do you want a float charger or something with high current? Why not just go to costco or northern tool and buy one? are you looking to build lots of just one for a specific application? I have one I bought from costco and it cost me maybe 40 bucks.. it has a float mode - automatic and it has a 50 amp starting boost too.. i have used it several times
The Linear Technology LT3652 is a battery charger IC that is suitable for 12V sealed lead acid applications. I used this chip on a PCB I recently designed and found it very easy to use.
"LT3652 article with schematic":http://cds.linear.com/docs/Article/PET_EN_092009.pdf
