12 Volt Car "Jump-Starter" or??

[kb4ns]

Alright, so I'm thinking about buying one of the 12v "jump starters". Every time my squad car ('09 Crown Vic) sits for more than 48 hours, the battery goes dead. I've had the battery & alternator checked by the guys at our city shop and everything is ok. I know something is pulling on the battery, but I cannot for the life of me figure out what. The radio, the camera system, the lighting/siren system, everything that I plug into a cig outlet - all off or unplugged. It's getting rather inconvenient to keep rearranging vehicles at my house to jump off my squad car after my days off.

The jump starter units run about $50 at Harbor freight. What other ideas (cheaper ideas) do you guys have? I would just undo a battery cable when I park it, but that's a pain in the rear. I'm somewhat vehicle savvy and can only get away with doing so much to the city's car without getting into too much trouble. What ideas y'all got??

[titan14]

My opinion.....take it to the Ford dealer and make them fix it....under warranty i might add....

Or tell the city garage manager to get someone hired that can fix it....

P.S. I am not even close to being a mechanic, but, there HAS to be a "ground" loose, somewhere....

[nightrunner]

I would suggest getting a higher quality unit than harbor freight, I had a unit from walmart and it messed up first time I used it. found a good one at tractor supply but never got it. dont have room to carry it in my camaro now like i did in my truck. you will want a 600amp+ jump starter.

some have air compressors for flat tires made into the unit also, and some include AC/DC converters

[kb4ns]

Titan-

Well, they put their fancy machines on it that say the car itself (battery, etc) is 100% working correctly, which I believe since the car starts just fine if I drove it the day before. During my 6 day work week, it starts fine every morning after the first, so it's gotta be something added onto the vehicle. The dealership isn't gonna try to figure that one out as it's not their issue. :-\

[titan14]

True...I'd still make 'em look at it...maybe someone that deals in Fords all the time, might see something awry. Its worth a shot.

[kb4ns]

I would suggest getting a higher quality unit than harbor freight, I had a unit from walmart and it messed up first time I used it. found a good one at tractor supply but never got it. dont have room to carry it in my camaro now like i did in my truck. you will want a 600amp+ jump starter.

The Harbor Freight unit is advertised as "400 amp boost rate / 900 amp peak". IIRC, they have a pretty decent warranty on their stuff, so if it sucks, I ought to be able to return it.

Here's a link to the product I'm looking at- 12 Volt Jump-Start and Power Supply

EDIT: I just looked. It appears to have a 30 day warranty. That should be plenty of time to see if it works, but with my luck, it would crap out on day 31...

[Guest jackdm3]

Titan: No way they're gonna troubleshoot add-ons under a factory warrantee.

kb: How is the department/city not helping you on this? Or do you have personal goodies running that don't concern them.

[56FordGuy]

Do you have a GPS tracking unit on your car? A lot of them run 100% of the time, whether the vehicle is running or not. As a result, they can kill the battery. Granted two days seems a little short for it to happen, but y'alls system may draw more than the ones my company uses do.

[Guest Jamie]

Alright, so I'm thinking about buying one of the 12v "jump starters". Every time my squad car ('09 Crown Vic) sits for more than 48 hours, the battery goes dead. I've had the battery & alternator checked by the guys at our city shop and everything is ok. I know something is pulling on the battery, but I cannot for the life of me figure out what. The radio, the camera system, the lighting/siren system, everything that I plug into a cig outlet - all off or unplugged. It's getting rather inconvenient to keep rearranging vehicles at my house to jump off my squad car after my days off.

The jump starter units run about $50 at Harbor freight. What other ideas (cheaper ideas) do you guys have? I would just undo a battery cable when I park it, but that's a pain in the rear. I'm somewhat vehicle savvy and can only get away with doing so much to the city's car without getting into too much trouble. What ideas y'all got??

This may sound stupid, but check the trunk light and the light under the hood, if it has one.

I know somebody who went 'round and around with the dealership over the very problem you're having... and in the end, it was the trunk light that was pulling the battery down. Seems the switch went south, and the light was staying on constantly.

May not be the problem with your patrol car, but it's worth checking.

J.

[Trekbike]

I had a similar battery drain with my Volvo 850. It had a lighted glovebox and the lid wasn't pushing in the activation button enough to cut it off when closed. The problem went away after correcting. It's worth a check if has a light. It's obviously got a drain somewhere.

Visor light maybe??? Have you checked out the car at night?

Edited August 3, 2010 by Trekbike

[Guest bkelm18]

We use this jump starter at work:

PowerStation Jumpstarter, Model# PS1118 | Portable Jump Starters | Northern Tool + Equipment

We've had it for about a year and we jump off probably almost a dozen vehicles a week with it. It's a real time saver. We even left it out in the rain accidentally once. We let it dry out and it kept on going.

