8 ms·

Buy Your Friends Batteries

147 points by domenkozar 2mo ago

deleted 2mo ago
[deleted]
wheatone 2mo ago
[flagged]
- domenkozar 2mo ago
  This battery uses a safer type of lithium chemistry that is less prone to overheating, though no large battery is risk-free. Water is used by firefighters to cool battery fires (they can reignite tho). Install it outdoors or in a detached garage, away from anything flammable. Never in a bedroom, hallway, or escape route. There are newer batteries tech that can't inflame.
- beaviskhan 2mo ago
  Most modern batteries like this are weatherproof and can be mounted outside the home. Most modern batteries use LiFePO4 chemistry, which while not perfect, is much less risky in terms of thermal runaway than older lithium ion batteries.
- fhdkweig 2mo ago
  The Tesla Powerwall is only slightly larger than a pizza box and can be mounted directly on the wall. Most of the below images are outside the house, but some are also in the garage. https://duckduckgo.com/?q=tesla+powerwall&ia=images&iax=images https://duckduckgo.com/?q=tesla+powerwall&ia=images&iax=imag...
  - thejazzman 2mo ago
    Tesla powerwall is 44” x 24” Where are you buying your pizzas?!
  - ykl 2mo ago
    I have two Powerwalls mounted on my house and while I think they're fantastic and pretty compact for what they are, I would not describe them as anywhere near the size of a pizza box (unless you mean one of these things [1]). [1] https://www.scottspizzatours.com/blog/worlds-largest-delivery-pizza/ https://www.scottspizzatours.com/blog/worlds-largest-deliver...
toomuchtodo 2mo ago
Great piece and post, love the concept!
- domenkozar 2mo ago
  Let's go!
Retr0id 2mo ago
> Create a battery birthday club. Buy each friend a battery on their birthday until everyone has one. At that point, wouldn't it be easier if everyone just bought their own? And then whoever has the latest birthday doesn't have to wait a year to get theirs.
- oytis 2mo ago
  But then you still have to buy birthday presents on top of that
  - Retr0id 2mo ago
    If everyone's giving everyone the same gift, it's not really a "gift" any more, more of a p2p buy-now-pay-later arrangement (which isn't a terrible idea, but it's suboptimal for those with later bithdays).
    - blitzar 2mo ago
      Might as well just have an annual theme and try to negotiate a bulk discount.
    - cactusplant7374 2mo ago
      Not everything needs to be optimized. Probably only rich people would engage in such a scheme anyway.
      - Retr0id 2mo ago
        The whole premise here is cost optimization.
        hobojojo 2mo ago
        It's not cost optimization its payment on installments.. Personally, I find it less convenient to have more than 1 bill and a group of 30 paying on average every 12 days probably makes it less convenient for anyone. But there are some strange consumers who like to delude themselves.
Apreche 2mo ago
Anyone who can afford to own a home can afford their batteries and doesn’t need gifts. Renters are not allowed to modify their home in such a way.
- Tepix 2mo ago
  In Germany you can use a "Balkonkraftwerk" that just plugs into any outlet and contributes up to 800W. You can also hook up solar panels to it up to 2000W (makes most sense with batteries). No need for the landlord to agree.
well_ackshually 2mo ago
>sixteen people contribute €100 each; yeah sure everyone has 100€ to spend on friends, at least once a month. What kind of reality does he live in ?
- Hugsbox 2mo ago
  You're getting downvoted, but for real this is so disconnected from what I'd say is feasible for most people. I and most of the people I know live squarely paycheck to paycheck, I can't afford to buy my friends birthday presents at all, let alone set aside that much per month just to put batteries in other peoples' houses. This feels like one of those things where the author doesn't grasp the privilege he lives with.
  - Tepix 2mo ago
    Do they even have houses?
    - Hugsbox 2mo ago
      In some cases yes, and they're not doing much better than I am.
    - ssl-3 2mo ago
      Does having a home inherently change disposable income?
  - Symbiote 2mo ago
    Even where people probably could afford it I think spending €100 on a birthday gift would be excessive. It would be showing off.
  - Majestic121 2mo ago
    Surely not for _most_ people, but for people on Hacker News, in the correct age range to have a house, putting 100e aside really does not seem out of whack. Maybe the author is privileged and it's fine, it's not because you personally can't afford any gift that the author is disconnected, he might not just be talking to everyone on earth.
isoprophlex 2mo ago
> You are also safer during a power outage. The STREAM 5000 provides up to 3 kW of off-grid output. Keep essential devices on its backup output and reserve some battery capacity, and your refrigerator, lights, router, and laptop can keep running when the grid goes down. An ordinary grid connection does not back up the whole house automatically; the backup output must be configured correctly. Being able to cut over your entire house from grid power to a battery requires an invasive, expensive change to most connections. I wish people would stop breathlessly promoting batteries (which are good! we need decentralized storage!) because "you can use them to run your fridge, router, etc". Yes you can, but for almost all consumers it's an order of magnitude more effort and cash compared to just buying and plugging in a battery.
- fhdkweig 2mo ago
  If a fridge is your only concern, they make UPSes specifically for fridges. https://duckduckgo.com/?q=Uninterruptible+power+supply+refrigerator&ia=web https://duckduckgo.com/?q=Uninterruptible+power+supply+refri...
- tonymet 2mo ago
