Sudden 12V battery failure

This is true with a regular battery. However an AGM battery is not supposed to have free liquid electrolyte within. The mats are supposed to hold the electrolyte.
http://en.wikipedia.org/wiki/Agm_battery

I don't understand why bredekamp's battery showed some cells with liquid while the others were dry. Maybe this shows that the mats were starting to break down?

 

Perhaps the Prius for South Africa has a different battery.

In one of Hobbit's threads on 12v battery he says this about the Nippon Denso GS battery ,"as I tilted this thing I clearly saw liquid levels rising and falling against the cell walls! It's flooded,regardless of what substance is between the plates."

 

Hobbit has the base model 2004 with the smaller GS battery that has a translucent white case. That battery is similar to the Classic battery, except for opposite terminal polarity. Hobbit's post provides another example of a GS battery with visible liquid.

My point is simply that some but not all GS batteries have this visible liquid. The batteries appear identical on the outside. Who knows why this happens...

 

The entries in this thread seem to say a dead 12 volt battery is
a> a battery problem
b> requires almost daily driving

This has happened to me twice in the 21 months I have owned the prius. Each time the dealer pays for having the car towed about 50 miles to the dealership and rplacing the 12 volt battery. I am not leaving the lights on or the door open or any other obvious battery drains. The dealer says drive it more often. A car, even a Prius, should not dictate my life. I think there must be a reason for this problem. Perhaps a failure of one of the modules of the computer program? I can live with a battery lasting only 2 years but I do not want to carry around a container of caustic chemicals. Has anyone found a explanation for this problem? And maybe a fix?

 

posted it before
i have a small solar panel now to keep the battery not discharging or les discharging during the day when its standing stil
i place it inside the car but you can also put it in your garage behind a window and connect it to the battery

the prius aux battery is simply small and the charging current is low to because off the small battery no mare then 4 amps.

 

You top up a battery with pure water not caustic chemicals and acid is the opposite to caustic.

Glass mat or no glass mat, I like to see liquid above the plates in my battery.

 

In principle, you should be able to install an AGM battery on its side or even upside down - and not worry about liquid acid coming out of the vent. I would not characterize that as "flooded".

 

That's a great price. In the US the dealer price is typically US$160 for the replacement GS battery made in Japan.

I'm interested to hear whether the new battery is also a GS; if so does it make sloshing sounds when you shake it.

 

Did your genuine replacement battery come with any specifications? It might help find an alternative for those of us in countries where Toyota want us to pay $457 (Australian)or about US$435 for a replacement!

 

Check with your local BatteryWorld or Auto parts shop, I think you will find they have them in stock. If not I am willing to bet they have a listing and can get them in.
I wonder if Aussie spec cars have a different 12v battery to US spec cars?

 

Hi Pat,

My understanding is that there are only two battery capacities: the 28AH battery for Prius without Smart Entry/Smart Start; and a longer, low 30's AH battery for Prius with that feature.

The GS batteries are made in Japan. If your GS battery's case has translucent white plastic on its sides then it is the smaller version. If the battery has an all-black case then it is the larger version.

If your battery is not GS then you may have a different spec.

 

It's quite common for car batteries to "fail" due to loss of water. If you top them up they are good for quite a while longer, as long as no cell got completely dry and sulphated. I had to add water to the anti-Prius' battery every year to keep it going. It lasted the full 8 years I had that vehicle and was still healthy when I traded it in for the Prius.
I suspect your battery was fine once you added the water. BTW, while I won't dispute deionized distilled water is best, I haven't seen any negative effects from adding "regular" water. And I've always kept my batteries for their full life of 7 years or so in an extreme climate (-40C winters).

 

Went thru Hobbits procedure yesterday, my little gel, block battery rated at 7AH worked fine as a back-up to prevent memory loss. I installed a leadacid Panasonic from my daughter-in-laws RAV4. It still showed the blue charge check and read about 12.45 Volts, I drilled a hole on the side, near the top for the vent and filed down the pos terminal to fit the Japanese connector. On the neg terminal I just used an adapter terminal with a wingnut and a jumper cable. System worked fine I took it for a 3 mile ride and the battery charged a bit to 12.6 volts. So now I have a spare when mine fails and I have the Emergency 7AH Gel if I'm away from home. This battery I took for a 6 mile ride and it and the car worked fine. Incidentally, the GS bat on my 05 has yellow stickers on it, peel those off and underneath is a clear plastic that looks easily pryable for adding H20 if necessary. Should you use hobbits procedure, which is excellent! and you cancel the SKS and open trunk lid light. Don't even think of prying that trunk lock back to its unlock position. I almost went that route! Simply reinitiate the SKS and then reach up and hit the unlock button on the trunk lid. I really don't think that the battery replacement is that critical. The criteria being: Does it provide something over 12VDC plus 1-2 volts, Is the current carrying capacity sufficient to cover the usual prius loads AND most importantly Is the replacement battery staying charged? This can be checked with the MFD Diagnostic procedure. The Honda Bat fits nicely, its currently carrying capability is more that sufficient and since the boot-up procedure requires minimal force, 12VDC and probably a current draw in the ma range, the battery life may be infinity. ( unless, I move to either Fairbanks or the Sahara Desert. No doubt, there will be some Techies out there that will opppose my Laizez-Faire attitude. But, that's OK.:cheer2: Unfotunately I paid nothing for the Panasonic, I feel guilty about that.................................................................

 

Anyone know how to open the rear hatch when the 12v battery is dead? I couldn't get to my jumper cables that were stored in the hatch area and had to borrow another set to start the car and release the rear hatch.

 

I had to take a trip 35 days after I bought my Prius, I was gone 17 days. I tried to get in my car at the airport parking lot and could not get my car open, had to use the key, popped the hood and the airport help vehicle gave me a jump start. I now have two "yellow" top batteries in it.