1) The 3 switches should remain to be in off position when the
tank is being charged.
2) The voltage indicator is used to check the voltage only. It
does not matter whether it is on & off.
3) The toggle switch besides the charging slot should be in on
position during recharging.
4) The led light at the charger should be red in colour when
the toggle switch is turned on.
Sorry for typing English because my Chinese writing pad is
temporary out of order.