How many batteries should I buy?!? Do I need spares?

So I’m about to buy my samsung 30qs and I’m worried that perhaps I may get some duds.

I’m planning on doing a 10s4p so I need 40 cells for it to work, but should I order a few extra? I’m planning on ordering from and want to order these but I feel nervous about just ordering exactly 40 just in case!

So when you all build your batteries, do you order extras? If so, how many?

Thanks everyone!

LiionWholesale are pretty reputable so doubtful you will get duds, that being said always err on the side of caution because you never know if some may break during assembly or even when the pack is finished and under load…you just never know.

My advice to you would be to get anywhere between 3-10 extra (Or whatever is within your budget) and then if needed you wont need to pay heaps for shipping a couple of cells and if not you can always sell at a gain to others like the vaping community or whatever.

Keep in mind depending on the amount you get some sellers give discounts as well! Happy building!

Thanks for the quick reply!

I’m also looking at just buying a prebuilt battery…any good ones out there that are trusted?