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

pilaenergy.com

211–220 of 492 posts

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

#211

Definitely a product I've been thinking about... Lead-acid based UPC products have lingered on way too long into the lithium battery age. I had a lead-acid based UPS which I plugged one DSL modem and my cordless telephone base station into the wall which would give me 3 days of modern communications into a power outage, which happens quite frequently in my location. Once my DSL got upgraded to fiber-to-the-node (with…

Sounds like you need Starlink.

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

#212

Earlier quoted context omitted.

I'm not a fan of these devices in general as I'm more of a DIY, but... A Ecoflow Delta 2 Max is $1100, gives you 2kWh capacity and 1000W of solar input. if you have a power outage, you can actually keep it topped off w/ solar while keeping your fridge, gas furnace, etc running. If you're gonna hang a wire out the window, why pay the premium for the pretty enclosure and screen?

Not to hard pivot but any DIY links you’d recommend? I’ve been getting into this field and would like to DIY something around this scale. Keep a fridge running, maybe have a little dc circuit for a home lab.

In addition to Will's channel, don't overlook thermal battery links, too, which often can be made out of old water heaters that folks dump on craigslist all the time. The gist behind thermal batteries is to help with the (solar->battery->coil->hot water) efficiency loop by changing it to (solar->coil->sand->hot water) e.g. https://hackaday.com/2022/11/21/making-a-do-it-yourself-sand... (I love his channel, too) or https://www.technologyreview.com/2024/04/18/1091481/how-to-b...

They also have vastly different failure modes than pumping a bunch of DC voltage into battery cells

There was also recently a post about flow batteries https://news.ycombinator.com/item?id=41235789> which are also very interesting to me, but I haven't gotten far enough into that learning curve to know if they're a good fit

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

#213
In California, you can purchase a 14.3 kWh battery for $3,500, which qualifies for a $2,500 SGIP rebate from the state plus a 30% federal rebate. I find this concept interesting, but the cost is quite high considering it’s literally hundreds of dollars less money to just get a 14.3 kWh battery.

https://bigbattery.com/products/48v-eg4-powerpro/?srsltid=Af...

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

#214

I love the design, but I wonder about the "selling feature". How many people regularly experience power outages (ok, if you're American relying on Canadian electricity, you might have a right to be concerned). I'm surprised you're not touting the "save on your power bill" benefits. Could this not store power when rates are low, and use the battery when rates are higher, while maintaining a balanced minimum storage am…

It’s definitely an important feature & will help reduce the purchase price. Especially charging from home solar since it most solar in the US gets installed without a battery.

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

#215

Earlier quoted context omitted.

Great points! This is meant as whole room backup - so it’ll keep your fridge (and a few other small devices like wifi, etc) running for 2-3 days - a pretty long outage. It’s basically a huge, 21st century UPS. It can also do arbitrage and charge when it’s cheap and deploy the power when it’s expensive. The main problem with a powerwall is it doesn’t work for renters, and costs 20,000+ (and permits, etc) if you do own…

Bullshit on the fridge. A modern day french door uses almost 2 kWh per day at the mid range model level (which really isn't that different from older top freezers). Higher end fridges use even more. The 1.6 kWh capacity isn't enough for 2-3 days.

Wow that’s crazy! What fridge is that?

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

#216

I love the design, but I wonder about the "selling feature". How many people regularly experience power outages (ok, if you're American relying on Canadian electricity, you might have a right to be concerned). I'm surprised you're not touting the "save on your power bill" benefits. Could this not store power when rates are low, and use the battery when rates are higher, while maintaining a balanced minimum storage am…

> How many people regularly experience power outages Anecdotally in a major city it was rare I would not have a power outage several times a year. In a more rural location now, it's rare I have a month without a power outage, some very extended. We have a backup generator and it has saved our frozen foods at least a dozen times over the last few years. Installing a backup generator costs about $10k for a whole house…

If Pila existed before you bought the generator, would you have bought a Pila?

Does your generator require maintenance? Is it loud?

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

#217
post #163

Earlier quoted context omitted.

Great points! This is meant as whole room backup - so it’ll keep your fridge (and a few other small devices like wifi, etc) running for 2-3 days - a pretty long outage. It’s basically a huge, 21st century UPS. It can also do arbitrage and charge when it’s cheap and deploy the power when it’s expensive. The main problem with a powerwall is it doesn’t work for renters, and costs 20,000+ (and permits, etc) if you do own…

I can’t afford something like this but I would absolutely get something similar to this if I could. My sump pumps are literally one of my biggest home ownership worries.

My dad put together a backup system- in spring time, they get weeks of water running at their house, so he's got two pumps on two separate batteries in case either pump or battery dies.

You can even get an all in one system for around $200 if you want to save up for something more robust:

https://www.homedepot.com/p/Basement-Watchdog-Emergency-Batt...

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

#218
post #208

It looks beautiful. But I honestly don't understand what the market is. OP answered in one of the comments that it will run a single fridge for 32 hours. I understand the benefits of a UPS that will run your desktop computer during a brief power outage of a couple of hours. And I understand a generator that will keep your house running for 10 days after a natural disaster. And I understand a Powerwall that can suck u…

I agree that this doesn't seem useful for time of use arbitrage. I think it depends on what your electric outages look like. Short outages, a desktop ups probably makes sense. But if you regularly get 12-36 hour outages, this might be a reasonable product for you. Personally, I expect two nines of utility power, so something like this could possibly work (but I already have a 35kW propane fired standby generator)

Yeah I get that, this will last longer than a UPS. I’ve thrown away a few in the last couple years that broke. That’s the lead acid UPS vs. LFP chemistry at work.

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

#219

Earlier quoted context omitted.

And Italian. It’s actually named after Alessandro Volta’s (the guy who named the Volt) name for the "Pila di Volta" - his stack of soaked rags that stored electricity, or what we'd nowadays call a battery stack. Pila is a Pile that stores electricity or a Battery - Pila :)

Huh. I always sorta associated the word with a voltaic pile ( https://en.wikipedia.org/wiki/Voltaic_pile ), which... https://en.wiktionary.org/wiki/pila gives an etymology of coming from Latin's "pīla" = "pillar", which feels close? Or maybe it's just a coincidence.

That’s 100% it! It was named after the Voltaic Pile or Pile/Stack of Volts.

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

#220
Judging by the negativity here you're going to be a massive success -- search up the dropbox, airbnb, coinbase and ethereum launch threads if you want to feel good about where you're at. :)

That said, I like this idea -- a modern coordinated UPS. I live in an area where people have 3-10 days a year of no power; being able to pick and choose what power they'd use during an outage would be a significant benefit to them.

Good luck!

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