Hi, i have some rechargable batteries that currently make 11.1V in series i wanna make it 18V ish but there is a blue and white wire that goes between each battery. I'm not sure what they do. the part that would normally go the the device is just the red and black the extra wires are for the charging.

Can anyone tell me what these blue and white cables do?

and If i were to attach 2 extra batteries on the end with what would happen?

 

The extra wires are there in order to charge individual cells.

 

So would it be bad to remove all those individual cell charging wires and just charge it from on end to the other?

 

It's for battery balancing during charging, you can add extra cells to make it upto 18V , but you need a 5 cell balancing PCB ideally for charging.