RCU Forums - Starter recommendation for YS170DZ

Well, it turns my Magnum geared starter and 18V(5s) 3A lithium pack wouldn't cut the mustard for me on the weekend anymore, and I ended up borrowing 2 x 12V batteries connected in series to get the party started.

Stripped it down and cleaned up the commutator and switches, cut off the long wires and alligator clips and run some flying leads with Deans Ultra connectors and see if that helps.

Just for kicks with the mods, the oscilloscope says my starter current is 76A-80A (peak) and the pack voltage drops from 20.2V to 12.6V at the instant I hit the switch (stationary rotor) and takes about 1/4 sec to reach full rpm under no load.

Looks like the lithium-ion cells are struggling. A good 5s li-po pack should hold about 18V which would give about 112A (read about 40% more locked rotor torque).

More useless information....