Quote Originally Posted by milton View Post
I have looked at the back of the Tender, which is clearly marked for input as 110V and without a switch for different voltage settings. I don't remember what the frequency spec is. Need to go home and check. Just looked up the Wikipedia and found that China is 50hz versus the States at 60hz. The converter is marked for frequency range 50hz to 60hz. Now I am wondering what that "frequency range" means. Does it mean that it doesn't care what the input frequency is as long as it is in the range, in which case the voltage will be stepped down as advertised? But does it also convert the frequency from 60 to 50 (unlikely)? Would the tender (actually a Battery Tender Junior, rated output 12V 750mA) survive the 60hz? Argh, headache.
The converter is rated at 100W, which should give it plenty of head room.
That frequency range means it is suitable for 50 to 60 Hz rated frequency with usual tolerances of +- 10% appr. 45 to 65 Hz, so no problem.
It will step down the voltage as specified (hopefully ) but highly likely it will not change the frequency. Since you bought the tender in the US, it should be made for 60Hz, and as long as the frequency doesn't go over 70 and below 40, you'll be fine.