Quote:
Originally Posted by Dafni
are you really sure about that?
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If you test on equal grounds yes.. mAH is mAH so unless you are pulling more C's than a battery is capable of it will hold its voltage through the entire mAH of the pack and the 5000 will win every time. Higher voltage doesn't change how much gas is in the tank (mAH). Higher voltage will reduce the amps needed to perform the same wattage which is nice if you have weaker cells, but again unless you have a 4s lipo not capable of the demand you are after it's not going hit an early LVC. Anyone who gets different results didn't do the test on equal grounds. Higher voltage w/ less amperage or higher amperage w/ less voltage, the trick is if both packs can handle the amp draw there is no advantage to the higher voltage setup other than a potentially cooler system as voltage is normally your friend. If you have a battery that cannot comfortably meet the amperage demand (low “c” rated 4s pack) you will hit a early LVC and at that point a smaller mAH high voltage battery could beat out a larger pack. But with today’s 4s 30c lipo's being the standard you won't see what you saw just a year or two ago when 12-20c 4s lipo’s couldn't handle the amp load and would go into early LVC leaving the higher voltage system running even with less mAH.
This isn't like comparing a 8s system to a 4s sytem where other things do come into play that change the relationship a bit more, we're looking at 4s to 5s.
I'll use these specs as they are most a like in size/weight
14.8v x 150a = 2220 (5000 30c)
18.5v x 100a = 1850 (4000 25c)
but to show even a 5s 4k 30c that does weigh more and again changes the relationship in the car (heavy = more work for the motor & higher avg amp draw) you may net the same output but again the weight is now a factor as it is an even larger battery so the favor would still be to the lighter 4s 5k pack. Also keep in mind if you go just off these numbers you have to reduce gearing to match the actual MPH of the 4s system to even start to compare for run time. If you run the same gearing or are geared for more MPH than the 4s system what I was saying above is what you need to pay attention too.. to figure out run times. So again you have to gear for the same MPH for this to have any effect even on the 6s + setups.. to match or exceed run times.
18.5 x 120 = 2220 (4000 30c)