Nah mate dont need no charger either, if your battery just lets say "sh!t itself" you can get brand new batteries on ebay for 30$... but the chances of that happening are almost non existent
I agree with you that two weeks is a none issue. if it was a deep cycle battery or a Lithium Ion in the bike I wouldn't ever worry - but its not. So if its gunna sit for more than 2 weeks its much easer to keep it charged then have to order one on-line wait for it then install it, save on the environment too my good man..!
The cheap batteries in our bikes are designed to always be fully charged, if you let them sit and discharge - then you will loose total battery capacity ( Cold Cranking Amp ) in a relatively short time period, and no matter how much you ride your bike they will never fully recharge. I get it, there cheap but bad for the environment when you toss them in the trash cause I'm pretty sure your not going to be diligent and recycle them, this goes for me too..!
Right now its a huge problem in the world, we buy and make everything cheap, its service life is short and we just throw it away, unfortunately with batteries we are creating toxic wastelands when we just throw them away and not recycle them.
Just a thought.