With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
If you add a 3,5mm jack to those small earbuds, there definitely won’t be any space for a battery. It’s one or the other.
I think he meant having the 3,5 mm jack in a phone.
The buds don’t need a jack. Just the lead that connects to the phone or whatever. That takes no real space.
Just to be pedantic; a battery is significantly larger than 2 tiny wires of copper. The battery is almost 50% of the volume in the earbud.
I’d give up the space of a battery for a jack, yes