If the charging system was bad, did you run the battery down until it would not start the bike, more than once? This is called 'deep discharge', and it kills lead-acid flooded cells, rather fast. Gel Cells, and AGM batteries are more forgiving, but deep discharging will kill any type of battery, if it takes enough hits.
Pull your battery, charge it with a smart charger, until it reaches float mode. Then pull it, and head down to an auto parts store. They can do a load test, for free, and tell you if it is good, or not.
If the battery is toast, buy an AGM, if you have the cash. If not, buy a flooded, lead-acid battery, and
carefully follow the instructions for preparing it for use (true for any type of battery -- same consequences) -- if you do not follow directions exactly, you will shorten the life of the battery (heat from the chemical reactions, and improper charging procedures, can damage the sponge lead plates within)...
If you don't already have a smart charger, get one. They can double the life of any battery
if you connect your bike after every ride... They will top off the charge, monitor, and maintain the battery between rides, and thereby prolong their life. It really makes a difference when you hit the starter after unplugging it: it will spin noticeably faster, due to a fully charged battery.
Consider installing a voltage meter/battery monitor: they can be had for around $6 for the voltmeter (type that plug into a cigarette lighter plug; other types available, but higher costs); will allow you to monitor the life/health of the battery, and the charging system, together, warning you of problems
before the bike leaves you sitting somewhere... Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII