Battery Dying Way Too Soon

I think it is a question of whether enough movement happens around the car to trigger its look for fob response.

 

could be. mine sits in a very quiet garage. prime may also pull more juice for sks, idk.

 

I have never tried it myself, but according to the manual, you can enter "Battery-Saving" mode by simple taps on the key fob.

 

That does work. It's easy to test it and see that with the fob disabled the interior lights won't come on to welcome you when you walk up to the door. But I'm fairly sure it only affects that particular key to save the battery in the key. There is a separate programmable setting in the car, not in a menu but one of the things that the dealer and probably Carista can set, but I don't remember how configurable it is.

I usually disable my key if I'm going on vacation, for example. And I have my spare key disabled since it just sits at home. The lock and unlock buttons on the fob work as usual.

 

Yes, that wording in the manual does sound it is for saving battery in the key fob. For total Smart Key System shut off, it does seem to require dealer visit. OR Carista DIY. I am not sure if the Wireless remote control function is separate thing from SKS, but it can also be tuned off by a dealer.

3 is only dealer can change. 1 is with MID, 2 is with 11.6 display.

 

Yes but you can find a lot at half price.

 

the yellow highlighted area says fob battery and 12v battery. it sounds to me like it is automatic after a length of time without using it.

 

Right, the second bullet says after 14 days, and still not completely disabled. It says only drivers side door will open. and also wireless remote control function still works, meaning there still some drain in 12v battery with some sensors working.

 

and that's probably because sks drain isn't a big deal in the short run.

 

I was gone for a week at the end of last month. Car was not plugged in. Started just fine, I hadn't considered that it would not.

There is clearly something wrong with the OP's car or battery. When the 12V DOES eventually get old and die, replace it with a Yellowtop. They are deep cycle batteries which is the appropriate type for a car that doesn't have to crank a starter motor and then recharge.

 

Really, please tell us how you plan to make that big battery fit.


Rob43

 

Must be they come in multiple sizes. I've replaced 4 dying/dead OEM 12Vs in Gen II cars with Yellowtops, got them from eLearnAid. Cost a bit less than a new 12V from Toyota I think.

 

Sure, but a Prime is not a Gen 2 chassis.

There is no current Yellow Top battery that will fit into a Primes battery box, they are simply to long.


Rob43

 

Flooded and AGM lead acid batteries have different voltage requirements for charging. Car charging systems aren't selectable between those requirements. Putting an AGM into a car that had flooded for OEM could lead to shorter battery life.

Did those Optimas have vents?
Cabin installed batteries have vents because there is a risk of the battery giving off hydrogen sulfide, and it doesn't take much to kill everyone in the car.

 

But on the Prime, the 12V battery is under the hood, so this isn't an issue.

 

Many readers here still have a gen 3 or 2 Prius though, and maybe other models with a cabin installed battery.
My HHR did, and a woman and child died a few years ago when the under seat battery in their Porsche SUV released hydrogen sulfide.

 

Yes, they are vented. I don't know what eLearnAid is doing other than providing the battery for Gen II and Gen III Prii. Specifically sold for them with detailed instructions on replacing the battery including what and how to disassemble and reassemble things. IIRC the one I got for the 2004 had replacement connectors for the battery since the OEMs are smaller than "regular". But later versions of the battery that I got for the other Gen IIs did not require any modifications. Oh, and I first heard about eLearnAid here on PriusChat.

 

I've had a Noko for several years, finally used it a few months ago, worked great.

 

Other features on that device that make it handy - LED flashlight with strobe and SOS, and it can recharge a cellphone, which is nice for emergency use (i.e. car won't run).

 

An Optima battery, any color top, is a very expensive way to get a deep cycle battery if that's what one wants. The Optima batteries, and similar ones, are made to be "15 times more vibration-resistant". That's great for cars and trucks modified and used off road. It's a waste of money for a Prius. If a person wants a deep cycle battery, and if one will fit, a standard flooded lead acid deep cycle battery will cost a lot less than the vibration resistant ones. A sealed AGM battery that is not the spiral Optima type will cost less.

A deep cycle battery is designed to provide a low to moderate amount of electrical current for a long time. A standard auto starting battery is designed to provide a high current for a short time to power the engine's starter motor (which our Primes don't have). We do not know the internal design of the 12v battery that Toyota specifies for our cars.

Absorbed glass mat (AGM) lead acid batteries have fiberglass mat between the lead plates. The mats are saturated with dilute sulfuric acid (the standard lead acid battery electrolyte), then the battery is sealed. "AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive."
Absorbent Glass Mat (AGM) Battery Information - Battery University