This charger does charge with no problem but does not maintain.  I am a huge Schumacher fan.  But this time you get what you pay for.  First off This charger is inconsistent.  I measured the final voltage before charging stops.  It ranged from 14.77bed to 16.40vdc that's not good.  My biggest complaint is that once charging stops It never starts again.  I discharged my battery down to 6vdc to check when the maintainer would start the charging cycle again and it never did.  Super not cool if you want to leave your battery pluged in for long term or winter storage.  However I am going to use this charger, my needs are pluging in my truck every night for battery charger and engine heater.  So for me this works perfectly.  I have a warm engine every morning and a battery bank topped off in my truck I use for camping with an inverter and a huge battery bank that is wired into my trucks electrical system.  I plug it in every night and it reaches it's top off voltage and shuts down and my engine block heater keeps going and that works for me.  So do not buy this for a camper or anything you plan to store and not use for more than a couple of weeks or as an alternative for a vehicle with an electrical ground you cannot find that slowly drains your battery because it will be dead when you go to start it 2 weeks later.  Buy a better charger.  I have a schumacher 12vdc atm standard battery charger that works for anything you need.  But much more expensive.  You can find alternative cheap battery maintainers.  Just do your research before you make a long term commitment battery charger.  Good luck.