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

pilaenergy.com

221–230 of 492 posts

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

#221
post #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...

You will still need a (hybrid) inverter to use it so add at least $500 on top of that. And that money doesn't really get you a unit which is capable enough to really make use of a battery of this size.

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

#223
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, this sounds perfect for the suburb I grew up in - a couple outages a year, but they only lasted about half a day.

"Don't open the fridge so everything stays cold" is a lot more difficult with three teenagers.

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

#224

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.

> 2kWh per day.

That’s a lot of energy! What fridge do you have?

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

#226
post #222

This is great for devices plugged in to the same circuit. Can it provide power to separate circuits? Such as fixed lights, which are typically on a separate circuit from power outlets.

Great question! Unfortunately no, it'll only power devices that're plugged into it. It's basically like a very large, connected UPS.

It's unfortunately illegal to push energy back into the circuit without a permit in all states except Utah in the US :D

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

#227
post #223
post #208

Earlier quoted context omitted.

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, this sounds perfect for the suburb I grew up in - a couple outages a year, but they only lasted about half a day. "Don't open the fridge so everything stays cold" is a lot more difficult with three teenagers.

Pila has temp sensors that can monitor fridge & freezer temp to give you piece of mind.

So hard to keep the fridge closed & how do you know whether the food is still safe?

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

#228
post #142

Earlier quoted context omitted.

Feed power in through one circuit back to the main board, on a different circuit cause a short, main breaker trips, main board is now isolated from the grid. Technically possible, irresponsible, bad advice, and probably won’t work in most scenarios.

Doesn't work and would likely cause fires. First the smaller circuits will trip first, that's where the current is actually flowing, there wouldn't be any actually flowing through the whole house breaker in your idea. The main circuit to your house is 100+ Amps (this would be a tiny old circuit most houses have larger main feeds these days) at least. You'd have to feed at that much through the main disconnect for it…

You’re right, my mistake.

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

#229
I’ve got several Jackery batteries at this point and my wife complained that they were a waste of money right up until our breaker panel gave up the ghost and we were without power for several days. Your product is more expensive but not significantly so, and has some nice features the Jackery does not. For homeowners like me though, all of this becomes unnecessary once I can power the house from my car.

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

#230

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…

Thanks so much! We'll address as much feedback as we can of course, but I hear you :D
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