temperature stable for a much longer time than in lower mileage prii?
My only goal is to appreciate other members take on why high mileage packs seem to always be in better shape than lower mileage prii. (not sure what kind of icon would enhance this post, if any)

 

Yes a higher mileage car usually has a healthier battery for the exact reasons you quoted but that also requires excellent engine maintenance to be worth a crap at 200000 miles.

not many take excellent care of there car most never ever even check the oil.
We see so many flogged to death 200000 mile g2s on this site that were just purchased mainly because it’s rep for being a great little car. It’s the toughest little car ever an engineering marvel really.

2 reasons high mileage g2s are sold
Bad hybrid battery
Whipped engine

take your pick.

 

Returned brand new battery to local Autozone store instead of driving further to other Autozone store where purchased. Two different employees tried to say it can't be a bad battery - it must be my starter or alternator, and both told me I had to drive it back to the store that I purchased it from since it's not "in stock" at their store. I insisted the battery be tested and that it is an in stock item so they had to take it back. A nicer employee tested it and confirmed it was dead, and found the identical battery at a "hub" Autozone store. When I insisted I did not want to drive around any further, he ordered it to be delivered to this local store tomorrow morning. This time I'll have it tested before leaving the store.

 

best of luck getting your prius 12 volt squared away. Sorry to hear about difficulty with getting initial Autozone empolyee(s) to test, honor and replace their warranty product.

 

Having your own tester is empowering too, and/or motivates the store to dig out theirs.

 

I just installed a new Optima and also had to pop the small plastic cover off to manually open the hatch! Not the easiest install of a battery for sure but given my 2014 had the original 12v... Worth the effort!