Gel Battery Chargers An Excellent Book On Solar Power Battery Chargers?

Battery Chargers? - gel battery chargers an excellent book on solar power

Chargers: What is the difference between a battery charger to the freezing acid battery and a charger.
I say this because I have a scooter, if you do not recharge the battery with my charger that came with the bike batteries seem to last have.
I have two acid batteries, but they seem to have difficulty
Is there a difference between acid and gel battery