Batteries in parallel

[Cycle Guy]

Hello,

I recently asked myself a question. What happens if I build a batteriepack with, let's say 10 Headway batteries, in parallel. All the batteries have different internal resistances. When I draw a current out of the batteries, there will be a different voltage drop at the different batteries. Because of that there will be a current between the batteries in parallel.

Now my question..Can I put the batteries without any other parts in parallel? Is there a mistake in my brainstorming i wrote above?

Thanks

Marco