cat 226b kills battery when switched off

my cat 226b skid steer kills the battery if you don't disconnect the battery lead. The charge light flickers abnormally when the key is pulled out from the ignition. i haven't checked anything much. also does my model machine carry 2 speed?

226B did NOT have a 2 speed travel option.
As for the battery issue, I suspect the alternator.

Unhook the alternator wires when it is shutoff . See if it still goes dead.

A Clamp on meter and voltmeter can go a long way at figuring out what is stealing the power. If no heavy duty mechanics are available some good automotive Techs. can figure out simple stuff like that. But sometimes it is more complicated. A multimeter put in series with the ground cable and the negative post of the battery can go a long ways at finding parasitic draws. Lots of good videos on You Tube to demonstrate how to find. But as heymccall posted could be the alternator.
Simon C