Tony Cundy 2

I am new to electric flight and wonder why there are so many inconsistent units.   We all talk of charge current and discharge current in Amps.  We think of discharge times in minutes but it is not too difficult to think of 12 minutes as 0.2 hours.  So we can see that a 2 AmpHour battery can discharge at 2 Amps for 1 hour or 4 Amps for 30 mins or 40 Amp for 3 mins, so long as Amps and hours multiplied together comes to 2 for our 2 Amp hour battery. Of course this is a nominal value and there is some inefficiency in the charge process so we might have to charge our 2 Ah battery at 2Amps for 70 minutes - of course the clever Li_Po charger will sort this out. With all this process worked out in Amps, it seems daft that battery suppliers complicate a simple world by giving their capacities in mAh - that is Miliamp hours.  All this does is add an unwelcome layer of complication.  Surely it would help us all if suppliers said 2Ah instead of 2000mAh. Car batteries and other batteries with discharge rates of several Amps always give capacity in Ah.  Let's leave mAh to low power torch batteries that discharge at perhaps 50mA. This is one of many inconsistencies that makes life harder than it ought to be.  How about dimensions in inches and wing loading in ounces per square foot.  The inch to foot conversinn is enough trouble but where does this leave models weighed in pounds those who use the metric system?  I could fill a book.     

I have just come to Electric R/C after Free Flight in the 50s. Can anyone tell me why the balance lead on a FlightPower Evo25-15002S has one black and 3 red leads. The black seems to be battery -ve (0v), the first red is inter-cell (3.7v), and the second red is battery +ve (7.4v). The third red seems redundant and to need no connection to the balance charger. Help please!