Well Googling this says a new battery is $99, or free with AppleCare. New phones are around $1000, so you do the math. I imagine if they damage the phone during replacement, that it would be their fault and they would need to replace the device. If you currently don't experience any battery issues I would ignore it until you start having issues with battery draining too fast. More on reddit.com

If you can afford the original, get one. However, I replaced mine with a ‘fake’ battery and it’s working fine. The only thing is you can’t check battery health like you can with an Apple battery. The warning goes way after a few charges/days, I forget now. My battery, with 7hrs of screen time, will last all day on my days off. I’m in school and work, and often need to look things up, plus I use my phone during breaks. Those days, I can go home with a 40-60% charge. Also, being made in China doesn’t really mean anything in terms of quality. Everything is made in China these days, or just about everything. However, they are made to the product owners specifications. They can be made slowly, with high quality materials and quality tested. Or, they can be made quickly, with cheaper materials and not tested at all. Look at who owns the original product patent and what country they are located in. That can help determine the profit percentage they might charge, and therefor if they ordered a quality product to be made or a cheap on with higher profits for themselves. Examples there would be Walmart toasters or Doctor Martens boots. Both made in China, both now terrible quality, but Walmart is based in USA and the Walton family is absolutely gouging in profit margins. They are choosing to make a cheap, low quality item that probably costs them $3 and they sell it for $20. China isn’t making a cheap toaster because China makes cheap things. China is making a cheap toaster because Walmart doesn’t want to pay for an expensive toaster. A lot of Chinese companies are realising this, are making good and great quality products and selling them under their own names without the huge profit margins that foreign companies charge. If you look around and read reviews etc, you can find some excellent deals. More on reddit.com

I had mine replaced on my 13 mini earlier this year. Took it to an Apple store (made an appointment). Took about an hour and a half More on reddit.com

Do NOT listen to these fools telling you you need to find a 3rd party replacement for the battery. It should only cost you ~$89 to have Apple themselves replace it for you. If ANYthing goes wrong, something gets damaged, or doesn’t work, Apple will fix it for you at no charge. If you cheap out and bring it to a 3rd party repair shop or even try to replace it yourself, something could go wrong or break as the parts in phones are extremely small. Then you’ll end up paying even more to fix mistakes. Just make an appointment at an Apple Store and have them do it for a bit less than $100. You get full battery as well as the peace of mind knowing that if something does go wrong, Apple will make it right. More on reddit.com