An Option 61 could be in several configurations and multiple columns. Hard to tell what you have. The key to this is the amp hours on the battery and how long you want to hold the system up. You need to come up with 48 volts in any combination you want, 4 12 volt batteries, 8 6 bolt batteries or any combination you want but it needs to equal 48 volts. Have you looked at the batteries to see if they are 12 or 6 volt?