12v Battery problem? where is a good place to buy

I'm guessing you have the original battery ?? If so, I would plan on replacing it now. I would go with the Optima Yellow Top - Yes, the price may not be a pleasant surprise, but they are recommended for our vehicles. Do a search on this site to check. Good luck.

 

The Optima is described in this thread: http://priuschat.com/forums/prius-h...-12v-yellow-top-d51-battery-pencil-posts.html

It seems both this and the Toyota battery from the dealer are kind of expensive. Also, be aware that the Prius battery uses smaller terminals than most batteries, so you'd need some kind of adapter to make the connection to any battery other than Toyota's or Optima's.

 

The new "pencil post" Optima has the right size posts, no adapter kit is needed. A dealer should install a new Toyota battery for about $200.

 

There are not many options for replacements--it's not a common size/terminal type. The only ones I know of are the OEM, Optima and Odyssey.

The yellow top has a deep-cycle design that is able to survive many more discharge/charge cycles than the standard automotive battery that is OEM. The original batteries last 3-6 years. The yellow tops are expected to last 10+ years, possibly even 15+ years in the low-current, weather-protected Prius application.

You can also try checking the water level in the original battery. The battery in the '07 was low on water and was causing slow boot-ups and displaying the triangle warning light while booting.

I took out the battery and all of the 6 cells were low on water. Although the label says not to add water, just remove the label, pry out the clear plastic strip under it and carefully remove the 6, rubber cell caps. Then look into the holes with a flashlight and add distilled water to each cell until the whitish plates are submerged under about 1/4" of water. Then close everything back up. Put the battery on a slow, long smart-charge (I did a 1-amp charge for about 36 hours). This procedure has gotten my original battery to work well again.

A long charge is also helpful for these. The charging circuit on the Prius is not as high current as on conventional cars and if you don't regularly drive for hours at a time, the 12v battery usually doesn't get a very good charge, especially if it's been discharged. I make a habit of plugging in a smart charger under the hood for about 24 hours at least once a month.

Note--if you disconnect the 12v battery, you will lose radio memory pre-sets, reverse/seatbelt beeper disables and the driver's window auto up unless you attach another 12v source to the terminal inside the fuse box under the hood while the 12v battery is disconnected.

I'm going to maintain water levels and charging and try to use the original battery as long as I can, but if I do need to replace it, I'm going with the elearnaid kit with the group 51 Optima from here for $170. http://www.elearnaid.com/12vo1topraub.html

Eric

 

It is less likely to be flat after one complete discharge, it recovers better from you being forgetful.

You have three safe choices: (AGM battery with external venting)

'Custom' OEM battery from Toyoya. $140?

'Stock' Optima D51R Yellowtop with kit from elearnaid $170
Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 11

'Custom' Optima Yellowtop just for the Prius $200
Optima BatteriesOptima Batteries DS46B24R YellowTop Prius Auxiliary Battery

Both the last two will last longer, the 'stock' Yellowtop can be even cheaper next time you need a 12 volt battery (another 6 years?) as you won't need the kit then.

 

Hi- Last summer I replaced my orig batt with Yellow Top. However, very recently, Optima have a new "pencil top" version for Prius. Unless you really know what you are doing, you should stick with the eLearnaid supplier. If you go Amazon route, and you do not get the new pencil top post version (looks like you linked to the older version), you need adapter kit and instructions from eLearnaid. It is not as easy as a conventional car battery replacement. Some minor complexity for the DIYer. Took me 2-hrs but would be slightly easier with new pencil post version.

On a budget, the other thing you can try is calling Toyota dealers for an OEM battery. Some people have been quoted high cost (>~$200), but some have been quoted very low cost (~$100) for a new Toyota batt. So try your luck.

The Optima battery is probably more forgiving to a suboptimal use profile. But with lots of TLC, the orig Toyota 12V batt can last many years. BTW no water is added to these batts by the user.

 

The Amazon battery is the same Optima yellow top included in the kit from elearnaid, but it would require different cables to use (which are included in the elearnaid kit).

I think the only way to get the direct-fit Optima yellow top is to order it from from Optima:
Optima BatteriesOptima Batteries DS46B24R YellowTop Prius Auxiliary Battery

I highly recommend having a charger on hand, especially with your driving habits. I don't think a brand-new 12v battery would be able to stay charged sustainably with 5-minute drives and frequent starts.

I use a 2-amp black & decker smart charger that was on the shelf at Walmart--I think it was about $20.

Here are the instructions I wrote in another post for adding water:

"Yes, the label says never to add water, but as someone mentioned, it's more of an attempt to sell more batteries and to prevent liability issues. As long as you keep the battery upright and don't overfill it, it's pretty tough to get acid on yourself though.

Remove the intimidating warning label and place it upside down to reduce its intimidation factor (and keep the adhesive clean).

