I usually only have issues with one of them. My st1100 battery will give me trouble if it sits too long...way more than 2 weeks though. May need more riding time :-). Or the battery could be at the end of its life cycle assuming your charging OK.
78 F250 Body, 73-75 Highboy Chassis w/390V8 NP435 NP205, D44-F D60-R.