[oldogy]

Easier than a battery jumper system would be a disconnect switch on the battery. Cheaper, too. JMO. Now on to the subject of battery drain. A year or so ago I had conversation with a Ford electrical tec. and me having some serious electronic experience and training, the conversation got fairly deep into new vehicle electronics. He said one of the problems with the newer vehicles was that they have a main computer and several secondary or slave computers. The problem comes in trying to diagnose which one of the secondary computers is not shutting down and draining the battery. We discussed the exact symptoms you are experiencing. He indicated this was not all that uncommon problem. FWIW.

oldogy

[-boatman-]

Maybe you should call the city for a jump every time it does not start. Then maybe they would get tired of coming out and find the problem.

First I would do like others have said and check for lights staying on. Sometimes it is something simple like that.

[MCSCOTT]

Most any jumper box that I've ever used worked just as good as any for simply jumping off the vehicle. There's also the idea of the disconnect, either in the form of those breaker type switches or the quick disconnect that has the knob on the battery cable. For me these would only be temporary fixes though, because at some point someone needs to really dig in there and figure out what's draining the battery. If the garage installed the lights, radios, etc, then they should be the ones to have to dig to find the bad connection. If you installed any of it, then take one of your off days and start tracking down all of your wiring until you find the issue. If nothing can be found there, then I would go back to the dealership and let them know that the issue seems to be on their end.

[G27]

I bet you have an additional radiator fan on that car - patrol cars are built to idle in heat - could be a bad thermostat or similar causing the fan to run even after the car has reached nominal temp.

[Guest Lester Weevils]

Desirable to get the root problem fixed of course, but a battery jumper is really handy to keep in the back of the car or truck. Good for helping folks, and an argument could be made it could be an essential bug-out item if bugging out with a vehicle.

I wore out a cheap jumpstarter after maybe 5 years. It used a wall-wart transformer for charging. Worked OK till it died.

Then got wife a nicer Husky Home Depot starter with 120 volt inverter, air pump, emergency LED light, and of course jump-start capability. Dunno if all modern jumpstarters have an on-off switch, but it is a great feature. You can connect to the auto battery with the switch turned off, then turn it on, start the engine, then turn off the jumpstarter to remove the cables. It doesn't throw sparks when making connections, and isn't as risky if one were to accidentally drop a cable into the engine compartment, possibly accidentally short the starter against the frame.

That Husky model also charges by connecting an ordinary grounded extension cord to a male 120 volt fixture on the jumpstarter. Which is much more convenient than a wallwart. No risk losing the wallwart. As long as you can find an extension cable yer good to go for charging. Also has a 'quasi-smart' charging circuit that shuts off when charged, and a digital DC voltmeter.

In a pinch you could run small power tools or charge/run cellphone or laptop off the inverter, and I routinely use the gadget to top off tire pressure. The pump takes a few minutes to move a car tire pressure more than a few pounds, and about 30 secs to a minute to move it a few pounds. But it is so convenient I haven't used gas station air since getting the jumpstarters. One time I fully pumped up a neighbor's completely flat Explorer tire, pretty big tire with a slow leak. Took about 5 minutes to completely inflate the tire, but at least it got the job done.

Liked hers so much I got an identical for my van.

Home Depot doesn't sell that model of husky anymore (according to their web site) but this Black'n'Decker looks roughly equivalent. Dunno if it matches feature-for-feature, but looks close.

400 AC/DC Portable Power Station/Jump-Starter/Compressor - VEC026BD at The Home Depot

[vontar]

The last time my Ford Ranger was having that problem even though the alternator was charging good, it was a bad alternator.

It has a short in the alternator that was not detectable by the testing, as the testing only showed whether or not it was charging but did determine if there was a short in it.

I replaced the alternator and the problem has not come back.

Advance auto test said my alternator was good, but my short was in it.

In the meantime, if you are going to park it for 48 hours, disconnect a battery cable. See if it goes dead with a cable off.

What I suspect caused my problem, about 2 months before I had a water hose blow and it blew water/anti freeze everywhere under the hood right beside the alternator and I am pretty sure it got in it.

[strickj]

The only reliable way to test an alt or batt is to take them out of the car. The roll out tester that parts stores use can only tell you if your battery is charged and your alternator is working. It can not tell you whether or not your battery is holding a charge or if your voltage regulator is working properly.

seeing how your battery goes dead only after it sits for a couple days and you're looking at $$, I would get a cheap trickle charger instead of the jump starter.

[vontar]

I found my after talking to a former mechanic.

after I left my battery unhooked and it stayed up. ruled out the battery, re connnected it,

unhooked the alternator and found the battery also stayed up. with the alternator connected the battery would go dead..

Maybe I got lucky

[Guest DRB]

Could be the alternator... Mine (98 Grand Marquis) was the glove box light staying on.

