2012 MacBook Pro Battery Replacement:

Visit an Authorized Apple Service Provider and ask them to replace the battery.

Even though the MacBook Pro 2012 is not official supported anymore, they know exactly which 3rd party spare part battery will work with your model.

If this is the 13" non-Retina model, then Apple may be able to replace the battery for you.

If Apple or an Apple Authorized Service Provider is no longer able to replace the battery for this particular model, then you can get a third party battery from OWC or iFixIt. Keep in mind the battery in the Retina model is glued to the underside of the palmrest & trackpad so it is a bit difficult to replace....there have been a lot of posts on these forums where a user accidentally damaged their laptop during the replacement. Also, the quality of third party Lithium batteries is extremely poor even when purchased from a reputable vendor. Third party batteries also need to be calibrated.

I replaced the battery in a 13" 2013 MBP about a year ago. The battery from DV Warehouse has been fine, though that isn't my primary computer anymore. I bought the computer from DV Warehouse in 2018 and it had no problems. The instructions on i fixit for the mid 2012 MBP look a lot easier than mine, as the battery has a hard case and is attached with screws, not glue, and there aren't any wires in the way.

Google is your friend.

Search: "replace mid-2012 MacBook Pro battery"

You'll find much good info, including vids.

replace the battery for service and update a new software for iphone 6s plus.

and diable all the content,crashes,link. and copy paste.