Combining batteries enables you to boost the output voltage so you can power electrical items that need to operate on increased voltage. The method is called “Series” and combines the voltage produced from each individual battery. For example, if you combine four six-volt batteries in series, you get 24 volts. The method is often used in marine vessels and recreational vehicles where higher volts are needed, but it’s equally useful to combine the voltage of smaller batteries to power items such as remote-control models.
Ascertain the voltage needed to power the device using your combined batteries. You can find the voltage on the label of the device.
Select the number of batteries you need to equal the voltage of the device you want to power. It’s important you combine batteries that all produce the same voltage. For example, if you need six volts, you can use four one-point-five-volt batteries, but they must be the same size, so it’s fine to use four AA size batteries, but not two AA size and two AAA size — because while the voltage is the same, the capacity is different, meaning an AAA battery will go dead long before the AA battery.
Cut a several strips of AWG 16 wire using a knife. You need two strips long enough to connect between the combined batteries and your electrical device and some three-to-four-inch strips. Measure the distance between the device and you batteries using a ruler or tape measure to get an accurate distance.
Work out how many short wire strips you need, based upon the number of batteries you’re using. The number of short strips is always one less than the number of batteries, so if you’re using three batteries, you need three short strips and so on.
Use wire strippers to remove one-quarter-inch of outer plastic off the ends of all the strips of wire. You need to expose the inner cooper metal, so you can attach them to the batteries.
Place suitably-sized elasticized bands around the batteries you’re combining so the bands hold all the batteries together in a pack. Three works well, one near the top, one in the middle and one near the base.
Mark each battery in the pack numerically using a pen. For example, if you’re combining four batteries label the batteries “1” through “4.”
Place the end of the first short strip of wire onto the “+” terminal of battery 1. Hold it in place by using a two-inch strip of adhesive tape and placing it over the wire and terminal then folding the tape down the side of the battery; electrical insulating tape does the job well.
Place the opposite of the first strip of wire onto the “-“ terminal of battery 2 using tape as previously described. Attach one end of a second short wire strip to the “+” terminal of battery 2 using tape then attach the opposite end to the “-“ terminal of battery 3.
Continue to attach the short strips of wire to alternate terminals and batteries until you connect the opposite end of the last short strip of wire to the “-“ terminal of the last numbered battery. The “-“ terminal of battery 1 and the “+” terminal of the last numbered battery do not currently have wires connected.
Attach the end of one of the two long strips of wire to the “-“ terminal of battery 1 using a strip of tape to hold it in place. The opposite end connects to your electrical device when you are ready to use it.
Attach the end of the second long strip of wire to the “+“ terminal of the last numbered battery using tape. The opposite end connects to your electrical device.