Know your battery! Check your receipt, if you still have it, to learn the battery’s age. Batteries have a way of “aging” because, once installed, they are out of sight. One of my VW friends told a group of us recently that when he could not start his car, he inspected the battery and found it to be 10 years old! Well—that’s a ripe old age!
So get that detail out of the way first.
If you have a test meter, check the voltage on your battery. It should read at least 12.50 volts and as much as 12.7 volts, depending upon its age and charge. When a battery drops to 12 volts, it will not function as designed.
If you do not have a test meter and/or cannot charge a battery, it’s best to simply remove the battery and take it to a battery shop to have it tested and charged, if necessary. Battery shops can do it all, including selling a new battery if the need arises.
If your battery appears to need charging, remove it from the car. I like to use nitrile gloves when handling the battery, if it is of the liquid type, because it is more than likely to have some acid residue on it. Don’t get this onto clothing or anything else. Battery acid is ‘hungry”. I loosen and remove one of the cable connectors and push it out of the way of the battery so that it won’t stray onto the pole and spark. When loosening the connector bolt, do not allow the tool to touch metal and spark.
I like to use a large piece of cardboard box in an open area for doing the charging.
Place the battery onto the cardboard because the liquid will bubble into tiny mist-like droplets as the battery charges. The cardboard will catch these. Then dispose of the cardboard when the process is completed.
Clean the battery posts. If you do not have the tool for this, use sandpaper for the purpose. Make each pole nice and shiny.
Given that this is a liquid-filled battery with removable caps, remove the caps and fill each cell to the indication in the hole. Use distilled water.
Run a heavy-duty extension cord to the charging area. Leave the caps off the liquid-filled battery to avoid building gas in the closed cells. Connect the charger to the battery first. Then plug in the extension cord.
Try charging the battery on a slow charge—usually 2 amps on most home-owned chargers. Leave the battery charging in this slow manner but check it from time to time. The meter on the charger should alert you to the progress.
Meanwhile, you can do some “homework”. Inspect the battery compartment. Remove the nut and washer and the clamp. Are they rusted? If so, clean them thoroughly. Also, clean the stud where the clamp fits. Clean the area where the battery sits.
You can neutralize any light corrosion by using a solution heavy with baking soda and water. Pour a little bit onto the corrosion and allow it to bubble I hope that you still are using the nitrile gloves and are avoiding getting any of the corrosion onto your clothing or anything else.
Use paper towels to clean the area and dispose of them into a trash container. Once I have removed this residue, I pour a little fresh water onto the affected area, then use paper towels to dry it.
Note the condition of the Ground (Negative) Strap. Is it corroded? If it is corroded it will show blue-ish-white deposits. Remove it completely and soak in a baking soda-water solution. You will see the baking soda begin to bubble away the corrosion. After a lengthy soak, remove the strap and thoroughly rinse, using water. Best to do this outdoors because it’s a little dirty to do in the kitchen sink. Allow to dry well. If you have compressed air, you can dry the strap more quickly.
If the Ground Strap is frayed and appears to be fragile, it’s time for a new one. Go for a good one because you will want to have excellent conductivity.
Check the condition of the bolt holding the Ground Strap to the body. If it is corroded, remove and replace with a new bolt and washer–or clean it well. If you have access to a tap, clean the bolt hole threads (8mm X 1.25). Reinstall the cleaned strap. Clean the insides of the Positive and the Negative (Ground) connectors. There are tools for this job but if you don’t have one, you can use a piece of sandpaper. Roll it into a cylinder and turn it round and round inside each connector until the metal appears shiny and clean.
Note the condition of the Positive Cable—is it in good condition? Are the wires well connected to the connector?
Some battery chargers will alert you to a full charge with an audible sound. Others may have just the meter. Once the battery is fully charged, first unplug the extension cord—then remove the clips from the battery. Use a paper towel to clean the top of the battery to remove any acid which may be there from the charging process. Clean the caps and reinstall them.
Set the battery into the battery box with the poles according to the correct connectors—plus is for the Positive Cable and minus for Negative—the braided Ground Strap.
Before connecting the cables, secure the battery into its place using the clamp. Now, you are ready to connect to the cables.
Double-check before actually connecting to be sure that the battery is positioned properly—it does happen, occasionally, that someone will put the battery in backwards. Once the connectors are in place, tighten them for the best conductivity.
Someone posed the question about sparking when the second cable is connected. This is okay. Put the last cable firmly onto the second pole and push it into place—it may spark a bit when it initially touches. No one has ever come close to dying from this! Then tighten the bolts on both. While doing so, don’t allow your wrench to touch the car frame or you will get a good spark!
IF you find the need to purchase a new battery, make sure that the shop knows the proper make and model of your car. You want the proper-sized battery which will fit into the battery compartment.
An over-sized battery can touch the seat-bottom springs and short. Furthermore, it may not seat in the battery box to be clamped into place.
Now go out and drive your Beetle with contentment. You’ve just resuscitated it.