  I disagree. During an outage, you need your fridge and a few other essential items. A novice can plug into the back. The device tells you the load and whether you are exceeding. And you can test it at any time. For $600 you can get started without an electrician. it's the easiest, safest , most affordable and most reliable emergency solution ever available.
  - brk 2mo ago
    For a relatively small battery like that, it's not going to last for days. In the typical outage where that battery would carry you, you can typically just leave the fridge closed and it will stay cold enough to prevent 99% of your stuff from spoiling. For most people (at least the US), it's not super easy to get at the plug in the back of the fridge anyway. Running HVAC is usually more of a concern, especially in winter or peak of summer, and those aren't device that you can hot-plug, and a small battery wouldn't help there anyway. I like the idea of whole-house batteries, but to really make it practical you're talking about thousands of dollars to the battery, install, etc. And you still don't have extensive run time, which is why I think you see most people still leaning towards permanent or portable generators way more than batteries.
or_am_i 2mo ago
How does 12 years required for this scheme to pay for itself stack up against the typical house battery's lifetime?
- strbean 2mo ago
  Sounds like that's roughly the average usable lifetime for the battery, so you will break even on average.
  - deleted 2mo ago
    [deleted]
  - Toutouxc 2mo ago
    Roughly the usable lifetime? Based on what?
    - medler 2mo ago
      The battery linked in the article (https://eu.ecoflow.com/products/stream-series-solar-battery https://eu.ecoflow.com/products/stream-series-solar-battery) advertises a 15 year lifespan and 10 year warranty. Personally I would expect batteries to last longer than that but 12 years feels fair
  - hobo123 2mo ago
    I think most electric car batteries are still at over 80% capacity after 10 years usage, so hopefully you can use them much longer than that. If you only cycle then in the 20-80% range, they'll last much longer (at least for NMC cells, not sure how LFP works).
    - vel0city 2mo ago
      I'd imagine most electric car batteries aren't fully charging and discharging every day. That makes quite a bit of difference in wear! Tons of EVs these days are being made with what, 200-300mi range of battery pack with some internal buffer as well so they're never really going 0-100%? So what, we'll be generous here about the 20-80% and think 160mi of range used every day. That's 58,400mi of driving per car! The average US car does closer to 14,000mi. Being generous, that's 4x the wear cycles of a normal US automobile.
jerlam 2mo ago
> 2. Confirm that their home, meter, and electricity contract are compatible. This seems like the hardest step. The costs of "just a battery" are much lower by comparison.
- jandrese 2mo ago
  You don't necessarily need to export power, especially for a small battery like tihs. Charge it up when power is cheap, and then configure it to discharge when power is expensive but only to match your current usage. You will need a CT on your main feed for it to balance against, but it can be done.
archydeb 2mo ago
And if you’re in the UK, wire them up to Axle Energy (plug-in batteries aren’t actually legal here yet, but likely to become so next year!)
mindslight 2mo ago
Call me old fashioned, but I just bring a can of gasoline and a pile of super soakers. While I do like the idea in theory, I don't love the inherent nudge towards off the shelf productized energy storage that will be placed somewhere without much of a plan, and then basically invites rewiring with extension cords. I get how those things are appealing for camping or determined apartment DIYers at the like, but moving them from a seek-them-out "pull" dynamic to a here-you-go "push" dynamic seems like asking for problems from people not thinking too much about storing 5kWh.
Tepix 2mo ago
> €1,600 for 5 kWh Those prices are high. You can get 2.56kWh for 270€ on Aliexpress, delivered locally from Germany.
- microtonal 2mo ago
  2.56kWh for 270€ on Aliexpress What could possibly go wrong? The things that people do. Personally, I'd like the company to be in the EU so that I can at least sue them if it burns down the house.
- markvdb 2mo ago
  Most of these are illegal to install in Belgium though. Anything connected there needs national grid type approval.
- pornel 2mo ago
  > Aliexpress There are even cheaper ways of starting a fire.
jambalaya8 2mo ago
No.
thraway3837 2mo ago
You don't really need this, if you have an EV with V2X technology. There's already charging products that work seamlessly: https://www.youtube.com/watch?v=H0WGl_U5azs https://www.youtube.com/watch?v=H0WGl_U5azs and you have 100kWh of capacity, so you could sit out an outage for a long time. You can also configure the % cut off for the EV, so you still have enough left to drive if you need to leave. EV battery degradation from this use case is irrelevant. EVs are consistently hitting 300,000 miles with 90% capacity, so let's not belabor this point.
- hypfer 2mo ago
  > EV battery degradation from this use case is irrelevant. Nope.
- adolph 2mo ago
  The thing about the EcoFlow Stream is that has things like phase alignment which allows it to be plugged directly into a household outlet without transfer switches to segregate grid phase from the phase of power created by the V2X inverter's phase. It also handles solar input. I suppose that future V2X systems will incorporate direct plug-in tech, but note the transfer switch used by the system in the video.
ortusdux 2mo ago
This is what government subsidies/rebates are for - https://news.ycombinator.com/item?id=49298910 https://news.ycombinator.com/item?id=49298910 Gift should be ... gifts
