How to Replace a Car Battery

on 6/27/2007 The comments submitted here are outstanding pieces of information but I'd like to ask for guidance about a comment made under "tips and warnings."

"Make sure the battery is fully charged before you buy it" is a great tip and I have thought about it for decades but never had a solution offered. I have bought batteries under two conditions: store installed and self installed. I have always suspected that the in-store installation was installing partially charged batteries even though they always told me it was charged. But every time I brought a new "fully charged" battery home, the specific gravity was never at the point of max charge. When I called the store they always said that's the way batteries are shipped and the car's system will bring it up to maximum after a week or so depending on use. I never had a battery that ever reached max specific gravity.

What gives?

on 5/22/2007 Very Important!
Always remove the Negative (Black) terminal first when removing the battery. After the negative terminal is completely removed and pulled away from the battery post, then remove the positive.
When installing a battery, install the positive cable first and tighten it up all the way. Then install the negative cable last.
The reason for doing this is to prevent you're wrench or other tools from Arcing and Sparking, while tightening the positive, when you're wrench accidentally touches the body or any ground point. If the negative is not connected when you're tightening or loosening the positive, you don't have as much risk of causing those mini lightening strikes, burns, fires, melting you're wrench, or any under the hood fireworks display.

on 7/18/2007 — some cars require that 12 volts be maintained on the electrical system during a battery change, as does my VW New Beetle. Check with your dealer or maintenance manual. Not to do so may mess up the car's computers, which will require a trip to the dealer for re-programming. A 12 volt battery or power supply plugged into a power outlet (cigar lighter) will do it.

on 11/17/2006 If you want a professional to help you with your battery--If you feel you are having problems with your battery, and for example, you can only drive your car after a jumpstart, I recommend trying to find an auto shop that offers free battery testing along with free battery installation. The only thing you would have to pay for is the battery. (Generally around 50-70 bucks.) There are a lot of locations where they do these testing and installation services for free, so do your self a money saving favor and locate one!

on 7/16/2006 Be very careful when tightening the screws, as my wrench hit a rubber pipe which had a small metal ring and when I was tightening the positive terminal my wrench hit the small metal ring and sparks flew!