Does 20W lamp tube affect the 30w inductive ballast?
Friend, this is ok, you use 20 watts of ballast lamp tube scintillation means your city electric power is depressed. You put 30 watts in, raise the starting current of the lamp tube, this is fine, do not affect the lamp tube in use, it is only a few more than 20 watt rectifier. If you want to solve this problem, you can also change the inductance ballast to electronic ballast, just for 20 watts, the electronic ballast can be low pressure is up and running, and no noise, start quickly, to resolve the difficulties such as start. You might as well refer to it.
20W lamp tube with 30W inductance ballast, can be used but the current is slightly larger, can affect the life of the lamp tube. But if the supply voltage is not 220V, then it's not.
It doesn't have any big impact, it doesn't charge, because your load is 20W not a 30W rectifier, it's a big horse-drawn car.