replacing battery

[Chicobiker]

Hello.

Is a battery replacement a tricky task? It seems like it should be
fairly simple. Are there any peculiarities one should know in advance?

I have a 2003 Outback Sport. Over a year ago a mechanic told me my
battery failed a load test. It survived all winter, although last
winter wasn't particularly cold here. (not very often under -10C)

I did a rough test a month or two ago by leaving the headlights on and
checking the voltage every few minutes. The battery held 11.5v for 30
to 40 minutes before it started dropping.

The battery never seemed to like very cold mornings all along, so I was
considering replacing it anyway. Mostly I'm just curious if
disconnecting the battery for some period of time does anything to the
car's computer.

Thanks,
Chicobiker

 

[Carl 1 Lucky Texan]

Hello.

Is a battery replacement a tricky task? It seems like it should be
fairly simple. Are there any peculiarities one should know in advance?

I have a 2003 Outback Sport. Over a year ago a mechanic told me my
battery failed a load test. It survived all winter, although last
winter wasn't particularly cold here. (not very often under -10C)

I did a rough test a month or two ago by leaving the headlights on and
checking the voltage every few minutes. The battery held 11.5v for 30
to 40 minutes before it started dropping.

The battery never seemed to like very cold mornings all along, so I was
considering replacing it anyway. Mostly I'm just curious if
disconnecting the battery for some period of time does anything to the
car's computer.

Thanks,
Chicobiker

Tricky? Sometimes it's tricky getting the terminals off - easier with a
box end wrench. Sometimes requires twisting and GENTLE prying. Write
down your radio station presets. Car off, lights off, doors closed etc.
Put on safety glasses. Remove battery hold down clamp. Usually,
loosening and unhooking from the bottom is enough. Disconnect neg.
(black) terminal first (there could be some small sparks - don't worry)
and secure outta the way. Disconnect pos (red terminal, secure, remove
plastic shield if equipped, and carefully remove battery being careful
not squeeze the sides in much or spill fluid. Set aside. If you have a
small wire brush or a special batt. term. cleaner, brush the inside of
each terminal till mostly bright metal shows.Also, use a flashlight if
necessary and inspect the batt. tray for excessive corrosion, clogged
drain if equipped and familaiarize your self with the batt. hold down
clamp hook locations. Carefully place new battery in car in correct
position. Put plastic shield on battery, if equipped, do not leave out
as it may be desiged to direct cooling air/shield hot air, etc. Put pos
(red) cable on new batt. and secure. Place neg. (black) cable, watching
for small sparks, and secure. Smear dielectric grease over each
connection. Install hold down. Inspect battery for proper fluid level -
only top-up with demineralized/distilled water. Carefully inspect under
hood area for rags and tools. Clse hood, start car, program radio!

Carl

 

[Todd H.]

Carl gave you an excellent procedure. The only thing I'd add is that
when working on the first and last terminal (i.e. the negative
terminal, work with one hand behind your back.

And don't use a wrench long enough that you might touch it to the
positive terminal while working on the negative. That'd be bad.

Finally, I recently replaced a top terminal battery on someone's car
with one of those side terminal + top terminal batteries. The top
terminals were setbac from teh edge of the battery further than the
battery we were replacing, so we had to do some creative bending of
the factory terminals to flatten them to get them to fit.

And no, it's not that hard.

Oh, and if there's corrosion on the terminals, baking soda is nice to
throw on it. It's a base and will neutralize the acid that might be
around make it a little easier to clean.

In a pinch, if you don't have dielectric grease or electrical contact
grease, vaseline seems to work just fine.

 

[hippo]

Carl gave you an excellent procedure. The only thing I'd add is that
when working on the first and last terminal (i.e. the negative
terminal, work with one hand behind your back.

And don't use a wrench long enough that you might touch it to the
positive terminal while working on the negative. That'd be bad.

Todd H.

2001 Legacy Outback Wagon, 2.5L H-4
Chicago, Illinois USA

All good. I'd only only add - if you're wearing any rings, *please* take
them off before you statr working - just in case! Cheers

 

[David Coggins]

All good. I'd only only add - if you're wearing any rings, *please* take
them off before you statr working - just in case! Cheers

Yes!! I learned that lesson when I stuck my hand behind a car dashboard
while wearing a metal-banded watch. Result ... sparks and a burned wrist,
not to mention blown fuses.

Incidentally, there is a way to preserve the car radio memory using a nine
volt battery and a cigarette lighter plug, but probably not worth the effort
unless the radio has power off security protection. Cheers

 

[Chicobiker]

only top-up with demineralized/distilled water. Carefully inspect under
hood area for rags and tools.

That one made me laugh! Thanks.

And thanks for the tip on taking off the rings too.

Programming the radio is annoying, but no big deal.

Chicobiker

 

[Carl 1 Lucky Texan]

Carl 1 Lucky Texan wrote:




That one made me laugh! Thanks.

And thanks for the tip on taking off the rings too.

Programming the radio is annoying, but no big deal.

Chicobiker

Some radios may use flash memory or otherwise retain the settings. Also,
some security systems will freak out and beging flashing lights, etc.
Just hit the unlock on the remote several times, or maybe cycle the
ignition key on-off 3 times/whatever and it should be back to normal.
It seems complex all written out but should be a 45 minute job or so for
a first timer - probably under 30 miniutes you secong time. Don't rush -
do it right and you won't need to pay someone to re-do it.

Carl

 

[Clifford Heath]

Oh, and if there's corrosion on the terminals, baking soda is nice to
throw on it. It's a base and will neutralize the acid that might be
around make it a little easier to clean.

