thx for link
how did you pick 100/50 vs 100/30.
Hi xavpil - check out this link for sizing a charge controller:
Sizing MPPT Charge Controllers - DIY Renewable Energy Resources
The three, main things you need to be thinking about are:
1. The nominal voltage of the battery bank (probably 12V for you)
2. The input voltage to the controller (the voltage on the solar panel side) - depends on the solar panels you are using and the way you wire them (read about series vs. parallel wiring)
3. The max output amperage rating of the controller (depends on the overall wattage of your solar panel array)
Also - you need to think about how much current you can put into your batteries. If you are using LiFePO4 batteries, you can throw a lot of current into them. Traditional lead acid or AGM batteries are more sensitive.
PS - if you don't mind me asking, what is your first language?