I checked out a noise late one night and noticed that the car looked *weird*. It was that light. I NEVER would have found it otherwise.

Like someone said earlier - Check it out in the dark. It only takes a minute.

[kb4ns]

kb: How is the department/city not helping you on this? Or do you have personal goodies running that don't concern them.

There are some personal goodies (Sirius Radio & GPS), but that isn't my issue as I unplug them daily. They'll let me take it to the dealership, shop, or Comserv (radio shop) as often as I need to, but nobody can figure it out.

Do you have a GPS tracking unit on your car? A lot of them run 100% of the time, whether the vehicle is running or not. As a result, they can kill the battery. Granted two days seems a little short for it to happen, but y'alls system may draw more than the ones my company uses do.

The only GPS (besides my TomTom that I unplug) is built into the dash camera. I've tried pulling the power completely to the entire unit. No luck.

This may sound stupid, but check the trunk light and the light under the hood, if it has one.

I actually haven't checked the trunk light. The battery is dead at the moment since I've been off for this eye surgery. As soon as I get it restarted before returning to work, I'll check that.

I had a similar battery drain with my Volvo 850. It had a lighted glovebox and the lid wasn't pushing in the activation button enough to cut it off when closed. The problem went away after correcting. It's worth a check if has a light. It's obviously got a drain somewhere.

Visor light maybe??? Have you checked out the car at night?

It's nothing in the interior. The car sits basically right in front of my kitchen window and I glance out at it everytime I'm in the kitchen at night.

Maybe you should call the city for a jump every time it does not start. Then maybe they would get tired of coming out and find the problem.

LOL. That'd be shooting myself in the foot. They'd take my take-home car away.

[kb4ns]

Easier than a battery jumper system would be a disconnect switch on the battery.

There's also the idea of the disconnect, either in the form of those breaker type switches or the quick disconnect that has the knob on the battery cable.

I might have to look into this idea. Any suggestions on the easiest way to do a cut-off switch?

I bet you have an additional radiator fan on that car - patrol cars are built to idle in heat - could be a bad thermostat or similar causing the fan to run even after the car has reached nominal temp.

Possible. I've never heard anything, but those fans are pretty quiet. Unless there's something making it run constantly over the course of two days, I would think it'd be dead every morning when I'm in my work week.

I would get a cheap trickle charger instead of the jump starter.

I've thought about getting one of those battery tender style maintainers that allow you to leave the leads on the battery & run a plug to the grille for easy connecting/disconnecting, but the wife would probably take issue with it. I'd have to either run an eaxtension cord out of the front door or from around the back of the house. :-\

Lester & bkelm, I appreciate the suggestions on the jump-start units. I might try the cut-off switch thing first. I agree that a good jump start unit would have many uses besides my current problem, but I need to not spend the money right now if I can help it.

[hardknox00001]

I'm thumbnailing, so some thought is in process as typing is occurring......................

Something like this is simple in that you intall the switch inline with positive battery cable. I have seen switches like this in local parts houses, these are sort of common. I found this link by googling "12v master switch".

Mustang Master Disconnect Relocation Battery Switch at AmericanMuscle.com - Free Shipping!

It has two studs. Connect battery to one side, vehicle to other, that's it. You would have to modify the positive battery cable somewhere convienient by cutting it in half and soldering on some bigger ring terminals and screwing them down on the studs. Probably would want to mount the switch in a plastic electrical box for insulatory considerations on the switches exposed studs, which would allow for screwing/strapping the whole mess down to something possibly. Too bad your over there, if you were over here I could whip this up in less than an hour if I had all the parts in front of me............

Edit - If you decide to go with the switch idea, just make sure that the amp rating of the switch is over what the vehicle will pull (starting and when all lights, sirens, a/c, t.v., coffee maker, donut warmer, etc is running) or the switch will melt.......................

Edited August 3, 2010 by hardknox00001

[kb4ns]

Where would I mount a switch like that? Under dash or...?

[kb4ns]

An even easier (and less permanent) option is the battery disconnect knob that MCSCOTT suggested. I was looking at this one - BATTERY DISCONNECT SWITCHES - JCWhitney

It has a 15 amp bypass to allow the clock to keep settings, etc. For my issue, it seems like this would defeat the purpose. I reckon I could install the disconnect knob without the bypass. It's rated at 125 amps. I figured it all up and all the aftermarket doodads running at once should be about 75 amps at the most (yeah, there's a lot of crap on the car). That'd leave about 50 amps for the vehicle itself. What kind of amperage does the average car without aftermarket crap use?

EDIT: A deeper search into that product suggests that it is rated for 125A continuous, 500A peak. I think this would work. Any naysayers? Please feel free to jump in and keep me from screwing something up!

Edited August 3, 2010 by kb4ns