>>2915558
>I think Paralleling a 15ah and a 50ah battery, both batteries would only max out at 15ah I think
You might want to learn baby-tier basics of electronics before messing with high current batteries. But rest assured, you're wrong about everything and there's no issue putting two batteries of the same voltage in parallel. However, they should be around the same state of charge when you connect them, i.e. if the 15Ah battery is discharged, then your 50Ah main battery should also be on the lower end. Obviously both batteries should have the same rated voltage, i.e. 4s/8/16s LFP batteries, do not combine different chemistries.