I have a 5s lipo that I bought a few months ago but haven't had much time to run with it. I was going to cycle it the other day and my charger kept yelling at me saying I've connected a 4s battery. I checked it with a digital volt meter on my Hobbywing program card and sure enough cell 3 is completely dead. All cells show 3.94 except cell 3 which is 0. No puffing of any kind so I thought maybe a wire came off. From what I can tell that's not the case.

So I'd like to be certain the cell is dead and that I don't have a bad solder joint and secondary want to create a 4s pack or 2 2s packs.

How would I go about doing so?

Thanks