Tesla Powerwalls Exposed To Password Hacks Via Google

[Cerebus]

People should NOT be posting vague, unsubstantiated claims about the US grid being taken down by hackers and a computer virus.  Don’t you agree they shouldn’t be doing this?

[Bud]

Tell this to your crooked mass media.

[SilverSolder]

[...] Powerwall is about 11.5k for 13.5kWh. [...]
 The quote I got was 13K for one and 25K for two(with tax).

So one Powerwall has similar capacity to 5x 200Ah 12V lead acid batteries, costing < $400 each or < $2,000 total.  Then you'd need an inverter etc.

[maginnovision]

Yea, even with an inverter the cost is less. I've already built backup systems for people before.  Even after paying me they paid less for more. I'm not going to argue... If you like powerwalls then buy them.

[wraper]

Powerwall itself costs $7k for 13.5 kWh with 7kW peak and 5kW continuous power, contains charger and inverter, so you have a fair comparison. That price quote is for a fully installed system with all permits, inspections and whatnot. And is on the high side, so it may have something to do with your location or something like that. DIY battery will be illegal and of dubious safety. Don't forget it contains tremendous amount of energy and can burn down your house easily, if something goes wrong. And your insurance company will tell you to screw yourself.

[sandalcandal]

Powerwall itself costs $7k for 13.5 kWh with 7kW peak and 5kW continuous power, contains charger and inverter, so you have a fair comparison. That price quote is for a fully installed system with all permits, inspections and whatnot. And is on the high side, so it may have something to do with your location or something like that. DIY battery will be illegal and of dubious safety. Don't forget it contains tremendous amount of energy and can burn down your house easily, if something goes wrong. And your insurance company will tell you to screw yourself.

Design/installation safety plus various stamp duties aside, I'm interested in if it's a fundamentally better cost-utility choice based on technology rather than implemention.

[...] Powerwall is about 11.5k for 13.5kWh. [...]
 The quote I got was 13K for one and 25K for two(with tax).

So one Powerwall has similar capacity to 5x 200Ah 12V lead acid batteries, costing < $400 each or < $2,000 total.  Then you'd need an inverter etc.

Yea, even with an inverter the cost is less. I've already built backup systems for people before.  Even after paying me they paid less for more. I'm not going to argue... If you like powerwalls then buy them.

So your equivalent but cheaper system uses lead acid batteries (deep cycle AGM I presume?) with an equal 100% DoD capacity? If you intend to use it only a handful of times per year to stop the lights going out and just have them on float the rest of the time as a UPS then I guess that's fit for purpose but I can't see that being a better lifetime (or even upfront) cost if the batteries are actively being used daily to provide off-peak on-peak balancing and solar energy storage to actually help grid stability or cut down your electricity bill.

Can I ask how your systems are holding up long term?

[RenThraysk]

Try #2, lost first post attempt.

Bit embarrassing.
Hopefully serious companies will start using zero trust architectures.
There is no reason why every device on the internet should be able to contact, let alone being able submit a login request to your powerwall.

ZeroTier and Tailscale are two companies provided products that aim to solve this problem, without the burden and hassle of outdated methods.

[maginnovision]

Powerwall itself costs $7k for 13.5 kWh with 7kW peak and 5kW continuous power, contains charger and inverter, so you have a fair comparison. That price quote is for a fully installed system with all permits, inspections and whatnot. And is on the high side, so it may have something to do with your location or something like that. DIY battery will be illegal and of dubious safety. Don't forget it contains tremendous amount of energy and can burn down your house easily, if something goes wrong. And your insurance company will tell you to screw yourself.

Design/installation safety plus various stamp duties aside, I'm interested in if it's a fundamentally better cost-utility choice based on technology rather than implemention.

[...] Powerwall is about 11.5k for 13.5kWh. [...]
 The quote I got was 13K for one and 25K for two(with tax).

So one Powerwall has similar capacity to 5x 200Ah 12V lead acid batteries, costing < $400 each or < $2,000 total.  Then you'd need an inverter etc.

Yea, even with an inverter the cost is less. I've already built backup systems for people before.  Even after paying me they paid less for more. I'm not going to argue... If you like powerwalls then buy them.

