Can't find a new Wiko Wax battery
I would like to buy a spare battery for my smartphone. The phone is a Wiko Wax, and I know that the Wiko brand is not very famous worldwide, but it is in western Europe. It's a French/Chinese brand and their products are manufactured in China.
I'm unable to find an internal battery for this specific model online, on websites like eBay but I can easily find some for other models released at the same time. I actually found a battery but the price was way too high (€30, which is the price of an external power bank that would allow me to recharge the phone 4 times). As a comparison, I'm seeing batteries for Samsung S4's at just €10.
So I'd like to know where I can online retailers (in China for example) who have this battery. Otherwise I think that I might be able to use batteries designed for other models but I would like to know how I can know if they are compatible or not.