The camping hair dryer I have can pull up to 5A.....
The best investment I made re chargers was the electronic triple stage charger "Battery Fighter" Model BFA-012-230 (
www.batteryfighter.com)
I use this all the time to keep my collection of 20Ah gel cell batteries up to scratch. I haven't "lost" a battery since using it ( over two years now)
Highly recommended.