According to John Hay, UNL Extension Educator, dead batteries are more prevalent in winter because cold temperatures tend to sap available power. For example, in 80 degree weather a battery has 100 percent starting power. However, at 20 below zero, the battery has about 30 percent starting power.
Before jump starting, check battery cables to make sure they are well secured and free of corrosion. Then identify the positive and negative terminals on both the dead battery and the battery to be used for the jump start.
Take extreme caution throughout the process to prevent a possible explosion. The ignition spark must be kept as far away from the electrical connections as possible because the battery releases combustible gasses. Also, an operator should open the battery caps (if possible) to make sure the solution inside the battery isn’t frozen. Never attempt to jump start a frozen battery because explosions are more likely to occur.
To begin the jump start, connect the jumper cables to the positive terminal on the dead battery and then to the positive terminal on the live battery. Next, connect the cable to the negative terminal of the fully-charged battery.
The final connection causes a spark, so the cable should be kept away from the dead battery’s negative terminal. Instead, the cable should be attached to the frame or body of the dead vehicle to give the spark distance from the dead battery. Never hook the jumper cables directly to a starter, especially on a tractor. If the vehicle is in gear it could start and run over the person initiating the jump start.
Once the vehicle is started, reverse the process to take the jumper cables off of the vehicle. Remember to keep the spark away from the batteries, and the vehicle should be ready to go.
