[Elecraft] Battery Charging

[Tim Groat]

Using 400Hz power is risky, because the current in the RFI bypass 
capacitors will much higher than normal. The leakage current through the 
capacitors to the output and other accessible parts will be high, 
possibly high enough to be a shock hazard. Running a 50-60Hz product 
from 400Hz power may also cause early failure of those capacitors.

Follow the charger's marked input frequency rating, which almost always 
will be 50-60Hz. A small variation for the tolerance of a 
motor-generator is acceptable, but 667% of the maximum rated frequency 
is no small variation!

--Tim (KR0U)