A small clarification and expansion
Thanks for the reply.
But let me be more clear.
The circuit I'm talking about is the starter circuit on motorcycles and so the current draw runs between about 60 and 90 amps depending on the particular bike. When the starter is run for 5-10-15 seconds (because of the losses the bike is not starting properly and they keep cranking the motor) on some mid-90s bikes the wiring actually heats up (like very hot).
So I'm trying to give laypeople some concepts they can understand easily. I'd like to give them real data on what portion of the 60-90 amps is turning into heat. I have done clamp on current readings with the original circuits and of course the losses vary widely bike to bike. After I upgrade the circuit to all copper (and new 250% larger wire) we find that the current flow is exactly what would be expected for the wattage of 700 watts (as used on the Ducati motorcycles for example).
So my goal is to give these bike owners (across various brands, which means various makes of starter motor and various current draws) some numbers which are generic to the types of terminals they have on their bikes and not have to have a lot of different figures here and there that might confuse them.
All the bikes used plated brass and some use plated steel terminals (the Ducatis) in their starter circuit, (none use copper terminals, not even plated copper). So they all experience large losses quite quickly and when they go to their MC brand dealer they get sold a new battery for $75-$150 and for 2 months it can overcome the losses and start the bikes. But after a few months they are back where they started. This means they are eating through batteries on a 12-18 month clip and that contributes to the hazardous waste problem that affects us all (unless you think motorcycle guys are stringent in their battery disposal routines - hint: they're not).
These losses are also there on cars but because cars have batteries that are 2-3 times the capability of a motorcycle battery (usually as small as they think they can get away with for weight and cost reasons) the cars don't really have the problems that motorcycles do.
So any axiomatic type explanations would help me the most.
Things like "yes, if the terminals are the same size and one is brass then it will only flow 26% of the current the copper terminal would flow and all the rest is turned into heat".
But if a portion of the 74% does not turn into heat, where does it go?
I just want to contribute real data and not bogus BS to the dissemination of this information. In the motorcycle field I sound like I am wearing a tin hat because many of these guys have spent anywhere from $100-$1000 at their (highly regarded in the industry) dealer trying to troubleshoot why their bikes don't start and I come along and say it's due to brass/steel terminals and barely within spec wire. (as you can imagine) I get a lot of disbelievers. But every guy who buys one of my all copper kits marvels at the the fact that his expensive (or in many cases just old) motorcycle now starts in a third to a half of a second. Which to my way of thinking defines the way the battery-wire-starter circuit was supposed to work since the consumer is fixed at its stated wattage.
Again, thanks for your reply, any and all commentary is appreciated.
M./