12V battery replacement as preventive maintenance?

[JimboK]

With 2.5 years on my car now, I'm starting to consider future inevitable service needs. The 12V battery will have to be replaced at some point, no doubt. I'd prefer not to wait until failure, but I'd rather not spend money prematurely. I've seen a smattering of reports from those who have, but I'd like to get a better sense of it (and consolidate the reports) from throughout the broader PC membership.

Who among the community has replaced their battery, or otherwise recommends it, as a preventive maintenance measure? If so, after what period of time?

[Rokeby]

JimboK,

I have been watching reports of 12V battery failure closely since I joined
in Jan '08.

Four years is the generally repeated, if not actually recommended, period
for considering replacement -- check voltage w/ ScanGuage on shutdown,
be sensative for weird happenings in the warning lights, random turning
on/off of wipers, etc

I'm sure the e-smart posters can add further clarity.

[Skwyre7]

3 years on mine and no problems. If it does go, I'll call you for a jump.

[andyprius]

Since the life of a battery is unknown (precisely) I have quit worrying about it, especially in a preventive service angle. I keep a small block battery in my trunk, charge off the cars system from time to time. When I have a no start problem I can easily switch to this block battery, then solve the larger problem of a new replacement battery. A couple of years ago, I ran the car only with the block battery and it worked great!

[Patrick Wong]

I replaced the battery in my 2001 when it was six years old, as a preventive measure. However I live in an area with moderate climate and drove the car daily, hence the battery was kept in a highly-charged state.

If you live in an area that gets snow in the winter, if you don't drive the car much and hence the battery has a chance to discharge, and if you would be highly inconvenienced when the battery fails unexpectedly, then I suggest you consider replacing the battery at 4 year intervals.

[hobbit]

I just did mine, replacing the original '04 [non smartkey] unit
with the yellowtop kit from elearnaid. The old one was still
mostly fine although its base light-load voltage seemed to be
a little shy of 12V and definitely dipped a bit during the process
of pre-booting the car, i.e. bringing ECUs online and running the
brake pump and all. Rather than watch its slow demise I decided
to get a new one, also giving more assurance of being able to
hold up the fan hack overnight on road-trips. I've still got
the old battery and will come up with something it can help
to power at home.
.
_H*

[efusco]

I'd say you're good for a minimum of 4 years...I changed mine at about that point after one incident of failure when using IgOn for about 15 min and getting a concensus that it was probably an early symptom of a dying battery.

[JimboK]

[Bump]

Thanks for all the responses. Anyone else?

[racerbob]

The 08 Silver Prius I selected was dead on the dealer lot. I had to stop the dumb salesman from attempting a jump start. He did not even know how to power up the vehicle. He held the power button down forever and waited for the ICE to start before releasing it on several other cars. I requested that he summon a Prius tech who jumped the vehicle and then put it on the charger for 3 hours. Because of the improper storage (car was on the lot for 3+ months), I chose to upgrade the battery to an Optima at 800 miles. I am using the original for a UPS in the house. The neg terminal was already starting to corrode (green fuzz) due to slight acid wicking around the post. On a brighter note, the tech who came to repair my car was a graduate from the tech college where I previously instructed (automotive technology). He was one of my better students in electrical and engine performance classes.

[Sheepdog]

I think most of us universally detest stupid car salesmen! The battery seems to be less stressed on the Pri than on most cars methinks. Else why would it be so small!