Tesla Powerwall 2

A lot of us are interested in off grid living, and batteries are a central component of that.

If you haven’t seen the latest announcement from Tesla, they are going to have solar roof tiles that look just like normal roofing. So your house looks nicer… meh, whatever.


More interesting, they’ve now doubled the size of their Powerwall battery bank, now called the Powerwall 2. For the same price. https://www.tesla.com/powerwall

That’s a 14 kWh battery for $5,500. Plus another grand installed.

To get 14 kWh usable power from lead-acid, you need a 30 kWh bank (50% usable)

Wholesale Solar has a 31 kWh bank for $3,820. Add an inverter (included with Powerwall) and you’re basically at a break-even point. And you’re still using lead-acid, which has plenty of drawbacks vs lithium.

It seems really strange to say this… I think lithium ion has just become… affordable.


Thats is quite interesting, this has been something of interest and Ive been doing a ton of research. In fact Im looking at possibly launching an EV bike company next year and producing our own batteries based on the 18650 Li-ion battery. This is the same cell Tesla is currently using and also most cordless powertools.

Even more interesting carbon produced from Hemp maybe the holy grail manufactures are looking for. Graphene is still being perfected for manufacture process but it is still not there yet to be commercially viable solution. Current Graphene cells have roughly 5x the energy density over current lithium cells. Carbon produced from Hemp has the potential to perform just as well but maybe easier to manufacture and produce. So this is something very interesting and this will be a major game changer for Tesla, other EV tech and for off grid systems.

Whether I create the bike that will surely happen at some point I want one!! We will see if I can find the right investors to make manufacture of them a reality. So that part will remain to be seen. But the battery for off grid with these cells will be at the forefront next year. Its really not all that difficult and most of you DIY guys can build this thing yourselves. Plenty of Youtube videos out there.

Here is the bike I want to manufacture this is not some wimpy EV bike this thing will scare you!!!


Here is a write up I did on the carbon based Hemp battery I did on our FB page. If you have more interest in this, look up Robert Murray Smith on Youtube. Much to be learned here!

This guy does a pretty good set of videos showing how to construct a DIY version of the PowerWall.

You can get batteries cheap if you can source them second hand. But you will have to test every one of them. One bad cell = one very bad head ache :fire:

I think graphene is a bit closer then you think. There are several companies working on them across the world. This one from China says graphene enhanched, and they haven’t given a release schedule or price but they did come up with a demonstration for a tech show.

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I hope both technologies come to market, I wish they were both here right now. I have a jar of graphene that I got from Amazon to experiment with.


Hi All
This leads to were is the “best” point to jump into technological changes?
Well “best” for Who? And Why?

Specifically. A known DOW member and I back in the 2009-10 era talked a lot about possible battery bank storage to use. Our talk then was about Edison cells. Actually available as transit take-outs; and new manufactured from China. One: half-life used up. The other; with indifferent manufacturing quality.
I concluded then just use a big-assed available electric forklift lead acid cell-pac. WAS using an old 1700 pound 12V lead-acid cell pac in an electric forklift in BenP’s VictoryGasworks Vancouver shop.
The other DOW member had a brother-in-law in fleet truck maintenance. He could get used take out truck lead acids for the hauling away.
And these now bank his rather large house roof PV solar. And then a DIY home wind turbine.
He then became infamous on the DOW as declaring that woodgasification for DIY fuel was a good way to use up old IC engines.

An interesting tech-change perspective is in personal use video and computer systems.
Wife just this morning plugged in and fired up her always kept in car, travel-to, 2001 Dell laptop to check this new months home client needs files. It had never seen the internet. XP Windows system. She doesn’t even bother to replace it’s aged out battery. NimH?
Her just two year old DELL office location laptop gets used daily for now needed Interneting with the State of Washington Dept of Health, is just coming out of the shop needing having it’s munched hard-drive replaced. So . . . a true hardware failure? Or a bugged destroy from her two Assistants internet shopping expeditions? This one got new, as a Windows 7 system, even though 2 years ago there were “newer”, “better” available systems - THAT WERE NOT! Better. Just newer. More profit for Bill Gates and gang.
Windows 10 now the new darling, must-have, must-get.
Also just yesterday I sat with the wife through pre-surgery, post-op recovery phases. She was very “wired-up” monitored. All the late 2016 hospital equipment not dedicated propitiatory, was Windows 7 based.

