mspaul

I will be away for 3-4 weeks and was thinking of getting a battery maintainer to keep the car battery fresh.

Any recommendations for make/ model/ type?

joelaff

I have had very good luck with BatteryMinder:

http://www.batterymart.com/p-battery...y-charger.html

However, I am not sure if it is safe to connect it with the battery in the car. The BatteryMinder folks seems to think it is, if the battery is already charged. However, the MB manual says not to connect anything to the battery while it is connected to the car.

Honestly, I doubt it would cause a problem.

weinschela

I use a Battery Tender Jr. for a car (Audi) that is garaged but used very infrerquently (weeks between uses). It trickle charges; has a quick connect between the crager and the battery, both alligator and ring connectors (the latter if you want to leave the battery side wires connected between uses. It works very well.

DanG2

I've been using a Battery Minder Plus

http://tinyurl.com/2y5fnb

It will handle up to 5 batteries, so I bought two extra lug harnesses

http://www.batterymart.com/p-12-volt-lug-harness.html

found a 2-Conductor Automotive DC Accessory Cable at Radio Shack

http://tinyurl.com/2ym7k5

cut the accessory cable in the middle, and crimp spliced the ends (connecting the two shielded jack sides of the plugs to each other) to a length of zip cord long enough to go from the battery of one car to the battery of the other in the garage.

I have two lug harnesses on the battery of the first car (one harness comes with the Battery Minder) and one on the second car. So I can now plug the Battery Minder into one harness on the first car, run the zip cord from the second harness on the first car to the harness on the second car, and keep both batteries charged up at the same time. As long as both car's batteries are about the same voltage, there won't be a problem when you make the connection.

I've used it on trips of up to a month over the past three years, including as recently as a trip we returned from just last week. I'm sure there are other ways to do it, but this has worked well for me, and I'm satisfied with it.

Dan

P.S. Just noticed you got a reply from Joelaff while I was working on this. As noted, I've had no problems connecting the Batteryminder while the battery is in the car. It only puts out 1.3 amps, so unless the battery is completely flat with an dead cell, I don't see how it could feed back anything into the car's electrical system. Anyway, another vote for the Batteryminder.

jallison12

I think my uncle has this:
http://www.autobarn.net/vec080.html
to keep his Porsche charged. He just plugs it into the cigarette lighter socket. So, no need to get under the hood looking for the actual battery.
jim

mspaul

I guess I would go with battery minder plus.

As I am new to all this, can any of the battery minder users shed some light on the usage process.

-What battery will it connect to - the one in the trunk?

- Any precautions that I should take.

I had got both my batteries replaced a month back when I was in for servicing as both of them failed the battery test (at least this is what the SA said). And would not want to go through this again when I come back from my trip.

Thanks for the replies.

Flash Gordon

Unless you live in a much colder climate than where you are now, it is really not necessary for you, especially you have new batteries. I have been away for more than 3 weeks in Jersey in December and the batteries were fine when I got back. Of course, the cars were in the garage, not heated just insulated. My 2 cents.

ohlord

weeks,unless you are sure your system has no ground leaks in the wire system,and most cars do.4 weeks may run the battery down which shortens life and if down low enough you loose all the settings.
Any good 2amp trickle charger with overcharge protection will do,and just hook it up to the underhood jump terminal and a good ground.
go and enjoy the trip
costco
sears
etc.
just make sure the key is out of the ignition,while on maint charge or any time you need to charge the battery.

joelaff

Allowing a car battery to discharge, or sit without a full charge is quite bad for it. This can lead to sulphation on the plates, which reduces the power output. So, yes, it is best to stick it on a trickle charger, like the BatteryMinder, etc.

bigmel

How about just disconnecting the negative terminal from the battery. shouldn't the battery hold the charge for a month? I remember I was away for 2 months playing soldier and I removed both terminals and tape them up. when I got back I just reconnect the terminals and the car was good

DanG2

Yes, the lug harness connects to the battery in the trunk. Just unscrew the nut from the bolt at the battery terminal, put the appropriate ring terminal of the harness on the bolt, and put the nut back on the bolt. No precautions are necessary, except the usual ones about watching polarity and not shorting the positive terminal to ground. You don't need to remove the terminal, just the nut, so the battery remains connected while you're doing the installation.

joelaff

I should think you would want to connect it directly to both batteries. There is quite possible a diode between them, which would prevent charging one from the other.

Jon2007E63P30

http://www.pulsetech.com/

These guys have some extremely good patented technology for treating your battery right. Most of their business is military contracts.

Taiwanese

anything from Walmart or Sears will do.