{
  "entityType": "category",
  "id": "expansion-batteries",
  "canonicalUrl": "https://agentretrievalindex.com/categories/expansion-batteries/",
  "jsonUrl": "https://agentretrievalindex.com/categories/expansion-batteries.json",
  "name": "Expansion Batteries",
  "summary": "US-market add-on expansion batteries indexed from official manufacturer sources only. Each one enlarges a specific host power station, so host compatibility is the defining field and is recorded verbatim from the manufacturer, never inferred from a connector, a shared brand or a similar capacity. Capacity is always this unit's own rated energy, never a combined station-plus-expansion system total.",
  "intro": "This category covers add-on batteries that increase the capacity of a specific host power station, one entity per officially named model. It is deliberately separate from deep-cycle batteries. A deep-cycle battery is generic storage: the buyer supplies a charge controller and an inverter and builds a system around it, and its honest figures are its capacity, its charge and discharge envelope and its cycle life. An expansion battery is bound to a host line: it plugs into one manufacturer's power station, adds capacity to that station, and usually has no inverter and no output ports of its own, so the question that decides whether it is any use at all is which hosts the manufacturer names. That is why the schema makes the official compatibility statement a required field and records it verbatim. A matching connector, a shared brand or a similar capacity are never treated as a compatibility claim, because attaching an expansion battery to a host it was not built for can damage equipment, and this is the safety-critical rule of the family the way the outdoor-only carbon-monoxide gate is for generators. Two further anti-hype rules are enforced. Capacity is always this unit's own rated energy in watt-hours, never the combined system total the marketing leads with, because a headline like 'up to 25 kWh' describes a host plus several expansions rather than the component on the page. And an expansion battery is not a power supply: a claim that it has its own outlets must name the ports, since most have none. Expansion batteries sit beside battery power stations, deep-cycle batteries, solar panels, RV solar kits and generators as the capacity layer of a system a buyer has usually already chosen.",
  "attributes": [
    {
      "key": "official_compatibility_statement",
      "label": "Official compatibility statement",
      "description": "Verbatim manufacturer statement of which host power stations this battery works with. Never inferred. The defining and safety-critical field of this family."
    },
    {
      "key": "compatible_host_models",
      "label": "Compatible host models",
      "description": "The exact host model names the manufacturer names, as they name them."
    },
    {
      "key": "capacity_wh",
      "label": "Rated energy",
      "unit": "Wh",
      "description": "This expansion unit's own rated energy, never a combined host-plus-expansion system total."
    },
    {
      "key": "chemistry",
      "label": "Chemistry",
      "description": "lifepo4, lithium_ion_other, agm, gel, or flooded_lead_acid."
    },
    {
      "key": "max_chainable",
      "label": "Expansion units supported",
      "description": "How many expansion units the host officially supports, where stated."
    },
    {
      "key": "has_own_outlets",
      "label": "Own outlets",
      "description": "Whether the expansion unit itself exposes any AC, DC or USB ports. Most do not; a true value names the ports."
    },
    {
      "key": "charging_inputs",
      "label": "Direct charging inputs",
      "description": "Whether the unit can be charged directly by AC or solar, and at what rating, where stated."
    },
    {
      "key": "cycle_life",
      "label": "Cycle life",
      "description": "Rated cycles, recorded only with the depth of discharge it is quoted at."
    },
    {
      "key": "temperature_ranges",
      "label": "Temperature limits",
      "description": "Charge, discharge and storage temperature ranges where published."
    },
    {
      "key": "weight_kg",
      "label": "Weight",
      "unit": "kg"
    },
    {
      "key": "warranty_years",
      "label": "Warranty",
      "unit": "years"
    }
  ],
  "products": [],
  "comparisons": [],
  "updatedAt": "2026-08-15"
}