How to Get Your Cache Battery to Charge While You Drive

Having a second battery, or cache battery, in a vehicle provides extra starting amps when the need arises. Many vehicles are equipped with extra components that can draw additional system voltage, such as powerful aftermarket stereo amplifiers, extra running lights, small compressors and trailer hookups. Dual battery setups which are hooked in parallel will allow a cache battery to charge while the vehicle runs. Both batteries will be maintained with a proper charge.

Instructions

1

Verify that your cache battery has the same amp rating and the same design as your primary battery. They should both be of the same approximate age, and of a standard model used in vehicles only -- do not mix battery types. Use wire strippers to cut two lengths of 4.0-gauge battery wire that will reach from your cache battery to your primary battery. The battery wire should not be more than 10 feet long, since it will cause too much resistance.

2

Strip the ends of each wire and connect two battery terminal connectors on the ends of each wire, by slipping the stripped ends into the cable hold-downs and tightening them with a socket and wrench. Loosen the battery terminal hold-down bolt and nut. Place the connectors over the positive and negative terminals on the cache battery. Tighten both hold-down bolts with a socket and wrench.

3

Connect two wire eyelets to the other ends of the cache battery wires and crimp them closed with wire strippers. Hook up one eyelet to the negative connector on the primary battery, making sure the same wire is connected to the negative terminal on the cache battery. Run the eyelet through the terminal hold-down bolt and tighten the nut with a socket. Hook up the positive eyelet from the cache battery to the positive terminal bolt on the primary battery and tighten the nut with a socket.

4

Place tie straps around the cache battery wires, anchoring them to an existing loom or bracket on the engine or firewall. The cache battery is now hooked up in a parallel circuit with your primary battery and will assist in starting the vehicle by providing more amps, but will use the same voltage. The same charge the primary battery receives will also charge the cache battery.