Looking how to build our battery pack, I’ve started with 18650 cell as recommended by Andrew. Then Andrew told me about 21700 and that there are others…. and I’ve got lost. What actually 18650 stands for, how about 21700?
So I started with Google and it came with this very nice picture.
Seeing it I instantly thought, let’s write a nice article on how they differentiate and then thought how many battery standards are around? Asking Google again it came with 18650, 20700, 21700 and 26650 … and I’ve completely lost it, because there is a Wikipedia page on Battery sizes and it goes for pages.
So back to our story, I’ve decided to buy a pack of “21700 Lithium Batteries 4800mah Li-ion Industrial Flat Top x 4” batteries from a local supplier.
A pack of 4 batteries arrived next day so I went eagerly to meet with Richard to test it!
Risa kept torturing (continuous 1C discharge test) the battery for hours and came with quite significant difference to what they state to be! Batteries are sold as 4800mah, but Risa clearly found out that they are only 4000 mah.
Even more test runs couldn’t come with undeniable fact that they are indeed 4000mah and not 4800mah.
Crazy times – I’ll keep you updated.