> ## Documentation Index
> Fetch the complete documentation index at: https://docs.voltview.co.uk/llms.txt
> Use this file to discover all available pages before exploring further.

# Batteries

> Read state of charge and charge/discharge power. After solar.

Batteries follow solar. Same rule: VoltView reads the inverter or battery portal. We do not dispatch the battery in v1.

A battery in VoltView is one storage system on one site, mapped to the same site and import MPAN as the solar it sits with (if any).

## When this ships

After the solar connect-and-map path is live on at least one OEM. Do not promise battery data on a site until that path exists.

## What you get

| Series                                    | Unit | Source                                                                |
| ----------------------------------------- | ---- | --------------------------------------------------------------------- |
| State of charge                           | %    | Battery / hybrid inverter portal                                      |
| Energy remaining                          | kWh  | Derived from usable capacity × SOC, or from the portal if it sends it |
| Charge power                              | kW   | Portal (positive into the battery)                                    |
| Discharge power                           | kW   | Portal (positive out of the battery)                                  |
| Charge / discharge energy in the interval | kWh  | Portal                                                                |
| Status                                    | enum | Online, charging, discharging, idle, fault                            |

With solar and the import meter on the same site, VoltView can then show whether the battery charged from solar, from the grid, or covered a peak that would otherwise have been imported. "Covered a peak" means the battery discharged in the same settlement interval as the [maximum demand](/metering/demand) — usually a half-hour.

Those splits are derived. They need all three feeds (solar, battery, meter) on the same interval.

## Connect

Same preference order as solar:

1. OEM API token.
2. Read-only portal user.
3. Installer share.
4. File export (not a live feed).

Hybrid inverters often expose PV and battery on the **same** portal. In that case one connection can populate both a solar system and a battery on the site. Still store them as two assets so the meter mapping stays explicit.

## Map to the site

| Field                | Required   | Notes                             |
| -------------------- | ---------- | --------------------------------- |
| Site                 | Yes        | Existing VoltView site            |
| Import MPAN          | Yes        | The meter the battery can offset  |
| Usable capacity      | Yes        | kWh, not nameplate if they differ |
| Coupled solar system | If present | Link to the VoltView solar asset  |
| Portal / OEM         | Yes        | Which connector to use            |

## Ownership

Same test as solar. If a funder owns the battery, their portal is the one that matters. Many UK C\&I PPA roofs have **no storage**. Do not create a battery asset because the customer is "interested in batteries."

## Supported after solar

No battery connector is in v1 until solar is shipping. The first targets are the portals we will already be in for PV:

| Portal                           | Notes                                             |
| -------------------------------- | ------------------------------------------------- |
| SolarEdge Energy Bank / storedge | Same monitoring login as the PV                   |
| SMA / Sungrow / Fronius hybrid   | Same as the PV portal where the site is hybrid    |
| GivEnergy, FoxESS                | Common UK storage; add when a live site uses them |

Residential products (for example Powerwall on a house) are not the C\&I default. Add them only for a real site.

## What we do not do yet

* Charge, discharge, or change a backup reserve.
* Tariff-based optimisation on the battery.
* Flexibility / VPP enrolment.
* Sizing or payback as a live control loop. Modelling stays in the account conversation, not in the asset API.

## Checks after first pull

1. Usable kWh matches the commissioning sheet.
2. SOC stays in 0–100 and moves when charge/discharge power is non-zero.
3. Interval energy is consistent with average power over the interval.
4. If linked solar exists, battery charge in daylight is not treated as grid charge without looking at generation.