sailfast 2mo ago
The 12 year payoff IF you manage the arbitrage properly really made me wonder why on earth you would buy one of these. I want one, yes. But it sure as hell wouldn't be to save money. It'd be to have something if and when the grid falls over due to negligence.
balderdash 2mo ago
11-13yr payback on something that is going to degrade ~3-4%/yr for 10 years (and limited terminal value) doesn't seem like the greatest investment unless you think the arb is going to widen a ton.
- sdthjbvuiiijbb 2mo ago
  And any arbitrage is also trivially exploited by the electricity company, who has a much greater financial incentive and scale, so there's really no reason to think that it's going to widen in the future either.
  - bluGill 2mo ago
    You could exploit it yourself, but only if you have several million to invest, less than that and it isn't worth the bother for the electric company to talk to you. Even at ten million invested you really need to have this is round one in your proposal with the understanding you intend to invest a lot more when it proves in the real world to work like you expect.
  - delecti 2mo ago
    Until grid-scale batteries are more established, you're helping the electric company, and that's why they're exposing the arbitrage. They're providing the incentives to nudge demand, so a home battery is doing exactly what they want (use more at time X, use less at time Y). Otherwise they'd just have the 24/7 price be whatever it currently costs when the supply and demand curves are tightest for them (when demand is highest and/or supply is lowest).
- mosselman 2mo ago
  Let's assume the calculation is correct and you actually earn back in 11-13 years. You are better off investing the money in something like the S&P 500 where you'd double your investment in about a decade without the hassle. Things will start to get interesting where €1600 don't buy you 5kWh but double or triple the amount. I can imagine most people are better off either investing like I said or in insulation.
scaredreally 2mo ago
At my mother's workplace, there was a group of coworkers who each donated an amount of money per paycheck. Each paycheck, one coworker would get the lump sum that was collected for that paycheck. Similar concept to the one described here. They called it "susu" or something to that effect. If I remember correctly, it got messy when people would leave the workplace or when, occasionally, someone would get robbed on the way home.
- mtlynch 2mo ago
  I read the book Poor Economics[0] around when it came out, and it described something similar. For people who don't have access to banks, they form "savings clubs" where there will be, say, 12 people who put in $100 per month, and one person takes the pot every month. The idea is that if you keep the money yourself, then you're socially pressured to spend it when there are holidays or guests, but if it's locked up in the savings club, you can't spend it, and then you get a big lump sum to spend on a large purchase that would be otherwise hard to save for. [0] https://en.wikipedia.org/wiki/Poor_Economics https://en.wikipedia.org/wiki/Poor_Economics
kortzeus 2mo ago
The only downside is that the battery won't last 11 years with daily usage
hypfer 2mo ago
A Marstek Venus A 2.12kWh expansion module currently costs 180€ with a bunch of special aliexpress discounts. The whole system is.. not great, but it's even cheaper to have a battery than this post makes it sound.
tristor 2mo ago
This is interesting, but is 3kW enough to be useful? What is the latest when it comes to home batteries? Has management gotten better to be smarter?
SubiculumCode 2mo ago
People don't tend to buy people large furniture because it's rude to assume that theyll want to keep something large and relatively permanent, much less something that requires an electrician to install.
vel0city 2mo ago
So I could buy a battery for ~$1,850 today that won't even break even in a decade (and hope everything goes well with this plan, not guaranteed in the slightest), or I can buy a 10 year US treasury note that'll give me another $1,000+ in profit at the end of the decade. Remind me why I should buy the battery? It clearly can't be because it makes financial sense to just have the battery.
mistivia 2mo ago
I don't think installing this kind of system at home is a good idea, especially considering the risk of fire. The amount of energy contained in a 5 kWh lithium battery is terrifing.
- compiler-guy 2mo ago
  There are numerous systems available for this type of system that are professionally designed and built, and satisfy all kinds of local codes. Many are in use all over the world in off-grid cabins and similar. You do need to take care that they are installed correctly, and maintained properly, but that isn't much different than a natural gas connection, or even normal everyday electricity.
hobo123 2mo ago
Strange article, even though the idea is nice. $200 birthday presents might be a thing in America in some circles, but for German standards that is ludicrous (even 50 bucks is quite a lot, and then you need 32 people). I also don't get his example calculation. He mentions that average price in Germany is 38c/kWh, but in the table it's suddenly 4c min vs 13c max (or 40 vs 133?). That doesn't compute.
- skitsofrandom 2mo ago
  [dead]
Johnny555 2mo ago
>thirty-two people contribute €50 each. I guess Europeans have more friends than Americans -- I can't think of 32 people I'd invite to a birthday party, and certainly not 32 people that I'd expect to give me a €50 gift. I haven't received a real birthday present from friends (beyond a cheap gag-gift) in decades.
chaostheory 2mo ago
