battery manufacture date

[N.T. Diluvian]

I'm new to the forum, and new to e-bikes, so thanks in advance for humouring me ...

Last November (2020) I bought a Daymak e-bike online from costco.ca here in Toronto. It's this one: https://www.daymak.com/milan

When I unpacked it I saw a label on the battery that looks like it might be a date stamp. A pic is attached. To my untrained eyes it looks like "DE 2009" may refer to the date the battery was manufactured. If this is correct then the battery is more than eleven years old. (There's a bunch of other text on the label but I can't decipher what it means)

I raised this issue with Costco who told me that Daytek insists the battery was manufactured in 2019, not 2009. Who/what should I believe?

(I understand that a Lithium-Ion battery like this one will lose significant charging capacity over the years even if it isn't used. Am I right about that?)

 

[Dallant]

I seriously doubt it was built a decade ago but I suppose it’s possible. What’s the warranty like? Do you have direct phone or web access to the manufacturer? If so I would contact them directly. Actually, it looks like you have a local Daymak store and I would call them about it.
Toronto North Ebikeuniverse - 134 Oakdale Rd. Toronto, ON M3N 1V9 TEL: 416-744-2453
That may or may not be the manufacture date but this is why buying without professional support is a bit of a crap shoot. Best of luck.