The phrase "attached battery" is correct and usable in written English.
It can be used to describe a battery that is physically connected to a device or system, often in the context of electronics or portable devices.
Example: "The smartphone features an attached battery that provides up to 24 hours of usage on a single charge."
Alternatives: "integrated battery" or "built-in battery".
As you pedal away, the generator is charging the attached battery.
The attached battery pack can be worn over the shoulder and has hand controls for adjusting to different lighting and settings.
The product is controlled by voice or via a small touchpad on the right arm of the device; can be connected to the internet via a tethered phone; and lasts for about six hours thanks to an attached battery - although the All Things D site reports that Google intends to extend that to a day.
This saw is a direct drive (sidewinder) type but uses an attached battery, like the cordless drill, to power it.
These nodes are typically powered by attached batteries.
Bioelectronic remedies attach battery-powered implants the size of a grain of rice or smaller to individual nerves to correct faulty electrical signals between the nervous system and the body's organs.
Carry a portable battery to the spot and attach battery-operated fairy lights to the surrounding trees and bushes or lay the lights in a giant circle around the party area on the beach for a truly magical effect.
Many of those cords are attached to battery packs, but there are a sizable number of other cables.
Researchers at the Public Laboratory for Open Technology and Science (PLOTS), in conjunction with the Rhode Island School of Design, attached a battery pack (in black, above), circuit boards, and a chemical sensor (next to the light) to a floor-cleaning Roomba robot.
Once attached, the battery works with the internal cell to provide you with extra power.
Plus, it has an attached ejectable battery that every writer needs.
