rcfs

Does anyone know how many lipo cells a KONDOR XL 20-37 motor can handle safely? Thanks

ron_van_sommeren

Motors, unlike ESCs!, can handle any voltage in RC land, as long as current & power drawn and rpm don't get too high.
The wire insulation/laquer/resin can withstand several hundred volt.

So the max.voltage depends on the prop: the higher the prop load and/or on Kv (→higher current), the lower the max. operating voltage (→lower current).
Therefore: what prop would you want to use, what velocity konstant Kv? With those numbers you can calculate rpm, current and power drawn.
Using e.g.
www.ecalc.ch
or
www.rcgroups.com/forums/showthread.php?736782-Scorpion-Calculator

Voltage/prop combination tables are merely suggestions.
To keep current and power drawn in bounds, the highest voltages should go with the low-load prop, the high-load props go with the low voltage.
All this because current drawn goes up with pitch, voltage² Kv³ and diameter⁴

Although velocity_konstant_Kv has a massively disprportional effect on current (squared) and power (cubed) drawn, Kv, measured/expressed in rpm/volt, says nothing about a motor's max. current and max.power ratings.
Both the motor in your electric toothbrush and the motor in a 1:1 train can have th same Kv.

*****

A very long clearance sale, originally 200+$, versatile, high quality, now literally peanuts:
Hyperion Emeter II wattmeter with local&remote logging, optical&electrical rpm meters, servo tester - RCG

Without a watt/volt/current/multi-meter you are in the dark.
Until something starts to glow

• To trust is good
  • To calculate is better
    Will get you to say within 10%, if input ok.
    e-flight calculators & propdata (compilation)
    • To measure is a must
      A watt-meter will more than pay for itself, several times over, your battery, ESC and motor will love you for it.
      After calculating, always check/measure current when you have a new/changed setup.
      Will also help you find optimal setup.
      And it's a great tool for debugging your power train.
      • About watt-meters and how (not) to use them, by RCG user vollrathd:
        www.wattflyer.com/forums/attachment.php?attachmentid=117297
        • A very long clearance sale, originally 200+$, versatile, high quality, now literally peanuts:
          Hyperion Emeter II wattmeter with local&remote logging, optical&electrical rpm meters, servo tester - RCG
          Contents
          • Closing out at
            • Reviews by Bernard Cawley and Ken Myers
              • Tech info & help threads
                • Increasing max.current, double, triple, simple and cheap
                  • Software and manuals downloads
          • Careful!
            (Always!) keep battery-/watt-/multi-meter wires short:
            Too long wires batteryside can kill ESC over time: precautions, solutions & workarounds - RCG

ron_van_sommeren

So the max.voltage depends on the prop: the higher the prop load and/or on Kv (→higher current), the lower the max. operating voltage (→lower current).
Therefore: what prop would you want to use, what velocity konstant Kv? With those numbers you can calculate rpm, current and power drawn.
Using e.g.
www.ecalc.ch
or
www.rcgroups.com/forums/showthread.php?736782-Scorpion-Calculator



Prettig weekend Ron
• Without a watt-meter you're in the dark ... until something starts to glow •
• E-flight calculators • watt-meters • diy motor tips&tricks • Cumulus MFC •