Actually, it's far more effective to slowly trickle a full jug of boiling
water over the terminals. Just loosen the top vents first, as the heat
causes slight venting and some batteries do that too slowly - you could
crack the casing.

 

[AS]

Excellent post Carl.

I have seen TSBs from some manufacturers that require technicians to use
a booster battery connected to the car, while replacing a vehicle's battery.

The reason given, is that in newer vehicles there are so many settings
that would get lost (radio, seat, steering wheel, pedal, mirror, climate
control, navigation, etc) that is not worth the aggravation. Not that
this is this the case with the 03 Sport, but...

I wash the battery, tray, frame, retention brackets, etc with a solution
of baking soda and water, until i see no further gassing of the
solution. This neutralizes the battery acid. I add baking soda to the
water until the water gets a lil "merky" with the soda. I use an old
tootbrush to clean the terminals and alike.

I have been using vaseline in battery terminals forever, with excellent
results. After all the post and terminals are clean and dry, I put the
vaseline on them before putting them together.

Besides, I try to set the terminals as high as possible on the posts, as
to keep battery acid away from them as much as possible. Some use the
felt disks covered with vaseline (grease) for the same purpose.

Good luck

 

[mulder]

Hello.

Is a battery replacement a tricky task? It seems like it should be
fairly simple. Are there any peculiarities one should know in advance?

I have a 2003 Outback Sport. Over a year ago a mechanic told me my
battery failed a load test. It survived all winter, although last
winter wasn't particularly cold here. (not very often under -10C)

I did a rough test a month or two ago by leaving the headlights on and
checking the voltage every few minutes. The battery held 11.5v for 30
to 40 minutes before it started dropping.

The battery never seemed to like very cold mornings all along, so I was
considering replacing it anyway. Mostly I'm just curious if
disconnecting the battery for some period of time does anything to the
car's computer.

Thanks,
Chicobiker

In addition to what others have said, I'll add some more info.
When the battery is disconnected, in addition to the radio presets
being lost the ECU loses its "learned" values for timing and idle. So,
when you next start and drive the car you may notice that the idle is
a bit erratic initially and performance and fuel mileage may be
different. These things will eventually return to normal as the car is
driven over a few days.
To prevent this, as well as retain the radio settings, you can use a
"memory saver" which can either be purchased commercially or made
yourself. This consists of just a 9V battery and a diode in series (to
prevent the car battery from backfeeding into the 9V battery which
would make it explode). These devices are usually sold with a lighter
plug but unfortunately that won't work with Subarus (and most other
foreign vehicles) because the socket is switched with the key. So,
what I do is use clipleads to connect the backup directly into the
fuse box to a constant 12V point (on my WRX there is a convenient stud
that is one of the terminals for a main fuse) and that works well.
The 9V battery is sufficient to retain the memory in the radio and
ECU, as long as you use a fresh 9V and make sure NOT to drain any
current while the car battery is disconnected. This means the key must
be out of the ignition, and the doors and trunk must remain closed.

 

[Mickey]

That one made me laugh! Thanks.

And thanks for the tip on taking off the rings too.

Programming the radio is annoying, but no big deal.

Chicobiker

You can avoid these no battery situations if you have an
extra 12 battery you can connect via jumper cables to the
cars battery cables. Doesn't have to be a large battery,
just enough power to hold systems up during the couple mins
the car battery is disconnected.

Mickey

 

[y_p_w]

You can avoid these no battery situations if you have an
extra 12 battery you can connect via jumper cables to the
cars battery cables. Doesn't have to be a large battery,
just enough power to hold systems up during the couple mins
the car battery is disconnected.

I've got an emergency jump starter. The only problem would
be where to rest it without risk that it falls over and takes
out some critical part.

 

[Dominic Richens]

Hello.

Is a battery replacement a tricky task? It seems like it should be
fairly simple. Are there any peculiarities one should know in advance?

Can't be too complicated. I did one in my driveway at night in -20C
weather.

 

[Carl 1 Lucky Texan]

In addition to what others have said, I'll add some more info.
When the battery is disconnected, in addition to the radio presets
being lost the ECU loses its "learned" values for timing and idle. So,
when you next start and drive the car you may notice that the idle is
a bit erratic initially and performance and fuel mileage may be
different. These things will eventually return to normal as the car is
driven over a few days.
To prevent this, as well as retain the radio settings, you can use a
"memory saver" which can either be purchased commercially or made
yourself. This consists of just a 9V battery and a diode in series (to
prevent the car battery from backfeeding into the 9V battery which
would make it explode). These devices are usually sold with a lighter
plug but unfortunately that won't work with Subarus (and most other
foreign vehicles) because the socket is switched with the key. So,
what I do is use clipleads to connect the backup directly into the
fuse box to a constant 12V point (on my WRX there is a convenient stud
that is one of the terminals for a main fuse) and that works well.
The 9V battery is sufficient to retain the memory in the radio and
ECU, as long as you use a fresh 9V and make sure NOT to drain any
current while the car battery is disconnected. This means the key must
be out of the ignition, and the doors and trunk must remain closed.

Yep, an older vehicle could drive oddly for a few drive cyclse as the
ECU adjusts for worn/lazy sensors.

good point

It seems it IS tricky changing a battery! look at the posts?

hah!

Carl

 

[Rick Courtright]

Programming the radio is annoying, but no big deal.

Hi,

Just be sure you know if there's a security code that needs to be input
to keep the radio working after the new battery goes in. Some of 'em die
when power's disconnected to discourage theft...

Rick