So your equivalent but cheaper system uses lead acid batteries (deep cycle AGM I presume?) with an equal 100% DoD capacity? If you intend to use it only a handful of times per year to stop the lights going out and just have them on float the rest of the time as a UPS then I guess that's fit for purpose but I can't see that being a better lifetime (or even upfront) cost if the batteries are actively being used daily to provide off-peak on-peak balancing and solar energy storage to actually help grid stability or cut down your electricity bill.

Can I ask how your systems are holding up long term?

No, I don't use lead acid batteries. I use different batteries for different builds. Lithium ion and lithium polymer (polymer pouch cells are cheaper and better density but I only use them for temp controlled installs) along with lithium iron phosphate for people who want the best long term solutions(also becoming best overall anyway). They have all the expected safety features as well.

As far as lifetime the oldest installs are only ~5 years old. No issues but I wouldn't say it's been long enough to say what the performance really is compared to powerwall 2's claims(don't forget the original "powerwall" was pretty poor and hard not to beat). Compared to initial specs, and 5 year performance they're outperforming powerwall 2 in initial cost, and kWh/$ and they're on track for that to continue barring any failures. What Tesla has is a fancy package(the work is contracted out) where I use cabinets which can be painted any color. At this point I haven't built or installed one in about a year but the only thing that has changed is prices have gone down.

[sandalcandal]

Sorry, this is getting a bit off-topic.

No, I don't use lead acid batteries. I use different batteries for different builds. Lithium ion and lithium polymer (polymer pouch cells are cheaper and better density but I only use them for temp controlled installs) along with lithium iron phosphate for people who want the best long term solutions(also becoming best overall anyway). They have all the expected safety features as well.

As far as lifetime the oldest installs are only ~5 years old. No issues but I wouldn't say it's been long enough to say what the performance really is compared to powerwall 2's claims(don't forget the original "powerwall" was pretty poor and hard not to beat). Compared to initial specs, and 5 year performance they're outperforming powerwall 2 in initial cost, and kWh/$ and they're on track for that to continue barring any failures. What Tesla has is a fancy package(the work is contracted out) where I use cabinets which can be painted any color. At this point I haven't built or installed one in about a year but the only thing that has changed is prices have gone down.

So you reduce costs by sourcing your own cells, building your own packs (and BMS systems?), using off-the-shelf cabinets and providing your own labour?

Let me estimate the costs of that compared to a Tesla Powerwall at 7000/14=500 $US/kWh and tell me if I'm making any errors.
For small qty. commercial or DIY initial cost for cells alone is at best 300 $US/kWh (most are closer to 400 $US/kWh) though I've seen some questionable looking Chinese import cells as low as ~200 $US/kWh. For assembled packs including BMS: a quality USA domestic assembled pack costs 740 $US/kWh but "known" quality Chinese are 400 $US/kWh. In a best case you've got 200 $US/kWh saving compared to the full cost of a powerwall but more likely you have only 100 $US/kWh and if you really want an "expensive" option you'll be losing 240 $/kWh already. So with 14 kWh of cells alone you have at best $US 2800 to come up with BMS, 5kW inverter and enclosure. If you're using pouch cells you need to have additional mechanical components for clamping the pouches properly.

Edit2: Salvaged/Surplus/2nd hand cells are another option which can go down to ~100 $US/kWh but are very subject to availability and have added risks with warranties, liabilities and some extent safety depending on the source.

Cheapest "known" 5kW (pure sine) inverter on Amazon is $US 550 (I've had issues testing an inverter from this brand in a prototype system), a "cheap" made in China inverter from a US company is $US1299 and a quality 5kVA inverter is $US 2540 So with the inverter included you're now $US 1500 left for the rest of the system or nearly completely out if you want to go with the high-end solution.

Other components are relatively low cost: ~$US200 for the cabinet, ~$US150 BMS and then a bit extra for cables, fuses, connectors etc. Best case, you'd be saving $US 1000 on a $US 7000 component and you're putting together your own using low-tier, made-in-china parts, at cost, with your own labour free instead of buying a complete, ready-to-go, made in the US system with a 10yr warranty and commercial support. Its not even like you can't just buy the Powerwall as a component and install it yourself (at least in Australia) https://www.ecoelectric.com.au/shop/tesla-powerwall-tesla-14kwh-battery.html

Edit: All of the listed inverters apart from the last $US 2540 Victron don't have chargers, grid-tie or standards certifications like the Powerwall. A made in Taiwan, UL listed, 6kW inverter charger from a US company costs $US 2011 but still doesn't have grid tie. That'd make it $US 500 saving best case but should really be more like losing $200 if actually comparing to the functionally equivalent Victron that does grid-tie and charging.

