101 questions ill start with 4 or 5

[rickhise]

found these 2 panels in the building, 1st. panal, max power 51 watts, max power volts 16.9V, max current 3.02 amps, 2nd panel 80 watts, 22 volts 5.1 amps...

goal is to put back some battery charge back into my battery bank (of 8 agm's 6 volt 100 amps batts).. Question can I hook the 2 panels together pos to pos., neg to neg, At this point I dont have a regulator. My battery bank of 8 AGM's 6 volt, 100 amp each battery, connected to give me a 12 volt output, is being used to run a few household items frig, lights fan wall chargers, hoping to begin using the solar panel to put a small amount of charge back into the batts, the panels are free, and why not?

I have a back up gen to start when i have to to build the bank back up, so I thought no more than we draw from ther bank I would start off as basic as I can and build on as I learn an go from persons like you on this site thanks

I will have pulled the bank down and not too concerned if any about over charge..... So if over charge isnt an issue do I need a regulator
Ill see what I learn from the above question before I go further thanks for your time

[Sunking]

Well without a MPPT controller, or PWM controller when you connect the two panels in parallel will only give 3 amps + 5 amps = 8 amps of charge current (about 90 to 100 watts). Connect them in series and all you will get is 3 amps or 35 watts. Adding a PWM controller will only make things worse with lower power. Use an MPPT controller with the panels in parallel and you will get roughly 10 amps to the battery or about 120 watts.

With that said there is no way this system can support a 12 volt 400 AH battery. It will barely keep up just using 2 of your batteries at 12 volt 100 AH.