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Andrew B.
02-23-2009, 04:51 PM
Because my health is bad, I rarely drive my car. But the result is my battery goes dead, even though I have a good quality battery. And there is no way for me to recharge it where my car sits.

What is the minimum I would have to drive my car to keep it charged? Or, can I charge the battery by idling in place? Any other suggestions?

dom
02-23-2009, 05:05 PM
Hello Andrew B,

here are a few things you can do. Ordered from simple to more difficult.



Just start it up every two weeks or so and let it idle for around 20 minutes.
Put a battery tender on it (will have to have a wall socket nearby)
Install a switch inline to one of your battery cables (cutting power off completely).

Personally, I would just start the car up every couple weeks and let it idle.

Eric
02-23-2009, 05:36 PM
Because my health is bad, I rarely drive my car. But the result is my battery goes dead, even though I have a good quality battery. And there is no way for me to recharge it where my car sits.

What is the minimum I would have to drive my car to keep it charged? Or, can I charge the battery by idling in place? Any other suggestions?

I recommend an automatic trickle charger. This is a very simple/foolproof device that costs about $40. It has a pair of cables that you hook up to the battery (one for the positive terminal, the other for negative/ground). You plug it into any household 110V outlet and it will automatically maintain your battery at full charge. It will turn itself on and off automatically.

I would recommend this over idling the car because (first) starting the car draws a lot of charge - which drains the battery, while just idling (at low engine RPM) may not provide sufficient re-charging via the alternator. And even if did, it's no good for the vehicle to just start it and leave it idling. It should be driven for at least 15-20 minutes each time it's started. (Otherwise, the engine may not reach full operating temp., which could result in crankcase condensation (water and gas), which dilutes/contaminates the oil - etc.

Also, unless you drive the car at least once a week or so for 15-20 minutes, it's likely the battery will still be discharged more than it's charged - which brings us back to the trickle charger.

Hope this is helpful....

DonTom
02-23-2009, 10:45 PM
Because my health is bad, I rarely drive my car. But the result is my battery goes dead, even though I have a good quality battery. And there is no way for me to recharge it where my car sits.

What is the minimum I would have to drive my car to keep it charged? Or, can I charge the battery by idling in place? Any other suggestions?

You did not mention what type of vehicle. Jeep / Chrysler / Dodge often have a high IOD (Ignition Off Draw). However, all these vehicles have an IOD fuse under the hood that can be easily removed to stop battery drain. It's usually easier to remove the fuse than to disconnect the negative battery lead. This fuse should be removed if the vehicle is not going to be started for more than ten days. However, you will lose your radio memory and in some vehicles, the anti-thieft kicks in and you need to know the code to get your radio going again. On E-Bay, they sell the information for you to get your own code from the radio itself, for 99 cents. This is all you need for about 99% of radios with the so-called "theft deterrent". Your vehicle alarm will still function with the IOD fuse removed (in most vehicles). In most vehicles, the interior door lights will not function when the IOD fuse is removed. The light not lighting when you open the door works well to remind you to put the IOD fuse back in before driving. In some vehicles, the electronic door locks and turn signals will not work while the IOD fuse removed.

If your battery is very discharged, such as just barely will start the engine, it might take as much as a five hour drive to charge it to a FULL charge. However, just a few minutes at idle can help quite a bit.

Or, if you don't want to bother with the IOD fuse, if there's sunlight where the car is parked a small cheap solar charger (http://www.jcwhitney.com/autoparts/Product/Pr-p_Product.CATENTRY_ID:2012890/c-10101/Nty-1/p-2012890/Ntx-mode+matchallpartial/N-10101/tf-Browse/s-10101/Ntk-AllTextSearchGroup?Ntt=Solar+chargfer)should help. The type that plug into a cigarette lighter as shown here should be all that you need.


-Don- San Francisco, CA

Andrew B.
02-24-2009, 12:50 AM
Thanks for posting so quickly! I should have mentioned before that the car is a 1994 Mazda 626 LX-V6 that I keep parked in a lower parking level where there is no sun and no electric outlet. Also, it has a car alarm, which I'm sure drains some of the power. So I guess my solution would be to drive it 15-20 minutes per week, or have someone else drive it.