Yea, even with an inverter the cost is less. I've already built backup systems for people before.  Even after paying me they paid less for more.[...]

I'd really like to know what you're doing to achieve that.

[DougSpindler]

I’m not an expert but your figures are reasonable.  And if one just thinks about it with a DIY you are going to pay “retail prices” for the components when you build one or two, so the only savings would be in the labor to design, assemble and test.  And you are correct, there is no warranty or guarantee the thing a DIY built won’t disappear in a puff a smoke or worse, spontaneously combust and create a nice fire as we have seen happen with cell phone and computer laptop batteries.  Heck we’ve even seen Tesla cars in accidents be destroyed from electrical fires after an accident.

[SilverSolder]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

Of course there are risks with this, but there are also risks with having 1,000 gallon heating oil tanks in your basement...   or an oxy-acetylene torch set in the garage...  etc.

[wraper]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

Of course there are risks with this, but there are also risks with having 1,000 gallon heating oil tanks in your basement...   or an oxy-acetylene torch set in the garage...  etc.

But it's relatively inefficient and will not last long. Good luck with achieving 5000+ charge cycles, 90% round trip efficiency and 10+ years lifetime out of lead-acid battery.

[SilverSolder]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

Of course there are risks with this, but there are also risks with having 1,000 gallon heating oil tanks in your basement...   or an oxy-acetylene torch set in the garage...  etc.

But it's relatively inefficient and will not last long. Good luck with achieving 5000+ charge cycles, 90% round trip efficiency and 10+ years lifetime out of lead-acid battery.

Absolutely true.  But there are some light-duty use cases where this works fine, for example for back-up power in case of outages.

[sandalcandal]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

Of course there are risks with this, but there are also risks with having 1,000 gallon heating oil tanks in your basement...   or an oxy-acetylene torch set in the garage...  etc.

But it's relatively inefficient and will not last long. Good luck with achieving 5000+ charge cycles, 90% round trip efficiency and 10+ years lifetime out of lead-acid battery.

Absolutely true.  But there are some light-duty use cases where this works fine, for example for back-up power in case of outages.

I also already said lead acid might be fine for a UPS, backup type system but Powerwalls are for solar storage and on-peak off-peak levelling so its not really an equivalent comparison; particularly for lifetime cost.

[DougSpindler]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

Of course there are risks with this, but there are also risks with having 1,000 gallon heating oil tanks in your basement...   or an oxy-acetylene torch set in the garage...  etc.

But it's relatively inefficient and will not last long. Good luck with achieving 5000+ charge cycles, 90% round trip efficiency and 10+ years lifetime out of lead-acid battery.

Absolutely true.  But there are some light-duty use cases where this works fine, for example for back-up power in case of outages.

How is back-up power in case of an outage considered light duty?  With most outages lasting hours to days how it that light duty?  Light duty would be powering a few LEDs. 

[SilverSolder]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

Of course there are risks with this, but there are also risks with having 1,000 gallon heating oil tanks in your basement...   or an oxy-acetylene torch set in the garage...  etc.

But it's relatively inefficient and will not last long. Good luck with achieving 5000+ charge cycles, 90% round trip efficiency and 10+ years lifetime out of lead-acid battery.

Absolutely true.  But there are some light-duty use cases where this works fine, for example for back-up power in case of outages.

How is back-up power in case of an outage considered light duty?  With most outages lasting hours to days how it that light duty?  Light duty would be powering a few LEDs.

"Light duty" is obviously subjective, but that's what I would call running a fridge and a couple of lamps,  less than 500W, for max 12 hours.

[madires]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

... when you get them for nearly free. The standard types don't survive much cycles and the types optimized for PV with more cycles are expensive. Li-Ion provides a real alternative.

[SilverSolder]

If you are going to DIY, lead-acid makes sense:  low cost, easily available.

... when you get them for nearly free. The standard types don't survive much cycles and the types optimized for PV with more cycles are expensive. Li-Ion provides a real alternative.

Nobody is disputing that Li-Ion has better cycle life etc., but it is also significantly more expensive than Pb-Acid - so, if you don't need the cycle life...   why buy more than you need?

