Facing repeated PG&E shutoffs at a cabin in the Sierras in California, a Reddit user asked whether a pair of Powerwall 3s could feed a 200-amp service panel and, when the grid was down, be recharged by a 6-kilowatt gas generator.
Users were decisive, highlighting that home battery systems do not all handle extended outages the same way.
Here's what to know
Posting in r/TeslaSolar, the cabin owner described ongoing utility trouble, writing, "PG&E starting to hold us hostage with power interruptions during summer/fall, and occasionally a tree falls in the winter and power interrupted for a couple days."
They asked whether the Powerwalls could be connected to their service panel, charge from the grid when power was available, and then take a recharge from the gas generator during an outage. They also said they already had a 30-amp transfer switch.
"If you want generator support, don't buy a Powerwall system," one commenter said, while another added, "Tesla Powerwalls can't be recharged from generators."
If you're weighing a similar setup, exploring EnergySage can help homeowners compare home battery storage options and get competitive installation estimates. EnergySage has teamed up with electrification brand Qmerit to help homeowners get the best price on home battery storage solutions.
More background
One user focused on how the switching might work, saying a Powerwall is isolated to prevent power from backfeeding to the grid. In the proposed scenario, the cabin could wind up with "two separate transfer switches" that keep generator electricity from flowing back into the batteries.
Battery storage can lower energy costs and give households energy independence by keeping stored electricity available for essential loads when utility service is interrupted.
Crushed by your bills? See instant solar savings from vetted installers in just a few clicks With energy prices through the roof, there's never been a better time to go solar — and EasyHome can help you find the best prices from the best installers in your area. EasyHome takes the guesswork and headaches out of energy upgrades by showing you estimated savings from a network of vetted local partners. To get started, just enter your ZIP and share a few details about your home — seeing your estimate is really that easy. |
Someone else with a Powerwall 3 recommended adding capacity instead of relying on generator charging, writing: "I would just get an expansion pack if it were my house. Our 'free' gas freezes."
What can be done?
The practical takeaway from the thread was that generator-charging compatibility should be checked before any battery purchase. In this case, commenters said Powerwalls could not be recharged by the cabin's gas generator during an outage.
Some Redditors named other batteries they said were better suited to generator backup.
For people who do not need a whole-home battery, Pila offers plug-and-play batteries that are priced at a fraction of what whole-home backup systems cost.
Battery storage can be a smart way to ride out outages, reduce energy bills, and rely less on the grid but only if the system matches the backup plan. If generator charging is part of that plan, it needs to be verified from the start.
Get TCD's free newsletters for easy tips, smart advice, and a chance to earn $5,000 toward home upgrades. To see more stories like this one, change your Google preferences here.
