Motorcycle Repair: 1982 Honda CM450E Battery Dead?, 1982 honda cm450e, motorcycle batteries

Question
QUESTION: Yikes! I take the bike three miles to the grocery store for gallon of milk and back,and all is fine. But I forgot to turn the key off in my driveway. Under an hour later, I go out to ride 1 mile to the post office, and discover the bike is dead: No lights, no sound, no crank. Dead.
Fortunately I push start it down a hill and ride easily to the post office (1 mile) but the bike is dead when I come out.  I push start again, and ride 5 miles to Lowes, just to charge the battery up again. After 10 minutes, Lowes is closing, and my bike is DEAD AGAIN.  
I push started it with difficulty and rode home about 3 miles, but parked it in the garage this time.  
DO I NEED TO PUT THE BATTERY ON A BATTERY CHARGER OVERNIGHT? (just connect the leads with the battery still on the bike?)  How risky is this? I'm told this battery was less than 2 years old, and it normally starts the bike without problem within 3 seconds of cranking.  THanks!

ANSWER: You can't charge a motorcycle battery by riding it.  It works for cars because car batteries can absorb a lot of current and the alternators put out a lot of current.  Motorcycle batteries are supposed to be charged at 2 amps to prevent overheating.  It takes 8-12 hours to fully charge a battery at 2 amps.  So unless you need to ride around for 8 hours, I'd recommend putting a charger on it.  There's not a lot of reserve in those small batteries so this sounds pretty normal.

Regards
Rich

---------- FOLLOW-UP ----------

QUESTION: After taking the bike to a Honda dealer,I described the problem and how I had charged it for two hours at 6 amps, and then overnight at 2 amps, and all was fine. However, the tech immediately recognised that the battery was installed incorrectly, with the vent tube flapping in the wind and the redcap still on, blocking the vent. He warned that I had been risking explosion or at least the cell caps popping... which one did after the first hour!

Answer
Yea, I'm glad you got that straightened out.  When you charge a battery, hydrogen gas is released.  It can build up and pop the caps out like you found out.  I've never heard of a battery exploding because of this but I have heard them explode due to a internal short or spark that ignites the fumes when some one was hooking up jumper cables or a battery charger.

Regards
Rich