How to Wire 3V Watch Batteries Together

The soldering iron is the only tool you need to construct variable power supplies with 3-volt batteries.

Sometimes the design of the machine you're working on, budget constraints or other factors conspire against you and force you to create a relatively larger power supply from a number of smaller 3 volt batteries. When that happens, knowing how to wire these diminutive batteries together to create a variety of power supplies can come in mighty handy.



Luckily, the theory behind and practice of series and parallel battery-wiring is simple enough to understand and execute.

Things You'll Need

• 3-volt battery holders
• Soldering iron and 2 percent silver solder

Instructions

1. Put each of your batteries into a separate battery holder and lay them side-by-side.

2. Solder the battery holders to one another negative-to-positive, left-to-right (in "series") to create a power source equal to the sum of the batteries' voltages, but with the amperage of a single battery.

   For example, three 3v batteries with 200 amperage wired in series this way would create a power source equal to single a 9v, 200 amperage battery.

3. Rearrange the rows of battery holders into vertical columns. Solder them together positive-to-positive and negative-to-negative (in parallel) to create a power supply that equals the voltage of a single battery, but the combine amperage of them all.

   For example, three 3v batteries with 200 amperage wired in parallel will create a 3v, 600 amperage power supply.

Tips & Warnings

• You can mix these wiring styles to create an endless variety of power supplies.

References

• Other Power: Battery Wiring
• ZBattery: Connecting Batteries in Series or Parallel