Batteries in Series vs Parallel

What does is mean to connect multiple batteries in parallel or in series? It's a simple distinction but it's very, very important to get it right if you've going to connect multiple batteries.

[@user10cool]

“grunt” = mAh

[@ProjectReaper]

Great video. Really made this easy to understand.

[@davidfarmer2049]

Quiz haha. I have to remind my self each time I come back to this.

[@hulerus4599]

What if i put batteries in paraller but they have diffrent voltages like 1.5V and 3V?

[@davidfarmer2049]

Hulerus,
I t would seem a wrong thing to do, so you don't.

[@davidfarmer2049]

@2,4..... gives out put duration. I think that's the way id put it.

[@busmemorija]

usefull, thanks!
i need your advice about connecting 18650 cells in parallel for my hoverboard. can i contact you on email? thanks!