Battery Power - Battery Pack Voltage Reduction

by Stu Moxley

Sometimes when building a battery pack you require a dummy battery to achieve a reduced voltage. For example a battery holder designed to hold 8 batteries will get you 9.6 volts if you are using nickel-metal hydride batteries. Two of these packs wired in series will product 19.6 volts. By replacing one of the batteries with a an ordinary household fuse you can drop the volt by 1.2 volts thus achieving an 18.4 volt power source for your locomotive.

The fuse required is a Type P cartridge fuse typically found in your household fuse box and available at your local hardware or electrical store.

Why would you do this? In my case, my Radio Shack charger was only designed for 18 volts and would cut out too early with the 19.6 battery pack. By changing one battery to a fuse I am only dealing with 18.4 volts which it can handle. You can build a dummy battery with some dowelling and wire however the fuse is quick and idiot proof. Note don't worry about the amperage of the fuse the smallest they come is 15 amp. which is way more than you need or will do any good to protect the circuit.