A 200Ah, 12V battery can be yours for less than $400, without searching very hard.  Just one of those can run a fridge for 12 hours...

People have been using this technology in recreational vehicles for decades - it is mature technology.

[NiHaoMike]

For small qty. commercial or DIY initial cost for cells alone is at best 300 $US/kWh (most are closer to 400 $US/kWh) though I've seen some questionable looking Chinese import cells as low as ~200 $US/kWh. For assembled packs including BMS: a quality USA domestic assembled pack costs 740 $US/kWh but "known" quality Chinese are 400 $US/kWh. In a best case you've got 200 $US/kWh saving compared to the full cost of a powerwall but more likely you have only 100 $US/kWh and if you really want an "expensive" option you'll be losing 240 $/kWh already. So with 14 kWh of cells alone you have at best $US 2800 to come up with BMS, 5kW inverter and enclosure. If you're using pouch cells you need to have additional mechanical components for clamping the pouches properly.

Good quality batteries are available for less than $120/kWh.
https://batteryhookup.com/

For the inverter, hack a Prius inverter and you'll get something that can easily handle 10-20kW continuous and well over 50kW peak.

The BMS is not that difficult to DIY, a string of microcontrollers with optoisolators to cascade the serial communication would probably be the easy option that doesn't require hard to find ASICs.

[wraper]

For small qty. commercial or DIY initial cost for cells alone is at best 300 $US/kWh (most are closer to 400 $US/kWh) though I've seen some questionable looking Chinese import cells as low as ~200 $US/kWh. For assembled packs including BMS: a quality USA domestic assembled pack costs 740 $US/kWh but "known" quality Chinese are 400 $US/kWh. In a best case you've got 200 $US/kWh saving compared to the full cost of a powerwall but more likely you have only 100 $US/kWh and if you really want an "expensive" option you'll be losing 240 $/kWh already. So with 14 kWh of cells alone you have at best $US 2800 to come up with BMS, 5kW inverter and enclosure. If you're using pouch cells you need to have additional mechanical components for clamping the pouches properly.

Good quality batteries are available for less than $120/kWh.
https://batteryhookup.com/

For the inverter, hack a Prius inverter and you'll get something that can easily handle 10-20kW continuous and well over 50kW peak.

The BMS is not that difficult to DIY, a string of microcontrollers with optoisolators to cascade the serial communication would probably be the easy option that doesn't require hard to find ASICs.

I only see used batteries at such price.

[sandalcandal]

For small qty. commercial or DIY initial cost for cells alone is at best 300 $US/kWh (most are closer to 400 $US/kWh) though I've seen some questionable looking Chinese import cells as low as ~200 $US/kWh. For assembled packs including BMS: a quality USA domestic assembled pack costs 740 $US/kWh but "known" quality Chinese are 400 $US/kWh. In a best case you've got 200 $US/kWh saving compared to the full cost of a powerwall but more likely you have only 100 $US/kWh and if you really want an "expensive" option you'll be losing 240 $/kWh already. So with 14 kWh of cells alone you have at best $US 2800 to come up with BMS, 5kW inverter and enclosure. If you're using pouch cells you need to have additional mechanical components for clamping the pouches properly.

Good quality batteries are available for less than $120/kWh.
https://batteryhookup.com/

For the inverter, hack a Prius inverter and you'll get something that can easily handle 10-20kW continuous and well over 50kW peak.

The BMS is not that difficult to DIY, a string of microcontrollers with optoisolators to cascade the serial communication would probably be the easy option that doesn't require hard to find ASICs.

I only see used batteries at such price.

Batteryhookup.com is salvaged (and tested), used, surplus and NoS batteries. Popped into my mind last night as another option actually.

Salvage/2nd-hand is a viable option for DIY and small business (for now) which you'll never be able to get from a tier 1 commercial manufacturer. Obviously there are downsides like liability, warranties and uncertain availability but I think there are people willing to accept those risks for a dirt cheap storage system. I'd hesitate to sell it as equivalent to a commercial off the shelf solution though.

Availability is a big issue when trying to use salvage/surplus/2nd-hand (SSS?) cells. Every time a Leaf gets written off in Australia there's a pretty mad scramble to try grab the battery pack. Your only chance is having inside connections at the wreckers to get in before everyone else. Builds using salvage/surplus/2nd-hand cells are more opportunistic than something you can build a stable business around.