Originally Posted By: AKSAR
Originally Posted By: unimogbert
The jumper cables I had were not capable of carrying full starting current from my battery to his. That's why they are called "booster cables" rather than jumpers (on the packaging).
You want to have big thick jumpers. The thin little weenie cables that often come in commercial roadside emergency kits just don't carry the current efficiently.

Heavy gauge cables are more expensive, but work much more effectively. I had a good illustration of that just the other evening. As I was warming my car up to leave work, a fellow asked if I could help jump his car. Temperatures were around 0 F (-18 C). When I drove over to where he was, another guy already had his thin jumpers on and they were trying to start the car. No luck. We decided to try my (heavy duty) jumpers, and finally, after some effort, got the car started.


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!