The best bet for the common guy/gal is to use three generations back Tech; bought new; being sold down then to move it out.
I just replaced the made in 2001 Sony Trinatron 27" CRT living room TV with a Sharp brand 43" LED TV.
Waiting 18 months, two years in both cases for the early adopters to de-bug and then impatiently move on to newer hyped butterflies really saves on the real-use costs and failures hassles.
Oh yeah. This Sharp TV is a 4K, capable set. Only $400. USD.
Now got a replacement vid player to match. Sony Blue-Ray player capable of up through 4K and 3D. Backward compatible for nearly all other previous disc formats. A big-box retailer stripper features machine. $79, USD.

“All good things come to him who waits”
Tesla cells, graphene cells I would use too.
After the early adopters bear the costs to refine them and make them common, proven trusted, and affordable.

Steve Unruh.


They are coming. It is hard to get from the lab to a scalable, low cost industrial process which is probably where most folks are getting stuck. The graphene aerogels are a hot area of research right now. It is the lightest substance known, it is electrically conductive, strong, and retains it shape after compression, etc.

Steve is right, they aren’t going to be cheap for a while, it takes time to recover the r&d costs and manufacturing costs. However, with all the patents being filed now, the expiration of those patents, opens up the market to anyone to manufacture in like 20 years which brings for some very interesting scenarios especially when you are looking at people wanting to build out the existing FF infrastructure, and the facilities need 30-50 years of depreciation to be cost effective.

Here is an article about a Korean company. but there are several others across the globe. The method doesn’t sound that complex:


I guess that was my point about the lithium. For a long time it’s been a small quantity, early-adopter tech. Now, we seem to be way down the price curve. This might be the time to jump in, while you wait for more magical battery tech to come along.


I just purchased/installed 8 l16 sized approx 12 months old from someone who changed their mind about off grid. Rated at 530 amps over 50 hours 400 over 15 hours for $165 canadian a piece. In theory this gives me 12 kw of use able power ( more if I want to dip below the 50 percent range). My hope is this is my last set of lead acids and that the magical better battery promised for over 20 years will arrive this time. I like the new salt batteries from aquion myself. I’m waiting for the price to drop but they seem very interesting.


Yes ChrisKY
I actually did hate being the go-slow “nay-sayer” about the new hyped Lithium tech banks.
I’m typing on the lithium battery laptop you and the guys gifted to me right now.
Got a lithium battery cell phone in my breast pocket too.

But . . . two cell phones back, 2003-05?, I had to take back that Samsung because recharging it just got too damn scary hot after the third week.
The most reliable successful hybid vehicle in the world is the Toyota Prius and they still will not use LiOn cells.
The early deployed Boeing Dreamliner LiOn battery bank fires were real. Cell/bank manufacturing defects? Charge systems going berserk? Still in litigation, I think.
This newest Samsung smart phone recall for battery overheating. People been injured and hurt.
The many laptop recalls.
Lithium ion cells are charge tricky, and much more sensitive than previous cell tech’s.

Tesla’s still a relatively new company still out to make a name for themselves.

Sorry. I still see thier blast-out promotions as more trolling for more investment dollars.
As SeanO very accurately said it takes millions in R&D. Then years/generations of manufacturing deployment to refine a new tech into stable use.
Older line established companies can to self-fiance and absorb this. Admittedly at a much slower development out rate. And they STILL have roll-out deployment flop/failures.
New start companies/endeavors are a slave to generating new money in. With that new-money going out fast.
Much. Much. Higher failures to please rates, on user services and products.

Ancient history, but I dragged along slow and did not buy the truly better fidelity Betamax way back when. Did not buy into the big video hard disc system systems from that era either. Every VHS tape I have from then can still be played and viewed.
And our 1994 era Motorola digetal Nickel-Metal Hydride 1.5 Ah flip phone will still power up and try. AT&T stopped supporting that protocol.

And I’ll admit to having a lifetime of at least five lead-acid battery blow ups. That would be ~1 in 10,000 used and serviced. My personal lithium cell use failure rates is higher than 1 in 10. NiMdHy failures - zero failures out of hundreds personally used now. Just too many cycles, wear-outs.

Once you start working with power cell arrays measured in 10’s, and 100’s of killowatt hours and greater, when bad things happen. They happen very BAD. Hellava’ lot of energy release.
Took literally decades to evolve gasoline handling systems to safe enough for the very rare then unintentional energy releases to be just be a s-t-o-o-p-i-d’s, bypassed too many safety steps rare “accidents”.

Steve Unruh


This was pointed out to me recently " as a side note I don’t think Tesla is using Lithium Ion Cobalt Oxide for stationary use but rather Lithium Ion Manganese Nickel Cobalt Oxide which has different characteristics."

