Spinman

My battery ('90) has a tendency to run down when the vehicle is not driven on a regular basis - which I attribute to parasitic drain.

While I have a quick battery disconnect installed under the hood, I would prefer not to use it except during the winter layover. I've been thinking about getting a battery tender and hooking it into the system via the lighter socket to ensure that the battery is maintained at full charge (assuming that the tender can compensate for the parasitic drain and then some). I havn't tested it yet - but I assume that the socket is always hot...

1) Would there be a problem by using the lighter socket method instead of clipping directly onto the battery terminals? Don't want to damage the alternator or internal wiring by pumping current into the system in this manner.

2) I want to run a test to ensure that I don't have a malfuction causing the drain. I undstand that I can attach an amp / volt meter and pull fuses one by one and see if there is a major change in current draw. Specifically - how would I go about testing this? What type of meter do I need to use? Where / how do I attach the meter?

Thanks -

Togo

i'm no expert, but there shouldn't be a problem - haven't you seen the jumper cables that go from cig lighter to cig lighter?
or how about the solar battery chargers that plug into the cig lighter?

just citing examples - again, i'm no expert!

oh, and a regular volt meter (digital ones can be had for under $10 if you know where to look) should do the trick

good luck

Dougs 90

As long as you are only in a trickle mode you should be fine, I have a solar panel for my 90 I run into the lighter socket to help keep the battery charged. I need to chase a few gremlins though. Have you determined your leakage and what is causing it? I would check that first.

Corvette Kid

The lighter is a direct battery link. As long as the capacity of the circuit is not exceeded, it'll be fine.

Dougs 90

disconnect the negative terminal of the battery
connect multimeter between the battery and disconnected terminal
measure as you pull 1fuse at a time

Mr Mojo

My Battery Tender Jr came with alligator clips and those circle clips.
All I do is run the wire through the gill and plug it in when I get home.

I don't even have to pop the hood.

jfb

It is safe to connect a battery tender into your cigarette lighter socket to keep your battery charged. GM says leakage current should not exceed 50 milliamps. My 87 draws 27 ma. Start the ammeter out on its highest scale because the courtesy lights will come on when you connect the meter between the negative cable and the negative battery post.
Also, disconnecting a battery for winter storage is not a good idea because even disconnected, lead acid batteries self discharge 1% each day and during discharge lead sulphate collects on the plates. Lead sulphate is a good insulator and a fully sulphated battery is a door stop. If you buy a battery tender, just connect it to the battery for winter storage. Your battery will be maintained fully charged and will experience a normal life. If you fully discharge the battery over winter by disconnecting it, you may ruin the battery by sulphating it. Also, each time you deep discharge a car battery you permanently lose some of its amp-hour capacity.

Corvette Kid

I've never understood where this 1% a day figure comes from. I was in the battery business years ago and never heard of it then, only here. Years ago, my (then) wife's car burned up the wiring under the hood and the dash. It was an old car and wasn't worth fixing. I put it out behind the garage I was then working at. A year later I needed a battery for something and went out and checked that one. It was still charged to 12.6v and provided service for quite some time after that.

jfb

Most car batteries are flooded cell batteries with lead-antimony alloy plates. These batteries have 8-40% self discharge per month, at the highest rate, that would be about 1% each day. Here is one source:
http://www.vonwentzel.net/Battery/00.Glossary/

Slalom4me

Out of curiosity, what kind of battery is it?

I've gone the 'solar panel for the summer', 'battery
disconnect and periodic charging for the winter' route
with my '89 for six+ years. For 'originality', I've
stuck with AC Delco batteries but I'm getting a bit
fed up with having to replace them about every two
years. I've had two now on warranty, but it is a minor
PITA to swap.

As another car got closer to being roadable late
last summer, I decided to get a Yellow Top Optima
for it. The Yellow is between their Red 'cranking'
battery and their 'Blue' neglect it and abuse it
battery. I replaced the Delco in the Vette last
June with new Delco on warranty because it
couldn't hold a charge despite being just a year
old (Spring '03). Already this year I notice that
the Delco doesn't peak as it should and I expect
it will fail in due course. The Yellow Optima
inadvertently got neglected but it is still performing
like a champ.

The message here isn't 'Optima good, Delco bad'.
I feel that the Delco design does not lend itself
to periods of inactivity and that it must sulphate
rapidly when out of use. In daily service, other
Delcos have worked well for me and this is through
our sub-minus 30ºF winters.

Instead the message is choose a battery suitable
for the application. When this Delco gets too weak,
it will be replaced with a deep-cycle unit that can
better tolerate the periodic inactivity that is part
of being in my Vette.

.

jfb

Deep cycle batteries should not be used for engine start service. Engine start batteries shouldn't be deep discharged, or even light discharge because their plates sulphate and that ends the batteries life. Get a battery tender and maintain a full charge on your car battery and it will experience a normal life.

Slalom4me

Gotta disagree with this generalization. Deep cycle
batteries are commonly used for starting in marine
and other applications. As I understand it, the issue
with starting is that a deep cycle battery is unable
to release energy as readily, making it less effective
as a 'starting' battery.

As far as the suitability of a Yellow Top Optima for
periodic starting usage, here's what they say about it
themselves:

. "The YellowTop handles many discharges as well as
. re-charges without losing significant capacity.
. OPTIMA is also ideal for seasonal use because of its
. very low self-discharge rate. That means you can
. store your seasonal vehicles all winter without
. regular charging and still spring out of the starting
. block when winter is over."

No disagreement here. This is a cheaper solution
than a Yellow Top, too. It is just that I was having
trouble even using/charging enough during summer
months, let alone the winter. Plus, when I store the
car, power is not always readily available. This is
why I'll be changing when the Delco expires - I just
wish the Yellow Top wasn't so hard on the eyes.

.

R23HTC

Since I already had an amp in the car wired to the battery I just got another post extender and put in on the negative side. I took the 2 round leads from my Battery Tender and enlarged them to fit the posts. The other end plugs into the tender and has a weather proof cap when it's not in use. I just tuck it away in the metal support that runs on the fender and you can barely tell it's there. If the car is going to be down, you can pop the hood, plug it in, lay the wire over the wheel well and then close the hood. It worked great all winter.

Chris_G

whatever works

jfb

Partial quote:

Gotta disagree with this generalization. Deep cycle
batteries are commonly used for starting in marine
and other applications.
---------------------------------------------------------------

Marine batteries claiming cranking and deep discharge service are poor deep discharge batteries and if used in deep discharge will have a short life. True deep discharge batteries not recommended for cranking are damaged if used for cranking. Check google for verification, I did.

Mr Mojo

AC Delco batteries suck because they suck.

I've seen too many cars(mine included) where the terminals actually fell off the battery.

R23HTC

Exactly what happened to the one on my wife's '01 Malibu!