To use the network charging feature, you need to connect two EOS-0610iNET chargers with the option cable #HP-EOS0610-MSC. One charger becomes the master and the other the slave. The master charger is used to set the charge parameters, while the slave charger automatically adjusts to the master settings. When all is connected and the master settings have been made, long press ENTER and then DOWN key to change from SOLO MODE to SYNC MODE. Long press ENTER to start BATTERY CHECK. Each charger will show a number of cells on its own screen for confirmation. If both are correct, short press ENTER to begin charging.