As the post already mentioned, also great for blackouts, of which more are coming for the developed world given climate change and infrastructure failure
_ink_ 2mo ago
Germany is unfortunately not a good place to do this. The additional fees that you need to pay on top of the actual energy price are simply too high. And currently there is Katharina Reiche in charge which is actively fighting concepts like Energy Sharing.
imbusy111 2mo ago
The hybrid inverter that allows you to plug the battery into your house circuit (DC -> AC) seamlessly is around $2-3k + installation cost, cause you're touching the main panel. Why isn't that in the calculation?
- domenkozar 2mo ago
  You plug it into a socket.
  - compiler-guy 2mo ago
    Plugging a power-supply into a normal outlet like this is legal in many places, and illegal in many others. Check local code before proceeding!
xur17 2mo ago
Do any US states allow plug in batteries like this (I know some allow plug in solar)? The installation cost of a whole home battery is what has kept me away so far.
- daxelrod 2mo ago
  That’s a good point. I had assumed the states allowing plug-in solar also allowed batteries, but according to https://pluginsolarguide.com https://pluginsolarguide.com , it’s only Utah so far.
rmykhajliw 2mo ago
Welcome to Ukraine where local people installed around 8GWt of batteries at home mostly because of huge outages after missile and ballistic terroristic attacks. Batteries installation is not about money , average LiFePo4 battery life is around 10 years, so you will save nothing, unless you have some local generation like solar panels. In this case you could shrink payback time to 5 years instead of 10 and it makes some sense. But the biggest problems here 2: 1. there a critical point after installing a huge amount of balance batteries the diff between day/night hours would be mitigated. And prices may down 30%. As result economical factor of installing energy storage systems would be very questionable. However cheap energy will increase energy usage by homes and industry and this may/might/probaly/i_hope. boost economy 2. The second factor riskier because when many people are installing energy storages and become independent of power grid, or even disconnects from the grid, there still exists power grid you have to support. Right now the price of grid support included in energy bill for electric company. The grid usage price is stable , it doesn't matter you support 1 person or a 1mln residents city. So the less people are using THE GRID - the higher prices for the rest people. And those high price forces rest people to disconnect from the grid. In general we may/I_hope_not to have situation with plenty energy islands and no more national grid systems
ivanjermakov 2mo ago
> keep essential devices running when the power goes out I guess it's very location-specific, but I haven't had a power outage longer than 1 minute in the past 5 years.
- nancyminusone 2mo ago
  You are correct. My area has had 3 in the past 5 months.
CGMthrowaway 2mo ago
How do I properly think about the fire hazard posed by a big battery in my house?
stogot 2mo ago
The example prices of kWH in this article are inconsistent
leemelone 2mo ago
how often do I have to buy a new one? Batteries are one of the highest cost and most consumable items I can think of.
cloudie78 2mo ago
[flagged]
xet7 2mo ago
It this ad from some battery company?
Tharre 2mo ago
There are two issues with the articles calculations, that end up making the already bad payback time even worse, before considering opportunity costs. Numbers are for Germany since that's the more favorable case: 1 - degradation: assuming the 15 years battery life / 10.000 cycles number from the datasheet is accurate, and that the manufacturer considers 70% capacity end-of-life, this pushes the payback time from 11.1 to 12.7 years. 2 - The article calculates the savings with: > daily saving = 4.5 × expensive price − 5 × cheap price but this is wrong because it assumes that grid charges fully cancel out. The article generally does a poor job at explaining this, but essentially it proposes you overbuy electricity when it's cheap and use it when it's expensive. The difference of those two, €0.133/kWh - €0.041/kWh is much smaller then the average electricity price of €0.3869/kWh because the latter also includes taxes and grid charges. So with 90% efficiency they end up with the formula above, but completely ignore the fact that from the grid's point of view, the total electricity consumption increased. On the flipside, it's also taking EPEX prices directly, pre-VAT, so you actually save 19% more then the difference 0.133 - 0.041 = 0.092. So the actual formula should be: > daily saving = 1.19 × (5×0.9 × expensive price − 5 × cheap price) − 5 × (1−0.9) × grid charges At a average rate of 21 cents/kWh for total grid costs (including VAT) that comes out to a payback time of 13.71 years. So yeah, buying batteries alone doesn't make sense. You need solar or wind to charge them, so you actually avoid the grid charges. So that instead of saving 10 cents you save 40.
ValentineC 2mo ago
How long do such batteries last? I remember having to replace the lead acid battery in my UPS every 2-3 years, which seemed like a waste of money considering my country's power grid is fairly stable apart from the occasional blackout from lightning strikes.
two_handfuls 2mo ago
A home battery you can just plug in. Interesting. Are those legal in the US?
turtlebits 2mo ago
I hate being a broken record, but batteries are $100/kWh now, sometimes less. Don't buy proprietary. You can get a 3kW inverter and 5kWh of battery for ~800 USD. Want more storage or output? Just add batteries or swap out the inverter.
radar1310 2mo ago
That’s the longest ad I’ve read in a longtime.
nc55g3g 2mo ago
[dead]

