These GTF batteries are showing up more and more across Ebay and other websites that sell Chinese stuff.
https://www.aliexpress.com/item/2017-30PCS-set-Brand-New-18650-battery-3-7V-9900mAh-rechargeable-li-ion-battery-for-Led/32796342249.html?src=google&albslr=230206914&src=google&albch=shopping&acnt=494-037-6276&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&gclsrc=aw.ds&&albagn=888888&albcp=1706973087&albag=65008162765&trgt=296904914040&crea=en32796342249&netw=u&device=t&gclid=CjwKCAjw4LfkBRBDEiwAc2DSlJohz93NuG2UJeKNjE5Zu0vDm0cQXLe_Une5-GjJro0ehvBUunpAvRoCUK8QAvD_BwE
Good points.
Each cell weighs only half what a normal 18650 weighs, so a 40 cell battery will weigh about 1kg.
10 cells cost £8.92 with free shipping.
They're a nice colour if you like red.
They're marked "short circuit and over-current protection", which is very reassuring.
They make good stink bombs if you cut them open.
Bad points
Actual capacity is closer to 700mAh, so your 39.6Ah shrinks to 2.8Ah before you start.
They're not very consistent, so the probability of catching fire is very high and you'll need a very good BMS to keep them balanced.
There isn't a protection system in them.
Sorry to get your hopes up and then dash them down. My only excuse is it's Sunday afternoon and I'm bored. I can think of a meaning for GTF, which is what everyone should shout when they see these batteries. I don’t know how these sellers get away with it.
https://www.aliexpress.com/item/2017-30PCS-set-Brand-New-18650-battery-3-7V-9900mAh-rechargeable-li-ion-battery-for-Led/32796342249.html?src=google&albslr=230206914&src=google&albch=shopping&acnt=494-037-6276&isdl=y&slnk=&plac=&mtctp=&albbt=Google_7_shopping&aff_platform=google&aff_short_key=UneMJZVf&gclsrc=aw.ds&&albagn=888888&albcp=1706973087&albag=65008162765&trgt=296904914040&crea=en32796342249&netw=u&device=t&gclid=CjwKCAjw4LfkBRBDEiwAc2DSlJohz93NuG2UJeKNjE5Zu0vDm0cQXLe_Une5-GjJro0ehvBUunpAvRoCUK8QAvD_BwE
Good points.
Each cell weighs only half what a normal 18650 weighs, so a 40 cell battery will weigh about 1kg.
10 cells cost £8.92 with free shipping.
They're a nice colour if you like red.
They're marked "short circuit and over-current protection", which is very reassuring.
They make good stink bombs if you cut them open.
Bad points
Actual capacity is closer to 700mAh, so your 39.6Ah shrinks to 2.8Ah before you start.
They're not very consistent, so the probability of catching fire is very high and you'll need a very good BMS to keep them balanced.
There isn't a protection system in them.
Sorry to get your hopes up and then dash them down. My only excuse is it's Sunday afternoon and I'm bored. I can think of a meaning for GTF, which is what everyone should shout when they see these batteries. I don’t know how these sellers get away with it.