I currently have a battery bank in my RV consisting of 2- 100 AHr 12v SOK batteries in parallel connected to a 12v/120v inverter/charger. I want to add capacity to it and the best option (size/price) would be to add a EG4 400 AHr 12v Server rack battery. Based on Will's EG4 tear-down videos it appear the EG4 12v, 24v and 48v server rack batteries are all made using the same number of same size cells in different configurations (12v/ 400 AH= 16 100 AH cells in parallel, 24/200 Ah = 8P2S, etc.) If this is the case it would seem placing a 12v/400 AH SR battery in parallel with the the two existing SOKs should create a 600 Ahr 12V bank. BUT - I was told by Singular Solar CS that I should instead replace the SOKs with 2 of the EG4s or add 4 SS 100AHr 12v batteries . Aside of increased capacity (800 vs 600 AH) why should mixing battery sizes as noted above make a difference as all are in parallel?