OTOH, maybe I could just just sit in it with the window opened and run it at RPMs that approximate driving. And make sure it warms up. Or maybe just do this sometimes. It is probably better to actually drive it some of the time.

Eric
02-24-2009, 06:47 AM
"So I guess my solution would be to drive it 15-20 minutes per week, or have someone else drive it."

This is the best option, in my opinion.

"OTOH, maybe I could just just sit in it with the window opened and run it at RPMs that approximate driving. And make sure it warms up. Or maybe just do this sometimes. It is probably better to actually drive it some of the time."

Don't do this - please!

The lack of airflow could cause overheating and other problems; remember - you're still not driving. Yes, you'll work the charging system - but the transmission is in neutral and nothing's moving. Just revving the engine is not recommended!

DonTom
02-24-2009, 09:30 AM
" OTOH, maybe I could just just sit in it with the window opened and run it at RPMs that approximate driving. "

Alternators charge as well at idle. In some cases, a fast idle is needed, but not more.


-Don-

Eric
02-24-2009, 09:40 AM
" OTOH, maybe I could just just sit in it with the window opened and run it at RPMs that approximate driving. "

Alternators charge as well at idle. In some cases, a fast idle is needed, but not more.


-Don-


Yes, but if the battery is perpetually discharged/low charge and you use the alternator to recharge it (instead of a trickle charger) won't this cause excessive/premature wear of the alternator? (And these days, those suckers are expensive - $400 and more, I gather, being common.)

DonTom
02-24-2009, 05:43 PM
Yes, but if the battery is perpetually discharged/low charge and you use the alternator to recharge it (instead of a trickle charger) won't this cause excessive/premature wear of the alternator? (And these days, those suckers are expensive - $400 and more, I gather, being common.)

I am all for using a solar or battery maintainer if possible, but it's not in his case. He should either remove the IOD fuse or disconnect the battery. It's difficult to get a full charge from simply letting the engine idle, but you will still get some useful charge if ran long enough (say 20 minutes). I don't like that idea either, because it takes about five hours of charge to get a full charge of a discharged battery and it's not a good idea to let a car idle anything near that long.

But I doubt if there would be a noticeable difference in how long the alternator lasts and the last few alternators I have purchased cost less than a hundred bucks, IIRC (all mine have been GM).


-Don- (SSF,CA)

Andrew B.
03-10-2009, 03:46 PM
I have been thinking about this more. There is a place I can safely park my car outdoors. But I tried to use my cigar lighter with my car turned off, and it doesn't work. So there appears to be no connection without the key in the car.

I asked the repair place if they have ever worked around this, and they said they never heard of these chargers.

Is there something I'm overlooking?



Or, if you don't want to bother with the IOD fuse, if there's sunlight where the car is parked a small cheap solar charger (http://www.jcwhitney.com/autoparts/Product/Pr-p_Product.CATENTRY_ID:2012890/c-10101/Nty-1/p-2012890/Ntx-mode+matchallpartial/N-10101/tf-Browse/s-10101/Ntk-AllTextSearchGroup?Ntt=Solar+chargfer)should help. The type that plug into a cigarette lighter as shown here should be all that you need.

-Don- San Francisco, CA

Ken
03-10-2009, 04:44 PM
I have been thinking about this more. There is a place I can safely park my car outdoors. But I tried to use my cigar lighter with my car turned off, and it doesn't work. So there appears to be no connection without the key in the car.

I asked the repair place if they have ever worked around this, and they said they never heard of these chargers.

Is there something I'm overlooking?

It would only require a small wiring change to work around this. At the moment your cigar lighter is wired into the 'cold' side of the ignition switch. Option 1 would be to wire in a second cigar lighter directly connected to the battery with a 5A inline fuse fitted close to the battery positive terminal. Option 2 would be to shift the existing wiring so that the cigar lighter is wired into the 'hot' side of the ignition switch. In either case the lighter would then be across the battery with the ignition 'Off'.

Ken.