Wiring
Wiring Diagram
I can't take credit for the wiring diagram. It was drawn by a friend and Dragonfly owner. I did give it a good going over, and it all looks quite reasonable - and much better thought out than EM's scheme.
A high-quality replacement for the 200A, 58VDC fuse appears to be manufactured by Littelfuse as part number 142.5631.6202.
Mecatecno Dragonfly Wiring Diagram.pdfSensible Wiring
One of the things that annoys me about EM's design is the wiring. It has very long wire runs, excess wire length, and too many connectors. Mecatechno has done a much better job (but it's still not up to Japanese standards).
The power wiring is about as short as would be practical to make it. Red and black connectors are used for the battery (which has been removed for photography). Battery connectors are Amass AS150. These are 7mm connectors rated for 150 A continuously. The motor connectors are Amass XT150 and are 6mm in diameter.
Battery and protective cover removed to show power wiring.
The charger connector is manufactured in China by WEiPU. It is their SP17 series which has an IP68 weatherproof rating (just short of the best IP69 rating).
A 200-amp fuse is located inside the block connected in series with the positive battery cable. The fuse appears to be equivalent to a LITTELFUSE 142.5631.6202.
Bodywork removed to show connection of battery charging cable (blue parts).
Small connectors are the same as those used by EM. They are JST's type JWPF.
Display module shown removed from its mounting location.
Closeup of display
Display
The display module shows the battery voltage, estimated battery state of charge, and ambient temperature in degrees C.
I've been told this device beeps when the battery is below 50 volts.
The unit can be turned off.