Hi Joe,
The Power 25 is basically a 4 cell motor, but as others have reported it can work on 5 cells as well, BUT.... it is not an efficient system because the esc will be throttled back quite far out of its "happy band" which is close to max and still allows for a good bit of headroom for the governor to function. The esc will get hotter when drawing high power at lower throttle settings because the output FET power transistors will be not be turned on as much so they absorb a lot more power than necessary. Some have done this and just used a bigger esc to handle the extra power, but the whole idea is to have an efficient overall power package, and that is why it is important to use a motor with the correct windings for a certain voltage.
Using more voltage, as in more cells, certainly brings down the overall current for the same amount of power (watts), but this has to be balanced with the right motor as well to create the most efficient system. The prop of course and running rpm is also included in this equation. For example if you used a much finer pitch prop on 5 cells, you may just end up in a better place, so it could work that way, but like I say, it is not ideal. You will be better off using a lower Kv motor like somewhere in the 680 to 750 range.
Recently I think that one of the most useful sets of data are the pro charts from the Cobra motors on their website. They show tests of each motor with all possible props and battery cell counts. So find a similar motor to the Power 25 like the 2826-10 for example, and have a look at the data. Just note that the figures are for a full throttle setting and we typically operate lower. What you will see however is that as you go up in voltage to 5 or even 6 cells, then the prop gets smaller and has a finer pitch. My AXI 2826-10 has the same specs as the Cobra and I run a 12 x 6 prop at around 9000 rpm. The system is happy like that.
Keith R
Topic: E-flite 25 & 5S (Read 3421 times)