147 points by domenkozar 2mo ago

deleted 2mo ago

[deleted]

wheatone 2mo ago

[flagged]

domenkozar 2mo ago
This battery uses a safer type of lithium chemistry that is less prone to overheating, though no large battery is risk-free. Water is used by firefighters to cool battery fires (they can reignite tho). Install it outdoors or in a detached garage, away from anything flammable. Never in a bedroom, hallway, or escape route. There are newer batteries tech that can't inflame.
beaviskhan 2mo ago
Most modern batteries like this are weatherproof and can be mounted outside the home. Most modern batteries use LiFePO4 chemistry, which while not perfect, is much less risky in terms of thermal runaway than older lithium ion batteries.
fhdkweig 2mo ago
The Tesla Powerwall is only slightly larger than a pizza box and can be mounted directly on the wall. Most of the below images are outside the house, but some are also in the garage. https://duckduckgo.com/?q=tesla+powerwall&ia=images&iax=images https://duckduckgo.com/?q=tesla+powerwall&ia=images&iax=imag...
- thejazzman 2mo ago
  Tesla powerwall is 44” x 24” Where are you buying your pizzas?!
- ykl 2mo ago
  I have two Powerwalls mounted on my house and while I think they're fantastic and pretty compact for what they are, I would not describe them as anywhere near the size of a pizza box (unless you mean one of these things [1]). [1] https://www.scottspizzatours.com/blog/worlds-largest-delivery-pizza/ https://www.scottspizzatours.com/blog/worlds-largest-deliver...

toomuchtodo 2mo ago

Great piece and post, love the concept!

domenkozar 2mo ago
Let's go!

Retr0id 2mo ago

> Create a battery birthday club. Buy each friend a battery on their birthday until everyone has one. At that point, wouldn't it be easier if everyone just bought their own? And then whoever has the latest birthday doesn't have to wait a year to get theirs.

oytis 2mo ago
But then you still have to buy birthday presents on top of that
- Retr0id 2mo ago
  If everyone's giving everyone the same gift, it's not really a "gift" any more, more of a p2p buy-now-pay-later arrangement (which isn't a terrible idea, but it's suboptimal for those with later bithdays).
  - blitzar 2mo ago
    Might as well just have an annual theme and try to negotiate a bulk discount.
  - cactusplant7374 2mo ago
    Not everything needs to be optimized. Probably only rich people would engage in such a scheme anyway.
    - Retr0id 2mo ago
      The whole premise here is cost optimization.
      - hobojojo 2mo ago
        It's not cost optimization its payment on installments.. Personally, I find it less convenient to have more than 1 bill and a group of 30 paying on average every 12 days probably makes it less convenient for anyone. But there are some strange consumers who like to delude themselves.

Apreche 2mo ago

Anyone who can afford to own a home can afford their batteries and doesn’t need gifts. Renters are not allowed to modify their home in such a way.

Tepix 2mo ago
In Germany you can use a "Balkonkraftwerk" that just plugs into any outlet and contributes up to 800W. You can also hook up solar panels to it up to 2000W (makes most sense with batteries). No need for the landlord to agree.

well_ackshually 2mo ago

>sixteen people contribute €100 each; yeah sure everyone has 100€ to spend on friends, at least once a month. What kind of reality does he live in ?

Hugsbox 2mo ago
You're getting downvoted, but for real this is so disconnected from what I'd say is feasible for most people. I and most of the people I know live squarely paycheck to paycheck, I can't afford to buy my friends birthday presents at all, let alone set aside that much per month just to put batteries in other peoples' houses. This feels like one of those things where the author doesn't grasp the privilege he lives with.
- Tepix 2mo ago
  Do they even have houses?
  - Hugsbox 2mo ago
    In some cases yes, and they're not doing much better than I am.
  - ssl-3 2mo ago
    Does having a home inherently change disposable income?
- Symbiote 2mo ago
  Even where people probably could afford it I think spending €100 on a birthday gift would be excessive. It would be showing off.
- Majestic121 2mo ago
  Surely not for _most_ people, but for people on Hacker News, in the correct age range to have a house, putting 100e aside really does not seem out of whack. Maybe the author is privileged and it's fine, it's not because you personally can't afford any gift that the author is disconnected, he might not just be talking to everyone on earth.

isoprophlex 2mo ago

> You are also safer during a power outage. The STREAM 5000 provides up to 3 kW of off-grid output. Keep essential devices on its backup output and reserve some battery capacity, and your refrigerator, lights, router, and laptop can keep running when the grid goes down. An ordinary grid connection does not back up the whole house automatically; the backup output must be configured correctly. Being able to cut over your entire house from grid power to a battery requires an invasive, expensive change to most connections. I wish people would stop breathlessly promoting batteries (which are good! we need decentralized storage!) because "you can use them to run your fridge, router, etc". Yes you can, but for almost all consumers it's an order of magnitude more effort and cash compared to just buying and plugging in a battery.

