Without seeing what battery is being charged it's kind of hard to say. If it's a standard H battery the charge rate is a little low at 4.1A. 4.1A would be a 1C charge rate for a 4100mA battery while the H battery is labeled at 5400mA, which would normally be charged at a 1C rate of 5.4A. Yes, an H battery is a 4s, and the nominal voltage of a 4s battery is 14.8V.