• Perhaps it should be mentioned for the benefit of newer folks that the original question had nothing to do with 3S vs 4S (increased voltage and thus increased RPM/performance) but was asking about increased amperage (mAh capacity and thus longer flight time). The electronics and motors couldn't care less about capacity. Mr. Pixhawk has no idea if he's being fueled by a 2000 mAh 3s or a 8000 mAh 3s. But the latter may leave the aircraft unable to get off the ground, or make it handle like an Emu. So, the considerations for battery capacity/size are totally dependent on weight and sometimes physical size/shape, and their effects, and nothing else.

            Generally mass-produced R/C aircrafts' battery sizes are the result of striking compromises between performance and endurance and weight and lifting capacity and so on. A particular aircraft's balance of these factors can often be altered by changing to a different size battery (paying attention to maintaining a proper center of gravity). A bigger battery, up to a point, will result in longer flight times, but less performance and lifting capability. A smaller battery can turn a sluggish aircraft into a hotrod, or increase payload, but at the expense of shorter flight times. Those of us who build or customize our own multicopters rather than flying off-the-shelf vehicles spend a lot of time deciding what batteries to use, and it's not as simple as it might seem (and voltage, along with discharge "C" ratings do of course also enter the picture).

            • "Mr. Pixhawk has no idea"

              Lets hope Mr Pixhawk does because that weight change from 2000mAh to 8000mAh is going to have a dramatic effect on handling and flight time =)

              • Nope, Mr.Pixhawk probably thinks his boss is sitting on him when he whirls his props wildly and goes nowhere! No, folks, it won't work to take your car's battery out at the field and bolt it to the bottom of your Proto X! LOL

  • Of course, take a look at Note that increase in weight from the battery will affect performance. I dont know for sure but generally it should be fine to use a 4S.

  • Anyone?
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