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Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

pilaenergy.com

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Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#471

Post by jodoherty »

quesera wrote: post #273
jodoherty wrote: post #187

Earlier quoted context omitted.

Do you have any examples? I haven't seen what you're describing despite shopping UPSes, but something less than $100 that could last 10+ hours would be amazing. My $200 1500VA/1000W CyperPower UPS could handle a short one or two hour storm, but storms can last for 10+ hours here during the wet season. One long power outage could cost me a lot more than $1000 in basement damages (my basement is finished). A comparable…

It depends on the wattage and duty cycle of your sump pump. My experience with sump pumps is low wattage and intermittent use. Sounds like this does not correspond to yours.

That makes sense. Mine runs every few minutes sometimes in heavy rain.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#472

Post by lucb1e »

dzhiurgis wrote: post #403
lucb1e wrote: post #270

Earlier quoted context omitted.

> The average fridge loss is estimated at $300 per outage Holy crap, I don't think our fridge fits 300 dollars' worth of food. We have trouble fitting a ~140€ grocery run into the fridge and probably at least half of that is non-refrigerated products. Hard to say how many days' food this is, probably close to a week, so a 36h+ outage (where the fridge actually got warm for a while) would have an average occupancy of…

It's pretty simple - europeans are more frequently going to shop. US/AU/NZ drive and do a bigger shop to last half a week or so. Also most of Europeans live in apartments - your power cables are underground. In suburbs, putting cables are underground is too expensive and overhead wires are easily damaged during storms.

Yeah I'll never understand the people that go to the store daily or bidaily to see what's for dinner tonight, that seems like a big waste of time with increased exposure to whatever flu is currently popular. On the other hand, the planning involved in "where will I be, what will I be doing five days from now, will the potatoes have sprouted and the tomatoes be mouldy again by then" is also not fun, but yeah half a week (3-4 days) is the minimum of how often I ideally go

Anyway I was keeping in mind (I mentioned) that one might store a week's worth of food, but now that I consider it again, also in the context of apartments vs. bigger buildings: I don't have a big family that lives with me (no children or parents or so, just partner), so I should perhaps multiply this by two extra persons. It still doesn't add up to more than half of the 300USD figure, but it's less outlandish if the 'average' household is considered to be 4 people who all eat adult-sized portions (as teenagers probably already would)

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#473

Post by chadconway »

linsomniac wrote: post #455

Off topic of strictly Pila, but coleashman is following and might have some interesting insight: What would a "modern" house electrical system look like? I'm in a '70s house, but even new builds I get the sense unless you're putting in a powerwall at build time, they aren't very interesting; just a meter and a load center and feeds. And maybe that's the way to do it, not do anything fancy until you put in a Powerwall…

I think the modern path for new builds is a SPAN Panel which adds an MID, breaker level load control, & flexibility of install.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#474

Post by chadconway »

rsync wrote: post #449

I’m confused by two things… First: this is an electrical power source with a male plug… And I understand the intelligence inside of it, but… can this possibly be code compliant? Something similar to this is often referred to as a Suicide cord … Second: this is back-feeding electricity into the power grid and, again, I understand you can address this with onboard intelligence and millisecond switching… But I don’t thi…

Suicide cords are from dumb generators. Pila has smart safety controls that don’t feed power back through the plug unless it’s connected to grid.

Utah just passed a law allowing this & Germany has allowed it for years.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#475

Post by chadconway »

rahimnathwani wrote: post #64
chadconway wrote: post #12

Earlier quoted context omitted.

Technically Pila is able to push power back through the home when the grid is up. Utah passed a law to allow this. We hope to bring this potential to all states. https://pv-magazine-usa.com/2025/03/05/balcony-solar-gains-u...

But 'when the grid is up' isn't the time you'd want to feed power from one outlet into the others. It's when the grid is down you'd want to do this, no? I guess you could flip the trip switch to isolate the circuit?

Yes & no, there are two reasons to push power back: 1- to save money on energy, charge when cheap discharge when expensive. Pila can do this. 2- to backup. Pila can’t do this. It can only backup appliances plugged into it.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#478

Post by gwbas1c »

xtracto wrote: post #120
gwbas1c wrote: post #73

So it's just a smarter UPS, (that can integrate with solar panels) but you only compare it to a standby generator. Seems like you need to compare it to a UPS too, because that's what it really, really is.

At first I thought it was some kind of UPS that would automatically "inject" AC to the house when it detected that there was no current in the mains (hence the connection to mains). But it seems it is just a glorified UPS... is that what the tesla "Wall" is?

> But it seems it is just a glorified UPS...

Yes, exactly.

> is that what the tesla "Wall" is?

You mean the Powerwall. It's more like a standby generator than a UPS, because they either backup the whole house, or a subpanel. There is an automatic transfer switch, just like a standby generator.

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The big differences between a Powerwall and a standby generator are:

The Powerwall needs no maintenance. (Standby generators need annual maintenance, oil changes, new spark plugs...)

The Powerwall needs no external fuel source. (No tank of diesel or propane, no need to have a natural gas service to the house.)

The Powerwall can be configured to only charge from solar. This allows owners to take advantage of renewable energy incentives.

The Powerwall can join Tesla's virtual power plant, and feed back into the grid, thus generating revenue. (Basically, charge from solar when demand for electricity is low, and feed back into the grid when demand for electricity is high.) Tesla paid me over $1000 for 2024.

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(In case you didn't know, a standby generator is the kind that automatically starts and powers your house in a blackout. A portable generator is, well, portable. If you have one, you have to manually start it, and either trip over extension cords, or wire in a manual transfer switch to your house.)

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#479

Post by chadconway »

bradknowles wrote: post #470
rsync wrote: post #456

Earlier quoted context omitted.

The OP described it as plugging into mains outlet and then, in the event of an outage, feeding power back into that mains circuit to power every outlet on the circuit. Did I misunderstand?

The description was very poor. They could only feed power back into the one circuit that hardware is on, and the would also be a violation of multiple safety standards, as well as the National Electrical Code. That’s a good way to get someone hurt or killed, and to have your ass thrown in jail for sporting such a stupid device. This is why you have lockout devices on breaker boxes, if you’re going to have an emergenc…

This is mostly correct. One additional feature is that it can back feed when the grid is up. This allows you to save money on your energy, charging when energy is cheap or from solar and discharging when energy is expensive.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#480

Post by chadconway »

iskyex wrote: post #448

A beautiful UPS. But my experience in recent years has shown me that some good-looking devices are often just superficially attractive and not more stable than older devices. Could you provide some comparisons on the website with existing UPSs? (For example, stability, safety, etc.) Also I'd prefer to keep some more critical systems running (like my homelab server). Can this UPS prioritize power to these devices?

Yes, it has 4 outlets and can turn them off automatically based on your priority settings.
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