Upgrade Energy Dark Lithium RED 6S 4500mAh Li-ion

The Upgrade Energy Dark Lithium RED 6S 4500mAh is a lithium-ion battery for small FPV drones, built from six Molicel P45B cells in series (21700 format). The pack weighs 428 g and the connector is an XT60. Li-ion instead of LiPo means more energy per kilogram with less current reserve, a pack for long-range and cruise flying rather than racing.

At 6S Li-ion the nominal voltage is 21.6 or 22.2 V depending on the cell; at 4.5 Ah the energy is therefore 97.2 to 99.9 Wh, in both cases below 100 Wh. At 428 g that gives about 227 to 233 Wh/kg. 45 A is stated as the maximum discharge (Maximum Discharge): that is a limit value, not a continuous current. Related to 4.5 Ah it corresponds to 10C by calculation. The figure to plan continuous operation with is a current clearly below it; an XT60 is rated for about 60 A, so the connector is not the first bottleneck.

Below 100 Wh a spare battery may travel in hand baggage under the IATA passenger leaflet (February 2019 edition), not in checked baggage, and the terminals must be protected against short circuit, for example by the original packaging or by taping them. UN 38.3 testing is the precondition; airlines may apply stricter rules, and the current edition should be checked before travel. At 428 g the pack is far above the 250 g limit of EU class C0.

In selection the current demand of the drive in cruise must stay clearly below the 45 A limit; anyone who flies permanently near the limit heats the cells and shortens their life. Cylindrical cells in metal cans show wear less by swelling than by falling capacity, heat under load and growing voltage sag. At the seven-pin balance lead one checks the six cell voltages; a deviating cell is a warning sign. Cold reduces power, and storage is in the middle of the charge range as the maker specifies.