fhdkweig 2mo ago
If a fridge is your only concern, they make UPSes specifically for fridges. https://duckduckgo.com/?q=Uninterruptible+power+supply+refrigerator&ia=web https://duckduckgo.com/?q=Uninterruptible+power+supply+refri...
tonymet 2mo ago
I disagree. During an outage, you need your fridge and a few other essential items. A novice can plug into the back. The device tells you the load and whether you are exceeding. And you can test it at any time. For $600 you can get started without an electrician. it's the easiest, safest , most affordable and most reliable emergency solution ever available.
- brk 2mo ago
  For a relatively small battery like that, it's not going to last for days. In the typical outage where that battery would carry you, you can typically just leave the fridge closed and it will stay cold enough to prevent 99% of your stuff from spoiling. For most people (at least the US), it's not super easy to get at the plug in the back of the fridge anyway. Running HVAC is usually more of a concern, especially in winter or peak of summer, and those aren't device that you can hot-plug, and a small battery wouldn't help there anyway. I like the idea of whole-house batteries, but to really make it practical you're talking about thousands of dollars to the battery, install, etc. And you still don't have extensive run time, which is why I think you see most people still leaning towards permanent or portable generators way more than batteries.

or_am_i 2mo ago

How does 12 years required for this scheme to pay for itself stack up against the typical house battery's lifetime?

strbean 2mo ago
Sounds like that's roughly the average usable lifetime for the battery, so you will break even on average.
- deleted 2mo ago
  [deleted]
- Toutouxc 2mo ago
  Roughly the usable lifetime? Based on what?
  - medler 2mo ago
    The battery linked in the article (https://eu.ecoflow.com/products/stream-series-solar-battery https://eu.ecoflow.com/products/stream-series-solar-battery) advertises a 15 year lifespan and 10 year warranty. Personally I would expect batteries to last longer than that but 12 years feels fair
- hobo123 2mo ago
  I think most electric car batteries are still at over 80% capacity after 10 years usage, so hopefully you can use them much longer than that. If you only cycle then in the 20-80% range, they'll last much longer (at least for NMC cells, not sure how LFP works).
  - vel0city 2mo ago
    I'd imagine most electric car batteries aren't fully charging and discharging every day. That makes quite a bit of difference in wear! Tons of EVs these days are being made with what, 200-300mi range of battery pack with some internal buffer as well so they're never really going 0-100%? So what, we'll be generous here about the 20-80% and think 160mi of range used every day. That's 58,400mi of driving per car! The average US car does closer to 14,000mi. Being generous, that's 4x the wear cycles of a normal US automobile.

jerlam 2mo ago

> 2. Confirm that their home, meter, and electricity contract are compatible. This seems like the hardest step. The costs of "just a battery" are much lower by comparison.

jandrese 2mo ago
You don't necessarily need to export power, especially for a small battery like tihs. Charge it up when power is cheap, and then configure it to discharge when power is expensive but only to match your current usage. You will need a CT on your main feed for it to balance against, but it can be done.

archydeb 2mo ago

And if you’re in the UK, wire them up to Axle Energy (plug-in batteries aren’t actually legal here yet, but likely to become so next year!)

mindslight 2mo ago

Call me old fashioned, but I just bring a can of gasoline and a pile of super soakers. While I do like the idea in theory, I don't love the inherent nudge towards off the shelf productized energy storage that will be placed somewhere without much of a plan, and then basically invites rewiring with extension cords. I get how those things are appealing for camping or determined apartment DIYers at the like, but moving them from a seek-them-out "pull" dynamic to a here-you-go "push" dynamic seems like asking for problems from people not thinking too much about storing 5kWh.

Tepix 2mo ago

> €1,600 for 5 kWh Those prices are high. You can get 2.56kWh for 270€ on Aliexpress, delivered locally from Germany.

microtonal 2mo ago
2.56kWh for 270€ on Aliexpress What could possibly go wrong? The things that people do. Personally, I'd like the company to be in the EU so that I can at least sue them if it burns down the house.
markvdb 2mo ago
Most of these are illegal to install in Belgium though. Anything connected there needs national grid type approval.
pornel 2mo ago
> Aliexpress There are even cheaper ways of starting a fire.

jambalaya8 2mo ago

No.

thraway3837 2mo ago

You don't really need this, if you have an EV with V2X technology. There's already charging products that work seamlessly: https://www.youtube.com/watch?v=H0WGl_U5azs https://www.youtube.com/watch?v=H0WGl_U5azs and you have 100kWh of capacity, so you could sit out an outage for a long time. You can also configure the % cut off for the EV, so you still have enough left to drive if you need to leave. EV battery degradation from this use case is irrelevant. EVs are consistently hitting 300,000 miles with 90% capacity, so let's not belabor this point.

hypfer 2mo ago
> EV battery degradation from this use case is irrelevant. Nope.
adolph 2mo ago
The thing about the EcoFlow Stream is that has things like phase alignment which allows it to be plugged directly into a household outlet without transfer switches to segregate grid phase from the phase of power created by the V2X inverter's phase. It also handles solar input. I suppose that future V2X systems will incorporate direct plug-in tech, but note the transfer switch used by the system in the video.

