I've read other similar posts laying blame for hard starting, and poor engine performance on electrical issues. Perhaps the fuel injection system in our Hondas, which is controlled by a mini-computer, is very sensitive to battery voltage.
The standard OEM battery is small and probably has a modest storage capacity. If your Honda is not connected to a battery maintainer when not in use the battery is slowly dying.
I use and recommend one of hese:
Buy Battery Tender 4 Amp, 6V or 12V Selectable Battery Charger, New at Walmart.com
www.walmart.com
There are dozens of brands offered but the "Battery Tender" brand uses a four-stage charge and maintain cycle to maintain but never overcharge a battery.
I have several of them and have used them for years with good results.