Small Engines (Lawn Mowers, etc.): John Deere 265 electrical problem, john deere battery

Question
I have a 1992 JD 265 M00265A1323??? label is damaged has a Kawasaki K series 17hp code FC540VDS00  E/NO FC540V186330.

I installed a new interstate megatron battery 3 weeks ago. I mowed the lawn twice with no problems. Today it started fine then died. Turning the key produced nothing not even lights, so I jumped it with my truck. It started right away but as soon as I switched on the lights or PTO it died. I jumped it again and as soon as I removed the jumper cables it died. What's going on. I appreciate any help. thanks

Answer
Charge the battery fully first.  Then check the voltage with the battery hooked up in the tractor and the key off.  Then start the engine and check the voltage again.  There should be a jump of 1-2 volts.  Let me know what you get from this.  Thanks, PK.