ortusdux 2mo ago

This is what government subsidies/rebates are for - https://news.ycombinator.com/item?id=49298910 https://news.ycombinator.com/item?id=49298910 Gift should be ... gifts

sailfast 2mo ago

The 12 year payoff IF you manage the arbitrage properly really made me wonder why on earth you would buy one of these. I want one, yes. But it sure as hell wouldn't be to save money. It'd be to have something if and when the grid falls over due to negligence.

balderdash 2mo ago

11-13yr payback on something that is going to degrade ~3-4%/yr for 10 years (and limited terminal value) doesn't seem like the greatest investment unless you think the arb is going to widen a ton.

sdthjbvuiiijbb 2mo ago
And any arbitrage is also trivially exploited by the electricity company, who has a much greater financial incentive and scale, so there's really no reason to think that it's going to widen in the future either.
- bluGill 2mo ago
  You could exploit it yourself, but only if you have several million to invest, less than that and it isn't worth the bother for the electric company to talk to you. Even at ten million invested you really need to have this is round one in your proposal with the understanding you intend to invest a lot more when it proves in the real world to work like you expect.
- delecti 2mo ago
  Until grid-scale batteries are more established, you're helping the electric company, and that's why they're exposing the arbitrage. They're providing the incentives to nudge demand, so a home battery is doing exactly what they want (use more at time X, use less at time Y). Otherwise they'd just have the 24/7 price be whatever it currently costs when the supply and demand curves are tightest for them (when demand is highest and/or supply is lowest).
mosselman 2mo ago
Let's assume the calculation is correct and you actually earn back in 11-13 years. You are better off investing the money in something like the S&P 500 where you'd double your investment in about a decade without the hassle. Things will start to get interesting where €1600 don't buy you 5kWh but double or triple the amount. I can imagine most people are better off either investing like I said or in insulation.

scaredreally 2mo ago

At my mother's workplace, there was a group of coworkers who each donated an amount of money per paycheck. Each paycheck, one coworker would get the lump sum that was collected for that paycheck. Similar concept to the one described here. They called it "susu" or something to that effect. If I remember correctly, it got messy when people would leave the workplace or when, occasionally, someone would get robbed on the way home.

mtlynch 2mo ago
I read the book Poor Economics[0] around when it came out, and it described something similar. For people who don't have access to banks, they form "savings clubs" where there will be, say, 12 people who put in $100 per month, and one person takes the pot every month. The idea is that if you keep the money yourself, then you're socially pressured to spend it when there are holidays or guests, but if it's locked up in the savings club, you can't spend it, and then you get a big lump sum to spend on a large purchase that would be otherwise hard to save for. [0] https://en.wikipedia.org/wiki/Poor_Economics https://en.wikipedia.org/wiki/Poor_Economics

kortzeus 2mo ago

The only downside is that the battery won't last 11 years with daily usage

hypfer 2mo ago

A Marstek Venus A 2.12kWh expansion module currently costs 180€ with a bunch of special aliexpress discounts. The whole system is.. not great, but it's even cheaper to have a battery than this post makes it sound.

tristor 2mo ago

This is interesting, but is 3kW enough to be useful? What is the latest when it comes to home batteries? Has management gotten better to be smarter?

SubiculumCode 2mo ago

People don't tend to buy people large furniture because it's rude to assume that theyll want to keep something large and relatively permanent, much less something that requires an electrician to install.

vel0city 2mo ago

So I could buy a battery for ~$1,850 today that won't even break even in a decade (and hope everything goes well with this plan, not guaranteed in the slightest), or I can buy a 10 year US treasury note that'll give me another $1,000+ in profit at the end of the decade. Remind me why I should buy the battery? It clearly can't be because it makes financial sense to just have the battery.

mistivia 2mo ago

I don't think installing this kind of system at home is a good idea, especially considering the risk of fire. The amount of energy contained in a 5 kWh lithium battery is terrifing.

compiler-guy 2mo ago
There are numerous systems available for this type of system that are professionally designed and built, and satisfy all kinds of local codes. Many are in use all over the world in off-grid cabins and similar. You do need to take care that they are installed correctly, and maintained properly, but that isn't much different than a natural gas connection, or even normal everyday electricity.

hobo123 2mo ago

Strange article, even though the idea is nice. $200 birthday presents might be a thing in America in some circles, but for German standards that is ludicrous (even 50 bucks is quite a lot, and then you need 32 people). I also don't get his example calculation. He mentions that average price in Germany is 38c/kWh, but in the table it's suddenly 4c min vs 13c max (or 40 vs 133?). That doesn't compute.

skitsofrandom 2mo ago
[dead]

Johnny555 2mo ago

>thirty-two people contribute €50 each. I guess Europeans have more friends than Americans -- I can't think of 32 people I'd invite to a birthday party, and certainly not 32 people that I'd expect to give me a €50 gift. I haven't received a real birthday present from friends (beyond a cheap gag-gift) in decades.

