Non-replacable or replacable batteries in detectors

[James]

I was looking at some manufactures of detectors an their batteries can not be replaced in the field. Batteries have improved over the years but on the off chance that your new detector an sealed battery kit goes dark while hunting , the detectorist is going to have a bad day. The U.S. manufactures have replaceable batteries holders and the overseas models seem to be permeant sealed state. Any thoughts why sealed batteries are be so promoted? Happy New Year to all Jim

[SVEN1]

Factory Sealed as the detector control box is probably waterproof. Improper dis-assembly and re-assembly could render the detector non-waterproof.
Would void any warranty?
And if replaced at a time of high humidity, may suffer internal condensation. Placing a small Silica gel pack inside would help in this regard to a point.
Lithium-ion and Li-poly batteries don't like water!

Sealed internal rechargeable detector batteries are similar to cellphone batteries which are much cheaper over the long term, than non-rechargeable, rechargeable Alkaline AA, 9 volt batteries.