Why do folks not understand ohm's law?

[skellyo]

Originally Posted by sleebus.jones

*raises hand*

That's exactly what I did with my T4. In all of my messing around, I've settled in on 40 mph as being my "happy top speed". May be slow for some, but it's fine for me. Gets the job done and breaks less parts. So yes, when I add cells, I gear down. I add cells to get the efficiency advantage of running higher voltages. I ran a 2S A123 in there, but wasn't happy with it. I put a 3S A123 in there, and then geared down to something crazy like a 13T. I'm keeping the load (work) the same and increasing voltage, so yes, my amp draws went down.

Eventually I went to a 3300kv motor, because the 5700kv really limited my choices, and I got tired of hearing the car sound like a dentist's drill as it went by. I still geared for the same speed, so I'd assume my amp draws would be very close to the same, since I would be doing the same work.

IMHO, if you have a ESC capable of running 6S, you're throwing away efficiency if you run at 4S. That's why I run all of my rigs at the highest voltage I can. Otherwise it's like buying a 10MP camera, and then shooting everything in 640x480 because you don't want to buy a big memory card.

I do agree that if you add cells and do not change the gearing, you amp draws will absolutely NOT go down, they will do exactly as you show.

I completely understand your rationale. I'd probably do the same if I didn't already have a ton of 4S packs already.

[othello]

As already mentioned gearing and choosing the right motor kv is important otherwise your amp draw will run out of hand especially with high voltage.

I also gear for 38-40mph and can achieve this with 8-11s A123 using a Neu 1515/2Y (1100kv) in my truggy. As i can not influence startup power with my ESC, gearing and cellcount are the methods of choice to influence speed, amp draw and thus power output.

[lutach]

A lot of people don't have the usual and nice common sense most do. Sometimes even simple ways of explaining something will not click on those people. I hope this and many other threads like this will teach people some common sense. I hope manufacturers too can learn something as they like to advertise crazy numbers just to impress everyone, but forget the danger that is also involved.