chaostheory 2mo ago

As the post already mentioned, also great for blackouts, of which more are coming for the developed world given climate change and infrastructure failure

_ink_ 2mo ago

Germany is unfortunately not a good place to do this. The additional fees that you need to pay on top of the actual energy price are simply too high. And currently there is Katharina Reiche in charge which is actively fighting concepts like Energy Sharing.

imbusy111 2mo ago

The hybrid inverter that allows you to plug the battery into your house circuit (DC -> AC) seamlessly is around $2-3k + installation cost, cause you're touching the main panel. Why isn't that in the calculation?

domenkozar 2mo ago
You plug it into a socket.
- compiler-guy 2mo ago
  Plugging a power-supply into a normal outlet like this is legal in many places, and illegal in many others. Check local code before proceeding!

xur17 2mo ago

Do any US states allow plug in batteries like this (I know some allow plug in solar)? The installation cost of a whole home battery is what has kept me away so far.

daxelrod 2mo ago
That’s a good point. I had assumed the states allowing plug-in solar also allowed batteries, but according to https://pluginsolarguide.com https://pluginsolarguide.com , it’s only Utah so far.

rmykhajliw 2mo ago

Welcome to Ukraine where local people installed around 8GWt of batteries at home mostly because of huge outages after missile and ballistic terroristic attacks. Batteries installation is not about money , average LiFePo4 battery life is around 10 years, so you will save nothing, unless you have some local generation like solar panels. In this case you could shrink payback time to 5 years instead of 10 and it makes some sense. But the biggest problems here 2: 1. there a critical point after installing a huge amount of balance batteries the diff between day/night hours would be mitigated. And prices may down 30%. As result economical factor of installing energy storage systems would be very questionable. However cheap energy will increase energy usage by homes and industry and this may/might/probaly/i_hope. boost economy 2. The second factor riskier because when many people are installing energy storages and become independent of power grid, or even disconnects from the grid, there still exists power grid you have to support. Right now the price of grid support included in energy bill for electric company. The grid usage price is stable , it doesn't matter you support 1 person or a 1mln residents city. So the less people are using THE GRID - the higher prices for the rest people. And those high price forces rest people to disconnect from the grid. In general we may/I_hope_not to have situation with plenty energy islands and no more national grid systems

ivanjermakov 2mo ago

> keep essential devices running when the power goes out I guess it's very location-specific, but I haven't had a power outage longer than 1 minute in the past 5 years.

nancyminusone 2mo ago
You are correct. My area has had 3 in the past 5 months.

CGMthrowaway 2mo ago

How do I properly think about the fire hazard posed by a big battery in my house?

stogot 2mo ago

The example prices of kWH in this article are inconsistent

leemelone 2mo ago

how often do I have to buy a new one? Batteries are one of the highest cost and most consumable items I can think of.

cloudie78 2mo ago

[flagged]

xet7 2mo ago

It this ad from some battery company?

Tharre 2mo ago

There are two issues with the articles calculations, that end up making the already bad payback time even worse, before considering opportunity costs. Numbers are for Germany since that's the more favorable case: 1 - degradation: assuming the 15 years battery life / 10.000 cycles number from the datasheet is accurate, and that the manufacturer considers 70% capacity end-of-life, this pushes the payback time from 11.1 to 12.7 years. 2 - The article calculates the savings with: > daily saving = 4.5 × expensive price − 5 × cheap price but this is wrong because it assumes that grid charges fully cancel out. The article generally does a poor job at explaining this, but essentially it proposes you overbuy electricity when it's cheap and use it when it's expensive. The difference of those two, €0.133/kWh - €0.041/kWh is much smaller then the average electricity price of €0.3869/kWh because the latter also includes taxes and grid charges. So with 90% efficiency they end up with the formula above, but completely ignore the fact that from the grid's point of view, the total electricity consumption increased. On the flipside, it's also taking EPEX prices directly, pre-VAT, so you actually save 19% more then the difference 0.133 - 0.041 = 0.092. So the actual formula should be: > daily saving = 1.19 × (5×0.9 × expensive price − 5 × cheap price) − 5 × (1−0.9) × grid charges At a average rate of 21 cents/kWh for total grid costs (including VAT) that comes out to a payback time of 13.71 years. So yeah, buying batteries alone doesn't make sense. You need solar or wind to charge them, so you actually avoid the grid charges. So that instead of saving 10 cents you save 40.

ValentineC 2mo ago

How long do such batteries last? I remember having to replace the lead acid battery in my UPS every 2-3 years, which seemed like a waste of money considering my country's power grid is fairly stable apart from the occasional blackout from lightning strikes.

two_handfuls 2mo ago

A home battery you can just plug in. Interesting. Are those legal in the US?

turtlebits 2mo ago

I hate being a broken record, but batteries are $100/kWh now, sometimes less. Don't buy proprietary. You can get a 3kW inverter and 5kWh of battery for ~800 USD. Want more storage or output? Just add batteries or swap out the inverter.

radar1310 2mo ago

That’s the longest ad I’ve read in a longtime.

nc55g3g 2mo ago

[dead]