Apropos to this thread ... I was just flagged down in a drugstore parking lot by a lady whose older Jeep wouldn't start.

No problem, went for my tool bag ... and realized I had tossed it in another vehicle that I'm repairing. But packrattery has its rewards -- I had a lightweight set that I got for free, and they were still stuffed under the seat. They barely reached with the vehicles touching, but we got her going first time. Even found a good frame ground on the first try; that never happens.

So there's my good deed for the day (which never goes unpunished, you know, so I'm a little wary).

One trick I have seen that seems to work fairly well is to touch bumpers so there is no need for the black cable at all. Only works on cars that have metal bumpers though, and a lot of them no longer have exposed metal bumpers.

One more reason to always park your car–when possible–facing out of the parking space/driveway/garage.

Far easier for a friend or helpful good Samaritan to assist you.

2ga isn't very common to find but 4ga should be easy enough at any decent auto store. 8' is too short, 12' length is common but better to get the 16' or even 20' foot length because you may not be able to get close enough to reach. (Mine is the common 6ga, 12' variety). Besides the jumper cables, you want to have a terminal brush and wrenches. If you can't start a vehicle right away, clean the terminals and re-secure before attempting the jumper procedure. Terminals are subject to corrosion and may even vibrate loose causing a poor electrical connection.

Running the charging vehicle at low revs (1500) for a few minutes will help bring a discharged battery alive. Remember, AFTER getting a boost, make sure you drive and recharge the battery for a while to make sure you don't need to re-boost. Then check to find out WHY you needed a boost in the first place! If you simply forgot the headlights on that's one thing but what if your alternator belt is slipping and you aren't fully charging? Perhaps your battery is too old or needs servicing? Or perhaps you have a nicked or cut wire or the terminals have vibrated loose?

PS I kinda smiled when you mentioned 0*F, that's only the beginning of cold where I live and it gets a whole lot colder than that. Canadians and northern US states also are used to having block heaters installed. It is simply a 500-800 watt replacement for an engine block frost plug that allows you to keep your oil warm and make it easier to turn the vehicle over. To go along with this, I have a 70-100 watt battery "blanket" that wraps around the battery to keep it warm. A warm battery is a lot easier to start.

I recently replaced my 6-yr old OEM battery. It was a size 40r with only 590 CCA (cold cranking amps). It was merely "adequate". I replaced it with a Canadian branded (Motomaster Eliminator - way better than Sears!) 700 CCA battery the same size. The extra juice means, I can turn over a cold engine even in -40* weather. It came in handy the other day when I had to start my car in -25*C after sitting for 4 days without "plugging in". I am very much a fan of oversizing batteries for cold climates!

Roar,
I wasn't intending to brag when I mentioned 0 F (-18 C), it just happened to be the temperature at the time I helped the guy jump his car.

Anchorage is about 61 N Lat, but has a strong marine influence, so tends to be somewhat warmer than the interior. I think the all time low for Anchorage is somewhere around -30 F (-34 C), but more typical lows this time of year tend to be in the range of 0 F to -20 F (-18 C to -29 C), depending on what part of town you live in (the east side of town typically being colder). Fairbanks and the interior get much colder than Anchorage, and most folks up there have block heaters. The coldest ambient temperatures I've personally experienced was -60 F (-51 C), but that was when I was up on the North Slope at Prudhoe Bay.

I've had both block heaters and battery blankets in the past, but I have found I generally don't find I need them in Anchorage, especially since I now park the car in a garage at night. With a decent battery I haven't really had any issues at typical low temperatures in Anchorage, except when I've done something dumb like leave a dome light on.

In addition to carrying a set of long, heavy gauge jumper cables, I've also put battery pack jumpstarters in both cars. It's very easy to deploy, allows one to self-rescue if you need a jump, and can run your cellphone or other devices for quite some time. Just make sure you follow the directions about keeping it charged.

I learned the hard way about 10 years ago about keeping those Emergency Jumpers plugged in and charged - I had one that I hadn't plugged in for about a year, and when I needed it, it didn't work. I've read you need to top them off every 30 days or so.

The ones I have from Costco state in their directions to charge them immediately after use and at least every thirty days. I have a Monthly Battery Maintenance Procedure where they both get charged, along with the emergency cellphone chargers and the ham radio HTs. Quarterly I rotate and recharge the battery in my shotgun's weaponlight along with any unused Eneloops. Stuff that's being used gets charged more often as appropriate.

Mine went completely dead after about 5 years. I called the manufacturer. The tech said the huge battery in it has a shelf life of 5 or 6 years, no matter how you treat it. He was actually kind of laughing at my ignorance.

I used it exactly once over the five year period. I won't be buying one of those devices again. I don't know how long it has been sitting on the store shelf. Also, I would need to replace it after 3 years or less in order to ensure it will be working when I need it, and that's assuming it was sitting on the store shelf for no more than a year.

Anyone know if there's a "Smart" charger for jumpers similar to the high-end chargers for AA batteries which give information re. battery life, charge level, etc?