charging system nfg ; battery takes charge but dies after riding

[Jo Rhett]

So I replaced the battery in my street bike about 5 months ago.  It's died on me three times in the last 2 weeks.  After doing some careful testing it's clear what's happening -- I can put it on a battery tender and get 4-5 (errand/trip) rides from it, but the battery is dead after that.  But it does accept a charge and does run quite well.

I think that the charging system is screwed, rather than the battery being already dead. Am I wrong? What should I replace?

-- 
Jo Rhett /  velociRaptor Racing
#553 WERA