Winter Battery/starting problem

Tylermelvin · 11-27-2015, 10:09 PM

Every winter I have to load my 78' 911 SC trunk w/ a battery charger so I don't get stranded. The cold weather kills my battery EVERY night, & when I leave it parked for longer than 3-5 hours depending on how cold it gets outside it dies on me. I have to charge it overnight and always try to park by an outlet unless I have space to push start, which I prefer not to do of course.

PLEASE HELP! So I can finally get rid of the charger from my trunk and just rely on it starting when I need it to.

timmy2 · timmy2's Garage

How old is the battery and have you had it tested?
What size is it? What are the rated CCA's
How cold is it wherever you are?

DRACO A5OG · DRACO A5OG's Garage

+1, have your battery tested.

wayner · 11-28-2015, 04:04 AM

I always reason that a battery is only good for 5 years.

You may get 7, you may get four, but at 5 I reason that as insurance, a new battery is cheaper than a tow truck. We are only talking a hundred bucks or so here, that 25 bucks a year (maybe 35 if you get an expensive one).

I've also run into situations over the years where a battery that load tests fine, still leaks down on its own when cold.

Also, batteries don't always die a slow death. Sometimes, especially if they have been drained down often, they build up crud on the plates and after one good bump, it can fall to the bottom and short out a cell and you are instantly stranded and in need of a battery.

An old battery can work fine one day and be forever dead the next.

If you don't want to buy one, at least eliminate the car electrical system as being the cause, by disconnecting the battery over night and seeing how it is the next morning when you reconnect it.

Limping along on an old battery is false economy in my opinion.

Tylermelvin · 11-28-2015, 04:25 AM

It's happened to at least two batteries over the years here in Utah where it gets down to 0-10 degrees during winter. It's not the battery, so I'll disconnect it today and see how that goes.

wayner · 11-28-2015, 05:39 AM

Mine are fine here in Canada where we get many -40 degree days (-40 is the same in F or C).

Even if I leave my vehicles for a week (although by then everything is so tight the starter struggles a bit)

You either have a draw (perhaps a short to ground somewhere) or not charging fully, or a weak connection to the battery (this could actually be a weak connection anywhere all the way back to the starter).

One trick is to try connecting the battery in the dark and see if it sparks when you touch the cable to the terminal. If so something is drawing current.

wwest · wwest's Garage

May be a faulty regulator.

Regulator has the ability to increase the charging voltage as a function of ambient temperature, the colder it gets the higher should be the charging voltage level.

Assuming you still have the external VR, easy (trial?) fix.

rick-l · 11-28-2015, 09:44 AM

What is the voltage at the battery running at 2000 RPM?

These regulators do not compensate for temperature.

tkmoore · tkmoore's Garage

+1 on the very real possibility of a faulty alternator or regulator. This slow loss of charge is very common with old alternator, which will prematurely kill the battery. I agree with testing battery, but also check charge of alternator at the battery with car off, with car running at idle, running at 2000 rpm, and 2000 rpm under load of lights, a/c etc. Good Luck, Tim

rick-l · 11-28-2015, 10:23 AM

you may have a problem all year and cold starting just accentuates it.

20W50 oil (like me)?

patz · 11:37 AM

I would suggest a deep cycle marine battery. My last yellow top optima lasted me 15 years. I permanently mount a pig tail on it that can be connected to my wall mounted Delran Battery Tender Plus. It has the best rep out there. It discreetly hangs out the front hood and I can hook up w/o opening the frunk.

Just don't leave it on the ground or forget to disconnect it. My asswipe roomie ran over it once, still works but looks like crap. Since it's not my daily driver, I leave a post it on the horn pad to disconnect it before starting.

Any battery that is less than 12.5 volts at rest, needs an EXTERNAL charge. Not from your rides alternator. If it can't show 12.5+, charge it. Have it tested and likely replaced if less.

I don't recommend those cheesy plug-in ciggy lighter chargers or volt meters. I have one mounted in the dash along with a head temp replacing the worthless clock.

I also have a AAA Premium road side service, 2-100 mile tows per year ..... cheap insurance. I also keep a GOOD quality set of jumper cables. NEVER let anyone else hook up cables. An oopsie from a dork that reverses the poles can fry your alternator and any up stream electronics. Expensive lesson and a lot of labor on YOUR part as dorkmeister isn't gonna help ya fix it.

wwest · wwest's Garage

Quote:

Originally Posted by rick-l

What is the voltage at the battery running at 2000 RPM?

These regulators do not compensate for temperature.

Mechanical VRs use a bi-metallic strip to adjust the charging voltage according to ambient temperatures.

Tylermelvin · 11-28-2015, 04:33 PM

I'm going to check the wiring to the starter. I'll post what happens next! Thanks for jogging my memory everyone.

Tremelune · 11-29-2015, 01:39 PM

I would put it on a Battery Tender Jr as a matter of course.

Something ain't right. It should go weeks of sitting without issue.

Tylermelvin · 12-07-2015, 12:57 PM

I checked the starter connections under the mid-rear passenger, the connection isn't loose, yet when I tighten or loosen the main nut the entire starter rotates.

Other than that I've have an updated stereo inserted over the past years, don't know how it did in winter before that.

Also, I do have it on a tender every night.

One last thing, my positive connection to the battery has a single red wire leading up into the dash, then under the carpet~ could be to an old sub that is no longer there, and then there are a major cluster of 3 red wires also connected to the positive...

Tylermelvin · 12-07-2015, 01:01 PM

Quote:

Originally Posted by rick-l

you may have a problem all year and cold starting just accentuates it.

20W50 oil (like me)?

Yeah, 20w50

darrin · 12-07-2015, 01:05 PM

you should first rule out a parasitic drain -- searching this term on pelicanparts brings up a few good threads on how to check, etc.

wwest · wwest's Garage

"entire starter rotates..."

"entire starter (electrical connection post[?]) rotates...."

Do you mean (common) a double-nutted electrical connection?

If so then you need to tighten the bottom/first nut to insure a good internal connection.

Tylermelvin · 12-07-2015, 01:05 PM

Quote:

Originally Posted by rick-l

you may have a problem all year and cold starting just accentuates it.

20W50 oil (like me)?

Quote:

Originally Posted by wayner

Mine are fine here in Canada where we get many -40 degree days (-40 is the same in F or C).

Even if I leave my vehicles for a week (although by then everything is so tight the starter struggles a bit)

You either have a draw (perhaps a short to ground somewhere) or not charging fully, or a weak connection to the battery (this could actually be a weak connection anywhere all the way back to the starter).

One trick is to try connecting the battery in the dark and see if it sparks when you touch the cable to the terminal. If so something is drawing current.

It actually did spark just now while connecting it to the terminal. What do I check from there? Everything I've checked that I know is tight. The starter does rotate when I attempt to tighten it though~sort of odd.

Tylermelvin · 12-07-2015, 01:08 PM

Quote:

Originally Posted by wwest

"entire starter rotates..."

"entire starter (electrical connection post[?]) rotates...."

Do you mean (common) a double-nutted electrical connection?

If so then you need to tighten the bottom/first nut to insure a good internal connection.

I wish I were able to see it better, I didn't see a nut visible on the bottom of the starter.