Then you'll see a transparent plastic strip covering the 6 cell fill caps. Carefully pry out the plastic strip with a flat-bladed screw driver or putty knife and set it aside. Then remove the small rubber caps but be careful not to lose them--they like to fly/roll.

The holes are pretty small, but with a flashlight, you should be able to see the whitish-colored plates inside. They were not submerged in the electrolyte when I had my battery out. Add enough distilled water to each cell to cover the plates inside (about 1/4" above the plates--don't fill the cells all the way!).

Then put the rubber cell plugs back on, press the clear strip back into place and replace the warning label. Put the battery on a slow, smart charger for a while if you can.

Adding water has really helped my original battery. I put it on a 1-amp smart charger for about 36 hours after I added water. Then the car sat for a week and then booted just fine the next time I drove it. No red-triangle light like I used to see. I think I can keep using the original battery a good while longer."

...and here's how to remove the battery from the car:

"Remove the trunk carpet mat, floor section, under-floor storage tray and the covers over the left and right portions of the trunk (you may be able to leave the left one in but I got it out of the way).

I like to unhook the negative battery terminal from the 12v battery first so I don't have to worry about grounding anything out with a wrench. If you don't want to lose the memory settings, you can attach a 12v power supply or battery to the jump-start terminal inside the fuse box under the hood to maintain power to the memory. Otherwise, a few things need to be reprogrammed later such as the radio presets, power window auto-up, and reverse/seat-belt beeper disables. It'll also lose the MPG average on the display.

The battery's in the rear, passenger-side corner of the trunk. The black box mounted just inside of it is the capacitor pack for emergency braking power in the event of an electrical failure. Move the capacitor pack out of the way by undoing the bolt on it's floor bracket and the small bolt on the top of the black box attached to the rear wall bracket. On that same wall bracket, there's a 12mm bolt just under the cargo anchor that you may have to loosen to get the capacitor pack out from under that wall bracket. I left the capacitor pack plugged in but just moved it aside.

Then just remove the section of ventilation ducting that's just forward of the 12v battery by removing the bolt holding it to the floor and the bolt holding it to the passenger-side wall (you may need to lift the interior paneling out of the way just a little to access the side wall bolt--be careful not to lose the bolt.

The red, plastic + terminal cover has three clips holding it to the black plastic connector assembly that can be carefully pried open with a flat-bladed screw driver. With the red cover removed, then you can remove the + battery terminal.

Then remove the battery hold down by removing the bolt attaching it to the floor and the nut on the threaded rod near the side wall (be careful not to lose the nut). I left the wiring harnesses connected and just moved the whole assembly aside.

Then pull off the small black vent tube fitting on the front side of the battery and you're good to go! "

 

The big benefit is that the optima is a deep cell battery, it can be discharged totally and will accept a full charge, bring it back to a "new" state, unlike the battery that was in the vehicle as it pulled off the dealers lot, it's a weak, easily depleted anchor, another benefit is, the optima is a gel battery, it won't emit deadly gasses inside the cabin of the vehicle, unlike the battery that came in the vehicle when new, which does, yes they(oem batteries) are vented into a tube which evacuates the fumes out of the cabin, hopefully.
If you buy your optima from an online parts store it'll be shipped, and most of them ship free, shop around.

 

That looks like the correct 'stock' battery, you would still need the elearnaid kit

Installation Kit for Optima battery in Prius

 

I can get the OEM Toyota battery for $136 delivered. That's easiest for me and they seem to last a long time in my application. I am still running the original in my 2005. But I think I need a new one, the at rest voltage is 12.5V now after sitting for 4hrs.

 

Since it is half electric, I think it is not safe to speculate the Optima is the same as the stock battery.
Luckily I didn't purchase the DieHard, otherwise it couldn't fit in there.

 

Why is that? I and many others here have personally installed Toyota Prius 12 Volt Auxiliary Battery with install kit for 2004 - 11 prior to http://priuschat.com/forums/prius-h...-12v-yellow-top-d51-battery-pencil-posts.html coming out, which others on Priuschat have installed.

The only fitment issue I'm aware of is if the Prius isn't equipped w/SKS (http://priuschat.com/forums/gen-ii-...es-optima-battery-really-fit.html#post1436415). Non-SKS Priuses came w/smaller 12 volt batteries.

 

That's actually not too bad. Why do you think it needs replacing?

 

Because the battery is pushing 7 years old but according to the following chart it is 90% charged at rest, which isn't too bad as you say. Maybe I'll keep it another year.

 

I just installed the new "pencil post" Optima Yellow Top in my non-SKS 2004 Prius. It was a bit longer than the OE battery (Which after 7.5 years and 213k miles rest at 12.55 volts and holds a charge!) and it still fit into the cubby with no problems.

JeffD

 

That chart is for a flooded lead-acid 12V battery. AGM at 100% charge is 12.9V, by the way.

 

Is that online? If so, can you point me there? My battery needs to be replaced.