Swaytronic Paraboard. Application. The simplest and safest solution to charge many batteries at the same time. The Paraboards make it possible to charge up to 6 or 8 batteries with the same voltage via one charger output. The Paraboard circuitry ensures that the batteries are all charged in a nicely balanced manner. Batteries with different SOC (State of Charge) can be connected.... Customer Benefits. Charging up to 6 or 8 batteries via one charging output delays your charging effort, especially with multiple batteries. There is no need to reconnect when the battery is charged and your batteries are all charged cleanly and balanced.