Many people blame the battery when their car, boat, or other equipment won't start. However, a quick check of the entire system for corroded or cracked wires, bad connections, or rusted parts can show problems with the electrical system rather than a lazy battery. However, making new battery cables is not difficult, and you don't need complex equipment to make them.
Part 1 of 4: Take the Items
Step 1. Raise the hood and check the battery, as well as all connected lines and cables, for rust, corrosion, or bad connections
Before making the new cables, really check which one needs to be replaced. Remove any cables that are broken, chipped, loose, hardened, or that look bad so you know which one needs to be replaced.
Step 2. Make sure you have the same gauges for studs, lugs, and wires
On the wire, there should be a number with a bar on it, such as “2/0”, followed by the letters “AWG” (American wire gauge). The terminals must also have a separate number with a bar. This represents the size of the gauge. However, the terminal may not have the letters “AWG”. Make sure you buy both the positive and negative terminals.
- If your cables don't match the battery, you can also get cable staple adjusters, which will tighten around any cable to ensure a good fit.
- Non-adjustable or “universal” terminals should only be used as a temporary solution.
Step 3. Choose the appropriate cable for your equipment, in the gauge size stated at the top
Different cables must be used in different equipment. While there are many options, the general strategy is easy to remember:
- Land transport (cars, tractors, etc.) you must use raw copper wire.
- Maritime transport (boats, jet skis, etc.) You must use galvanized filament (tinned wire) to avoid rust.
Step 4. Purchase a roll of non-acid or active flux core of welding wire
Resin core solder wire is the safest to use for battery connections. Active core or acid lead wires can cause problems and corrode the battery when exposed to electricity.
Step 5. Take some flux paste or flux for the connections, again ignoring active or acid flux pastes
Like solder wire, this paste is too corrosive to be used with copper or tinned wire.
Some companies actually sell pre-loaded flux and solder posts
Step 6. Alternatively, use the faulty cables to buy replacement parts at your local auto or hardware store
Carry the faulty battery cables to make sure you get the correct parts for your car or boat if you don't know which ones to buy. If in doubt, ask a store clerk about replacement parts. It carries the make, model and year of the car to help them know the specific engine. You will need to:
- two brass or tinned wires
- two terminal nuts
- two terminals
- paste or resin flow
- Insulating liner, cut into four 6-inch pieces.
Part 2 of 4: Prepare the Cables
Step 1. Use a thick pair of wire cutters to gently grip the wires
Don't try to cut the wire with a serrated knife, as this leaves the ends jagged and uneven and they become difficult to work with. Use a sturdy set of cutters to cut through the wire in one short, smooth motion.
Step 2. Trim the end portion about 1 inch (3 cm) away from the rubber jacket to expose the cable
Cut smoothly, trying only to cut through the rubber covering and not the strand of the cable underneath. You can use the nuts on the post (the piece that is attached to the battery) to figure out how much to trim. Just line it up with the wire and check the length of the hole, then trim enough rubber so that the metal wire fits snugly.
Don't worry if you trim too much, you will re-wrap the cables later
Step 3. Using your fingers, gently remove any loose or uncoiled strands from the cables before use
Removing these loose tips will decrease corrosion and greatly increase the life of the cables.
Step 4. Add two 4- to 5-inch pieces of heat shrink insulation to each wire, pulling it out of place until later
The liner is more difficult to put on after the posts are clamped, so during this step, slide it over the wire and unroll it over them, toward the center of the wire. Each of these covers will cover the exposed metal at the ends of the cable when you're done.
Part 3 of 4: Fasten the terminal nuts
Step 1. Generously apply flux paste to the inside of the exposed terminals and wires
This paste heats up and creates a strong electrical connection between the two nuts. Apply the paste generously with a cotton swab.
Step 2. Slide the stud nut onto the exposed end of the wire, pushing it in as far as you can
Some of the flux will squeeze out, but there is no problem. Place the nut snugly over the exposed wire for now.
Step 3. Press the stud nut onto the cable using a flat punch or press
If you have a pressing machine, this is the step where you should use it. Otherwise, get a flat punch or angle iron and a hammer. Place the force in the center of the nut, then hammer hard to press the stud into the wiring. Flip the wire over and repeat on the other side.
Step 4. Using a flame or other high heat source (such as from a torch), heat the nut until the flux resin is boiling
You may want to have the whole piece thin and warm. You can hold the torch up, then turn it on and twist the wire in front of the flame so that everything heats up evenly. Heat until the resin begins to bubble out of the stud nut.
This will preheat everything to make soldering easier in the next step
Step 5. Still applying heat, solder around the connection between the wire and the terminal nut
Use the non-acid, non-reactive welding wire to solder where the stud nut ends and the exposed wire begins. You can do this right after the resin is boiling. When you're done, let it cool for 1 to 2 minutes before continuing.
Make sure you have enough heat to liquefy the solder
Step 6. Slide the heat shrink insulation up to cover the exposed metal, then use the heat source to insulate it around the connection
All that needs to be exposed is the flat nut on the post that connects to the battery. The rest of the connection must be covered and tightly fitted with the liner to prevent corrosion.
Part 4 of 4: Adjust the Terminals
Step 1. Clamp the terminals in a vise, open side up
The entire terminal will get very hot and cannot be clamped or crimped in advance like the terminal blocks. Hold it so it won't move when you insert the hot wire and solder.
Step 2. Generously clean the inside of the terminal and the outside of the cable with flux resin
The "elements" required to hold the terminals are exactly the same as those used for the nuts, although the process is a bit different. Use a cotton swab to cover all parts of the posts and wire that will be connected.
If you have previously soldered and previously resin-coated terminals, skip this step
Step 3. Using the torch, heat the post to bring the flux resin to a boil
Make sure to do this in a well-ventilated area. There must be large and many bubbles forming to know that it is boiling.
Step 4. Preheat the end of the wire for 12-15 seconds, then push it into the stud
If both the wire and the terminal are hot, the connection will be much faster and more secure.
Step 5. Solder the connection between the terminal and the cable
As well as the terminal nut, solder the edge of the terminal to the exposed wire below it. Even if you have pre-soldered connections, this is not a bad idea to add security.
Step 6. Use some wire cutters to clean up any exposed wire strands
If any of the strands in the cable loosen when you insert the cable into a stud, remove them before proceeding.
Step 7. Slide the liner to cover the exposed metal, then heat it to insulate it
These liners will greatly increase the life of your battery cables.