Write-up doesn’t say whether or not, but pictures make it look like this massager might have a removable/replaceable battery, similar to the one I have.
I consider that an advantage:
(1) if battery goes bad, you don’t have to trash the whole device, if you can get a replacement battery;
(2) on mine, the recharge cord plugs directly into the battery, so you have a choice of recharging while the battery is installed or while the battery is removed (and easier to handle, or even while you are traveling with it);
(3) you can keep a spare battery charged.
I will admit, after a very quick search, I didn’t find any separate batteries for sale, but think they should exist (they are a commodity, after all).