They solve different backup problems
A portable power station is a self-contained appliance that can power plugged-in loads and may accept portable or fixed solar input within its ratings. A fixed home battery is integrated with building electrical systems through approved inverters, gateways, transfer equipment and protection. Portable equipment can be excellent for selected devices, but it should not be treated as a substitute for a code-compliant whole-home transfer system.
Transfer and circuit coverage are major differences
A fixed battery can automatically energize designated circuits during a grid outage when the system is designed for backup. Portable units usually require the user to connect individual loads, unless a manufacturer offers a specifically approved home-integration accessory installed to local electrical requirements. Improvised backfeeding through outlets is unsafe and should never be used.
Portability trades against installed integration
Portable systems are easier to move, can serve camping or temporary work and may avoid permanent construction. Fixed systems can offer larger scalable capacity, automatic solar coordination, utility programs and integrated monitoring. The cost comparison should include transfer equipment, electrical work and the number of loads that actually need backup.
Choose from an outage load list
List essential appliances, continuous and surge power, desired runtime and recharge options. If the goal is a refrigerator, router, lights and charging devices, a portable unit may be sufficient. If the goal is automatic backup of pumps, HVAC or many circuits, a properly engineered fixed system is usually the more appropriate architecture. Compare exact products rather than assuming every device in either category has the same capabilities.