My 14 months 50Ah battery gets discharged in two weeks. The parasitic current is 15-40mA (0.04A). Is this excessive? A third is for alarm, third for clock, third I could not identify. Radio is already isolated. Battery is 12.6V, voltage when idle run 14.0, with lights, fan and heating on 13.9, so alternator is probably OK. Any ideas please?