I cant quite make out what all of the numerals on  your picture of the MFD.  Fortson, if I understand you correctly your amps are showing -.5 amp discharge, after you leave planet earth, and have no change in draw with additional load.  This does not seem correct to me, as you should be at the same 0 as just before take-off.  Your battery is probably nearly or completly recharged by the time you taxi to the end of the runway.  I dont have a wiring diagram, but would be willing to suspect that there might be something wired into a weight on wheels switch, but that also seems unlikely, since you didnt indicate that your plane had a retractable gear.  I would begin to look at the voltage regulator, and your alternator, and all associated connections and verify that they are tight.  If you can try to note the instant that the amp starts to draw negitive or go + charging (ie. during rotation, while landing, ect...).  If you can isolate the systems and notate the time that it occurs it will help your mechanic, and should save you $$ in unnecessary troubleshooting.