Cap charging power

Charging power is a setting, not a command: write max_charge_rate once and the charger keeps it across sessions until you change it. See Settings for how settings differ from commands.

1. Check the device supports it

curl https://api.amps.ai/ev-charger/device_abc123 \
  -H "x-api-key: $AMPS_API_KEY"

{
  "success": true,
  "data": {
    "id": "device_abc123",
    "state": { "status": "charging", "currentPower": 11, "powerRateLimit": 11 },
    "settings": {
      "max_charge_rate": { "value": 11, "unit": "kw", "min": 0, "max": 50, "step": 0.1 },
      "max_charge_current": { "value": 32, "unit": "amps", "min": 6, "max": 32, "step": 1 }
    }
  }
}

If settings.max_charge_rate is missing, the charger doesn’t expose a power cap in kW. Stay inside its min and max, on a multiple of step.

2. Write the setting

Send only the settings you want to change.

curl -X POST https://api.amps.ai/ev-charger/device_abc123/settings \
  -H "x-api-key: $AMPS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "max_charge_rate": { "value": 7.4, "unit": "kw" } }'

{
  "success": true,
  "data": {
    "deviceId": "device_abc123",
    "updated": ["max_charge_rate"]
  }
}

Settings return 200, not 202, and don’t create an action. A value outside the bounds or off the step grid returns 422 SETTING_OUT_OF_RANGE. max_charge_rate and max_charge_current are the same cap in two units: send one, or you get 422 UNSUPPORTED_SETTING_COMBINATION.

3. Confirm

Read the device again: settings.max_charge_rate.value shows 7.4. See Pull for how fresh a read is. To cap a single session instead, send power or current on the charge command. See Start and stop a session.

Cap for a grid event, then restore

A grid operator may require a lower limit for a few hours, such as 4.2 kW. Amps keeps no record of the previous value, so save settings.max_charge_rate.value before you write the cap, and write it back when the event ends.

# Event starts: you saved 11 from the read in step 1
curl -X POST https://api.amps.ai/ev-charger/device_abc123/settings \
  -H "x-api-key: $AMPS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "max_charge_rate": { "value": 4.2, "unit": "kw" } }'

# Event ends: restore the saved value
curl -X POST https://api.amps.ai/ev-charger/device_abc123/settings \
  -H "x-api-key: $AMPS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "max_charge_rate": { "value": 11, "unit": "kw" } }'

The cap also applies to sessions that start during the event. Some cars only slow down after a pause in the session, so if the limit is a hard obligation, push idle for the event instead. The restore overwrites any change someone else made meanwhile: read the device first if that matters.

Get started

API Reference

Guides

Cookbooks

1. Check the device supports it

2. Write the setting

3. Confirm

Cap for a grid event, then restore

Next steps

Start and stop a session

Settings

​1. Check the device supports it

​2. Write the setting

​3. Confirm

​Cap for a grid event, then restore

​Next steps

Start and stop a session

Settings

1. Check the device supports it

2. Write the setting

3. Confirm

Cap for a grid event, then restore

Next steps