Hi everyone. I'm new to multirotors and have a question regarding batteries. I've built the 3DR Arducopter kit with APM 2.5. I've been using 3 cell, 11.1v 2200mAh lipo batteries. I am able to get 9-11 minutes of flight time per battery. I'd love to be able to get more flight time.
I've read several sites about batteries and understand them this way - lipos have 3.7 volts per cell, thus a 3 cell has 11.1 volts. Capacity is measured in mAh. The higher the number the higher the capacity.
So here's my question - as long as I stay with a 3 cell 11.1 volt battery, can I upgrade the mAh number? I saw some 5000+mAh batteries that were 11.1 volts and assumed that one of these would give a longer flight time. True?
Also, I've come across some cables that let you run 2 batteries in parallel. Obviously this adds more weight, but is this another good option for increasing flight time?
Once you've tried 4S, never go back.
Thanks for the replies. I just didn't want to overpower and burn something up. Since my post, I've looked at what I have plugged in on my Arducopter - The APM Power Module says it has an 18V max input. I'm assuming that the little circuit board on the Power Module is what regulates the power going to the APM 2.5, so as long as I stay under 18V I'm good. The ESCs in my kit specify "2-4 LiPO, 5-12 NIHM/NiCd" in the battery section.
Starting to understand this stuff more and more each day, thanks to this forum!
The heavier the airframe , the more power you need to burn. More capacity also means more weight.
The ESCs that I have are rated for 2-4 LiPO, if I use a 6 I'll kill them, right?
Right now with 4s I'm over powered for ESCs as they are GetFPV Lumenier 30 amp ESC with SimonK Firmware at I was running 5000ma 3s with 13 x 4 props on NTM 3536 910kv.
eCalc has the NTM 3536 910kvs rated at 520 watts vs the specs on HK at 350 watts so I'm kinda wondering....with the 3s I was getting a safe 291 watts max power, with the 4s same 13 x 4 props I'm at 473 watts max power but definitely over the ESC limits at 38-40amp at full power. I have some Turnigy Trust 45s with SimonK I'll switch to today. Then my only real question is what the actual rating of the motors is. Hover on 4s is only 102 watts and my type of flying for video should keep me well below even the 350 watt HK spec.
With the 4s 5800ma batteries the eCal it says I should drop down to 10 x 6 to be below 30 amp max power ESC limit but brings me back to a < 8 min safe flight time. But puts the hover throttle back at 51% and the max watts at a very acceptable 362 watts. I may decide to compromise and go with 12 x 3.8 carbon props for more reserve power.
The other new issue after the switch to 4s with the same props is my hover throttle is now 32% so in Loiter it climbs so I will need to adjust the hover throttle setting in the APM once I decide on the prop ESC combo. I already tried 10 x 4.5 props but the PIDS were off with the quad twitching a lot, I didn't want to have to redo them an I have a lot of 13 x 4 props I've invested in all ready.
The orange ball is Styrofoam from craft store with 1/2 balsa tail boom. This feature has been a HUGE success in orientation!
*** If anyone knows about the actual Hobbyking NTM 3536 910kv max watt rating please chime in.
Also I need a step down transformer to power the Fatshark FPV anyone know a good light weight unit?