Painless Wiring Official Site of Painless Performance, American Made wiring harnesses for your hot rod, street rod, muscle car, off-road and everything in between. Wire it once and wire it right with Painless. painless wiring dual battery kit | eBay Save painless wiring dual battery kit to get e-mail alerts and updates on your eBay Feed. + Items in search results. 40112 Painless Wiring 40112 Dual Battery Control System Solenoid Kit. 100% Return GUARANTEE -FAST Shipping - LARGE Selection. Painless Wiring 50102 Universal 30 Amp Fuel Pump Relay & Harness Kit. Brand New.