When you're selling online, you never see the device again after it ships. So the outcomes you care about are: does it work reliably, does it last through a reasonable number of charge cycles, and does it fail safely if something goes wrong. The most valuable outcome is a low rate of returns due to defects. A battery that swells, leaks, or stops charging after a few weeks will generate angry customer emails, negative reviews, and possibly chargebacks. That's the real cost of a poor safety design.

Another outcome that's easy to overlook is customer confidence. If a buyer has a good experience, they might come back for more products. If they have a bad one, they'll tell their friends and maybe post a review that you can't delete. So the right battery is part of your brand's reputation.

But not all safety features are equal. You might see terms like "overcharge protection" or "short circuit protection" on a spec sheet, but unless the manufacturer uses quality components and tests their devices, those protections might not work as promised. That's why you should look for products from brands that have been around for a while and have a track record of safe products.