Pufflerman

Hey everyone this might be quite long so I thank you in advance. So I currently own a Honda cbr 125, it’s been a massive pain in my ass since I bought this new issue has stumped me. Another problem is I’m not exactly in the mood to take it to a mechanic as I’ve already sunk £1500 on fixing a bike I bought for £2400. I’m also planning on doing my a2 soon so another reason I don’t want to sink more money in. So the issue, my bike pretends like my battery is dead. Every few weeks the bike will just refuse to work (last few months) without a jump or taking the battery out for a charge in my house. However when I take the battery out and put it on charge it only take around 10 minute for my charger to say it is ready and maintaining. I also don’t think it’s a battery problem as when it refuses to start the battery is still giving it juice as the bike is attempting to turnover but just not being able to. Over Christmas luckily I had the entire family over, two bikers and a ex mechanic. They where both not sure but narrowed it down to either being the spark plugs or alternator(I think it’s called something different on a bike). However to me this still doesn’t sound logical as if it was spark plugs then why does the bike start up perfect after a charge, or why does the battery display ready and maintaining so quickly. Surely if the alternator was either over charging or under charging it wouldn’t work properly. I know that’s not going to be very easy to understand but if you have any questions please ask. Thanks guys