I have a simple Solar setup, using MPPT 75 I 15, a Siemens Solar Panel M110-24 and a 12V110Ah battery. 
I want to add more battery capacity, and I'll buy a new battery, like 12V200Ah, but it'll be different from age and capacity, I was wondering if it's advised to connect them in parallel (same length cable size)? 
if not, what's your advise? thanks in advance,best regards.
Yea, but you willuse the 110 more then the 200 wire it asynchron... (-) from the mppt to the 200 and the (+) to the 110
hi, thanks for reply, as I understood, the 110Ah battery will discharge first than 200Ah battery? even when they are in parallel? in that case, adding a parallel battery will not increase the bank capacity? I'm confused. Will the use of Argo FET 100-2 do the job? thanks.
hi, thanks for reply, as I understood, the 110Ah battery will discharge first than 200Ah battery? even when they are in parallel? in that case, adding a parallel battery will not increase the bank capacity? will the use of Argo FET 100-2 do the job?
I re-draw the wiring you advised; should be like this?
