I recently replaced my old wet cell battery bank with a new 200 Ahr 12v SOK bank (2- 100 AHr batteries). Recently will published a Youtube on a cheap DIY-build he made using 280 AHr cells for around $200. I believe they were B grade and likely only about 80% of stated capacity, but I was thinking if I can add another 200-240 ahrs for that kind of money (plus a BMS) it would be worth while. Question though is are there problems with this kind of addition as long as the voltage (12v) and battery chemistry remains the same?