12 volt battery life

I'm not an electrical expert but in my experience 24 months is within the range for auto batteries to lose functionionality these days.

If you can, do a voltage test before you fire up in the morning.

From what I've read on this forum you should have in excess of 11.7 volts. If not then likely your battery is dying or there is an electrical malfunction some where.

I'm sure someone with more knowledge will also advise.

 

If you can get a hold of a half-decent multimeter: check the voltage at the jumpstart terminal and a ground. A healthy battery will read 12.6 volts or higher. Anything around 12.5 or lower is iffy. You might be able to revive it with a charger.

 

Your battery should certainly last longer than 2yrs. The 12V battery in my 2006 lasted 5+yrs, with no problem whatsoever, until it suddenly died. A reading of 12.5V is within normal limits for a good battery. If you go for long periods (say-more than a week) without driving, I would manually turn off the headlights, and disable the smart key sensor (button under the dash, next to the tps button near the steering column)

 

My original 2005 battery is just fine.

 

My 2008 was just replaced last week. Took it to the dealer for the CEL light and they said it needed to be replaced. No problems starting recently; only had an issue in the dead of winter last year - had the windshield replaced/doors open for several hours in 20 degree weather and it died. No problems after jump start. No CEL light then either. The dealer hounded me for replacing it, but suspected they were just trying to sell a battery.

After it was replaced last week, 40 miles later the CEL light is back on. So I guess it wasn't the battery after all, but I'm still not so happy with the dealer and the diagnosis.

 

12.5v is fine. mine sits at about 12.4v and i have no problems and my gas mileage is normal. i have had this Optima for few years now.

 

a prius 12v battery should last 4 to 6 years (with smart key)

if the battery has to be jumped.. it has to be replaced... there really is no recovering these batteries from a dead state.. they just kinda keep staying dead (stops holding the charge it once did)

(just my opinion from experience.. and watching these forums) i always tell people to either have the car off... or in READY.... nothing else since these batteries are not very big.

 

I agree, it is in the chemistry of the lead acid battery. Running a lead acid battery low just nocks the life out of them.

 

Like all things, battery lifetime varies with quality. It will also depend not only upon age, but more importantly, the number of temperature ahd charge cycles the battery encounters.

Two years may be on the low end, but I bet it is within the normal range of failure rates for a typical driver, especially if you are in a warmer climate where batteries tend to have lower lifetime.

 

It,s actually a AGM battery for various safety reasons. The battery is only about 35 Amperes and the charging system is anemic, compared to other cars and trucks. I think Toyota design engineers had to make a sacrafice somewhere to maintain the HV at its highest charge and the 12V was it. The 12V cannot take having the radio and lights on for 5 hours in Aux mode. Always have it in ready, so the 12V at least maintains its charge.:rockon:

 

i kust replaced mine! 3,75 years old
did not drive a lot and car always at charger 12 volt when parked at home.
so i think that a bad periode... way to short

but now i have a new battery and a new smart trickle charger... lets see over 3-4 years!;-)

 

My Prius is a 2005. I had not ever checked the battery because it was not listed in the maintenance schedule. I changed the oil and air filter and next day all the lights on the display were blinking. I thought maybe some particulates got in the sensor under the air filter, cleaned it out and no change. I called the dealer who said have it towed in (it's 22 miles to the dealer). I asked if there was anything else I could try. He said disconnect the battery to see if it would clear the codes. I did, but afterwards all was blank. So it cost $220 for the tow, $186 for a new battery, and another $200 for diagnostics and labor. All that was wrong was that it had a dead battery. I have a charger at home. The take away is $600 is too much for a dead battery. It should have been listed in the maintenance schedule and I should have tried to charge it myself. It would have saved a lot of grief. The dealers said they should last 3 years, but to check it every year so you won't get a big surprise. That was my 2nd long distance tow for electronic problems. I have since joined AAA.

 

If you ever need a jump be sure the AAA tow service knows how to jump a Prius...better still learn how yourself and "supervise" . When you have the hood up locate the recommended jump points. Perhaps even mark them with colored tape...one is already red.

 

My service advisor early on told me to keep the key away from the car at least 15'. As all of the remote entry keys are, it is an addressable key and will drain the battery if left in the car or in close proximity to it. I am replacing my battery today and I have a 2007 1/2 prius that is 4 yrs and 7 months old. I thought it should go 5 years plus, but I think the cold weather has hastened its demise. Still, at the cost to replace this 12 volt battery, thought it should have a longer life.

 

how do u like the new wagon?

 

is the Optima battery + kit at $170 the best way to go for a replacement?

my 2007 has 103,00 and I figure it is time to replace it before any problems.

 

My unsupported position is that because the battery is in the passenger compartment, Toyota engineers leaned on the side of safety. Overcharging can cause Hydrogen gas or Sulfuric vapors to be released. That would be bad.