Replacement of 12 volt battery by owner

Yes, if you decide the settings are more important than your safety ( ) you will be working with energized terminals.

ALWAYS disconnect the -ve terminal first and connect it last. Even if you are keeping the settings with another power source. The reason is if you mess up and "ground" the +ve and the other lead is not connected you have no circuit to "weld with". Even if you are using another power source, the current from it will be limited by the leads and connection resistance. The battery you are installing won't have that limitation!

Again, DO NOT use a battery charger as a power source! The output is often not filtered very well, and probably not regulated re voltage very well. You -might- "get away" with it. You also -might- blow a several thousand dollar part or parts!

With a Prius, I even cringe when people connect a cheap battery charger -with- their battery still in the car.
You have something like seven computers, the inverter, and who knows what else in the car. They are always "connected" to the 12V system. Even when "off".

I have some battery checking to do this summer with Pearl. The system voltage was running at about 13.9 often this winter. I'm hoping it was because I left Pearl for a week at a time without running her, and the battery got a little lower than normal. I normally see 13.8 at all times except when off, of course. I have a fancy "pulse load battery tester" (http://www.ztsinc.com/index.html) that appears to be very good for evaluating batteries. So far it has told the truth, whether I wanted to hear it or not.

 

Thanks David & ETC(SS) - based on your good advice, it would be safer for me to not monkey around with hooking up a remote 12V source. The risk of major electrical damage is not worth trying to avoid the minor inconvenience of reseting the windows or a few radio presets.

 

NAPA sells an OPTIMA battery, #N9951YEL, for $139.00 that looks like it fits the 2010 Prius. It does require that you use the elearn adapter kit, which is $20.00 plus shipping. Has anyone used this battery? See below link for details.

https://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=NBRN9951YEL_0006503611&An=0

 

It appears to be the same Optima battery e-learnaid sells. Can't be absolutely sure though. Good price. I'll have to check locally. If they stock them locally it's a good buy. Or if they can get it in without extra shipping. Just remember, e-learnaid includes shipping in their price (except, of course, to Canada...sigh).

I purchased the adapter kit last year. To ensure my battery doesn't fail (it won't fail if I'm ready, right?).

 

Hi David,

I'm not familiar with the expression "-ve" terminal. Do you mean negative terminal?

 

I also purchased the e-learnaid adapter kit last month with the same idea of being ready, and maybe I won't need it for awhile. Mostly though, I want to be sure I don't get stuck having to buy an overpriced lower capacity Toyota battery from the dealer. I think the OPTIMA is a better quality battery and certainly a better value than the Toyota replacement.

 

Yes, electronics shorthand is -ve for negative. +ve is positive.

 

If I wanted to replace my 12-volt battery without losing the window, telephone, radio, and nav memories, could I start by putting the power switch in the ACC position -- thus turning on the DC/DC converter and delivering 12-volt power to the rest of the car from the 201-volt battery? Could I then disconnect the 12-volt battery, leaving the power switch as described, and connect the new 12-volt battery before turning off the power switch?

 

Look in the Gen II forum (search) - this has probably been answered many many times...

 

I've compared the 12 volt battery area of the 2010 Prius to my 2nd gen (06) and the 2010's looks a lot easier to replace. There seems to be a lot less in the way and less stuff to remove.

If the $289 (or whatever price) is a rip, get Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 10 instead. I did. Yes, there's some confusion and a mixed bag (for lack of a better word) on the pricing of an OEM replacement 12 volt.

I seriously doubt you'd need a new 12 volt on a 3rd gen at this point unless it's been abused (e.g. drained to depletion several times).

 

I understand that sentiment, but I have to disagree....only because my battery failed at 10K miles (7 months of service.)

Yeah...it's easy to say that you didn't abuse your car, and mine is a fleet vehicle. They get abused more than most.
Still.....other than about 200 miles, I'm the sole operator for mine. I'm pretty anal about flight ops with the company ride, since my beloved company only replaces automobiles when they reach lunar mileage, or voting age.
I don't like having to fill out paperwork or wait for the skid truck.
It's bad for my efficiency and productivity numbers.

Other than an old lawn mower whose battery failed at the 4 year point, this is the first vehicle that I've driven in 15 years that's had to be re-batteried, including my motorcycles.

Is this endemic for G3's?
Maybe, maybe not. One of my motorcycles (VRSCD, as I stated before) has a horrible reputation for devouring OEM batteries.

We’ll see.

 

Dealers have been known to "abuse" the 12v battery by not keeping them charged. It may be possible to bring a "slightly" abused battery with a desulfator (see: BatteryMINDer® Plus 12 Volt 1.33 Amp Charger-Maintainer-Conditioner (Desulfator) | All | Battery Chargers by BatteryMINDers.com ) as long as the abuse is fresh.

JeffD

 

I have same question. I'm new to site and did not see any reply. help. I got out of work yesterday and car was almost totally dead. got jump. today it's fine. but want to get battery and car checked. maybe something was left on. Wonder if it's life is 6 years and should do it anyway. Anyone have advise? thanks. Rob
05 prius (not plug in yet)

 

I am sure it is on PriusChat somewhere, but the version I bookmarked is about 3/4 down a page selling batteries delivered to you.

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