Scooter Batteries: Can you wire 4 in series and 1 in parallel?

I'm selling my electric scooter to a neighbor who trashed his own. It's a virtually identical model aside from mine being a year older than his. he says his scooter runs on 5 batteries. Looking up the scooter parts info states, the control board and motor run off 48v. When I popped my scooter battery compartment lid open, I saw 4 12v batteries wired in series. So that's where the 48v comes from. Soooo could is be possible that the scooter batteries on the neighbors scooter are wired in 4 batteries in series to get 48v and one battery in parallel to add a bit off current to the total? 

rickharris1 month ago

Dont know we would need to see a circuit diagram to be able to make a guess.

It would be VERY unusual to have 4 12 volt batteries in series then one in parallel across them all - No point.

Is the extra battery for lights or something.