We use a standard, four-pole double-throw, center-off, toggle switch (All Electronics part # STS-71) in our Evans power cars. A standard switch can handle the power of two lithium-ion battery packs in parallel.
Soldering loop terminals to the component wires made connecting them to the screw terminals on the switch easy. To make the wiring easier to understand, the 12 terminals were divided into three columns: the left for the battery pack charging plugs, the center for the battery packs, and the right for the TE receiver.
The battery charging plugs (All Electronics part # CON-240) mate with the Aristo-Craft, lithium-ion battery chargers. They were mounted on the bottom of the car next to the switch.
The loop connectors soldered to the plugs were fastened under the left column of screw terminals.
The loop connectors soldered to the Aristo-Craft, lithium-ion battery packs were fastened under the center column of screw terminals.
Loop connectors were soldered to the positive side (anodes) of two, 3 amp, 40 volt, Schottky diodes (All Electronics part # 1N5822S).
The diodes were fastened to under the two positive terminals in the right column of the switch. The positive input wire of the Aristo-Craft, 27 MHz receiver was soldered to the negative side (cathodes) of the diodes.
A jumper was made to connect the negative input wire of the receiver to the remaining negative terminals in the right column of the switch.
When the switch is toggled one way, the battery packs are connected in parallel through the diodes and the jumper to the receiver.
When the switch is toggled the other way the receiver is disconnected, and the battery chargers connected to the battery packs.
Our club members use these power cars to run large six-axle diesels and double-headers using an MU plug (All Electronics part # CON-240) that mates with the MU plugs on Aristo-Craft diesels.
There is an article on our club web site that details the construction of this
Evans Power Car.