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Hybrid co-locatedUnited StatesEIR-1315

Home battery reported drained by EV charger during a grid outage

2026Published 25 Sept 2026Responsible editor: Chief Editor

MinorControl systemProvisional
Estimated damageEstimated by the register's adjusterHow? Know the real figure?
Figure hidden: shown to subscribersMedium confidence
out of service for about •• daysShown in the record →Full estimate
From the recordRoot cause hiddenFailed part hiddenThe maker is named in 13 other entries (being named is not a finding of fault)
Manufacturer
Tesla
What
Two Powerwall units emptied by EV charger
Cause
Charger stayed connected after grid failure and Wi-Fi loss

Companies named in the reporting of this entry (being named is not a finding of fault): Tesla

What happened

A homeowner reported that a house with rooftop solar and two Tesla Powerwall 3 units lost its battery reserve during a grid outage. The account said a driver struck a transformer on a nearby main road at about 10 p.m., after which the house switched to battery backup without the occupants noticing. A charging request from a Rivian electric vehicle was reported to have continued through a Wallbox charger and emptied both Powerwalls in about one hour. The same account said Wi-Fi went down during the outage and that an automation intended to stop charging may not have worked. The place, date and any independent confirmation were not reported.

Contributing factors

As reported, a high-draw EV charge continued after the switch to backup. Loss of internet connectivity may have left cloud-based control of the charger unable to stop the session. No independent check of the outage or of the charger behaviour was reported.

Lessons learned

  1. High-draw loads such as EV chargers should be kept off battery-backed circuits, or disconnected locally when the grid is lost.
  2. Outage plans that rely on internet or cloud automation can fail if the router or the cloud link drops; a local interlock is more reliable.
  3. Where network equipment is needed for control, a small UPS can keep it up through a brief interruption.

More lessons on outages, backup supply and restoration, from every incident on the register.

Not yet known

  • Place and date of the incident
  • Independent confirmation of events
  • Reported cause of the transformer strike

This entry is updated when these are reported. Get an alert for the next one like it.

Source

thecooldown.com

Published 2026-09-25. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.

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Chart to reuse with this story: Hybrid co-located incidents in the United States, by year, free with a credit (PNG).

Hybrid co-located incidents in the United States: 8 entries, with a free alert for the next one.

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