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Comment by tshaddox | Hacker News Reader

Even if you can’t easily recharge, it’s a great way to power your home for a few days. It’s arguably a very cost-efficient home backup solution, assuming you were already in the market for an EV.

A Cybertruck has nearly 10x the battery capacity of a single Powerwall, and to buy that much Powerwall capacity would cost at least as much as a Cybertruck. Even a Tesla Model 3 (which now supports home backup) is over 5x Powerwalls.

You still have to pay to install home backup support on your home’s breaker (at least $10k), but you don’t need anywhere near the amount of very expensive supplemental home batteries.

Also, even an EV with a 120V outlet and no home backup support could be very useful for recharging a portable battery bank.

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> You still have to pay to install home backup support on your home’s breaker (at least $10k),

$10,000 to install a socket, a breaker, and a transfer switch?

Surely not.

We priced this out when we bought our Ford F150 generator on wheels. It was maybe 3k including parts and labor. We opted to go without the fancy socket and breaker, and it cost us about 600 USD.

The cheaper version even, which may be what you are talking about, is literally just a piece of plastic or metal called an interlock on the breaker box that prevents the main from being on while the generator inlet is supplying power (backfeeding the line). Then all you need to do is install the inlet on top of that which when I did this a few years ago was around $1,000 USD all in parts and labor.

Electricians like their transfer switches because they are right sized and everything, e.g. they are more foolproof for the end user to operate, but the interlock approach actually gives you more control because every breaker is allowed (a transfer switch will only expose some small subset of all your breakers usually), you just have to manage the power supply yourself.

Sorry, that’s for a full Tesla Powerwall (which includes its own 13.5 kWh battery) which is required to use the recently-announced Model 3 and Y home backup feature. The Cybertruck only needs the gateway and wall connector, which is still $2k plus labor.

Sadly in CA…

Whenever I get quotes for anything electrical, it falls into the territory of “not worth doing unless I learn how to do it myself.” I’d like to upgrade my home to 200A service, but the all-in cost estimate for hydrovac service, panel upgrade, etc. is like $50k.

Some one mentioned something similar about their Ford Lightning in a previous thread. If a whole truck with batteries cost less than the same bare batteries then people buying powerwalls are getting absolutely screwed.

I’m not that familiar with the Powerwall ecosystem, but the equipment and installation that connects to your breaker is non-trivial. But I’ve seen people who add bulk OEM batteries to other home backup systems and those are fairly cheap.

Regardless, the thing that’s really great for cost effectiveness is that the same large battery can be used everyday for driving and also used rarely for emergency home backup systems.

Its still a margin issue. The Powerwallproducer wants their 20% margin, the car company might want there 20% too, but from the whole truck.

The battery installer probably chargers a 100% markup.

10% to pay for their costs - materials and labour

90% to pay for their new Cybertruck financing

More like the people buying electric trucks got incredibly good deals, which is why the trucks are all going out of production.

You want at least one actual PowerWall so that your house doesn't go down when you take your truck on an errand. But yeah, if you're buying 4+ PowerWalls you're probably better off getting an EV with V2H capabilities instead.

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