So less blow up potential but still that small package has to deliver one he’ll of a punch repeatedly, perfectly for thousands of charge cycles, the charge circuitry has to work perfectly, the on board cooling system has to work perfectly It’s probably my primitive brain but I equate lead’s mass as stability and with the idea that mistakes happen slowly. I guess I’m a dinausaur at 47…
Best regards David Baillie


One thing you have to understand, with any lithium cell; is there are many manufactures. Lithium is now 30 years old, well proven and manufacturing now established. Your cell phone or laptop is simply not a good comparison to the rolled 18650 cell. There are many flavors of this cell and none have the exact same chemistry. Samsung vs Panasonic vs cheap chinese brands. Your dewalt cordless drill and others alike is a better comparison and you can see how well the different types work against one another. Dewalt vs a Harbor Frieght for example. You get what you pay for.

For me as manufacture trying to take gasification to the next level of bullet proof and providing a machine that can be as practical as a liquid fuel machine is a challenge and I have my work cut out for me. At the same time I can not be afraid of adopting new technology. What we do is renewed technology and with out improved battery storage advanced electronics/automation, etc. we go nowhere. If we are to lead the way we must do things differently. Most on here are ok with fiddling with valves. shutting down the machine for maintenance and all that goes with gasification. This is not the case for us and the markets we are dealing with. They only want to put fuel in the machine and this absolutely it and nothing more except for a monthly servicing. So yeah next year Im going to be busy, I have the automation proofed out on the bench for full automatic run modes.Then I have two more pieces of technology to work on, the duel reactor systems that will have other support systems to make it work and then the micron regen filter to make it bullet proof and also allow to offer the engine manufactures warranties. If we can create the micron filter the engine manufactures are willing to certify us. Battery storage is the only way to make the systems practical and efficient and current battery tech other than Lithium is a very hard sell.


So Matt out of curiosity is it lithium ability to charge fast that’s the key for you? Bigger gassifier unit shorter runs more time between runs? I see that as lead acids big problem the c10 charge rate.


Ultimately yes and even further down the road we want to scrap the ICE and go to SOFC this is the real reason I purchased the graphene. I envision the fuel cell incorporated directly in to the gasification process.

I also want to add is charge cycle and size of the storage device. What you have there in lead acid can be accomplished in a package the size of a couple brief cases with a cycle life of 500 to 700 cycles.


Ive been thinking about building a PVC tube cell. It would seem to be much easier to construct. Put the cells in like flash light with end caps and then hook a bunch in series to get the desired voltage. 48 volts is really the only way to go until we can find even higher input inverters.

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We are drifting here a little but have you thought of using the board end of an inverter generator? They are supposed to be running at a higher dc voltage then 48 volts… just a thought…

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If I could find them commercially available “off the shelf” it would be a solution for sure

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Look. This is really very, very simple.
D.B. at 47 years has now decades seen his share of over-hyped, just around the corner, Tomorrow systems.
I am now turning 64 years old. Two MORE decades of over-hyped fuel-cells and such, that still ain’t here. And if/when come a Just-Tomorrow’s tech that comes into general use I would not touch until 10 years in world-wide services proven.
Some may wish to remain addicted to Popular Science, Popular Mechanics, Popular Electronics magazines over-hyped Worlds of Tomorrow. Not me. Grew up, and gave up that stuff by my late 20’s.

Here is what is real, now, today, usable past lead-acids.
The now evolved Nickel-Metal Hydrid cells. These are now developed as low, low self-discharging. With much reduced memory characteristics. Much safer recharge characteristics versus any lithium type cell.
Advanced NiMH are what Toyota uses in their Prius and other hybrid vehicles.
These are no longer 1980’s limited.

Advanced NiMH available now as AAA, AA, and D replacement cells. You will know the newer developed ones as packaged as pre-charged, and low discharge characteristics.
Every month I buget buy a few more pacs of Rayovac Pre-Charge Plus 900mAh, AAA cells. A few more pacs of EverReady Energizer 1500 mAh, AA cells.
I passed on the only 2000 mAh D cells from EverReady. Passed on the capabilities edge-treading specialty brands 8000 mAh, D cells. Buy from Battries-Plus pacs of Nuon brand middle-of-the-road 3000 mAh, D cells.
Yes. Yes. ALL made in China. Why you have to stick with brands, distributors who will care about quality control and returns rates.
Everything here now: headlamps, wireless remote controls, lanterns, flashlights, radios, ect, is getting changed out to these evolved NiMH’s now.

If I wanted to step up right now past lead-acid banks I would be going to hybrid car take-outs cell banks. Or, assemble my own banks from better 6000 mAh, D cells.
Yep. You will be into over 150 to 300 volt DC hairy-scary banks to get the toatal AH capacity. Have to learn charging banks like these. Feeding into existing inverters for your AC consumers usages.
All Today tech, now, proven, available.
That is what my now two Honda and Yamaha inverter-gnerators are about.
Teach ME the details

Regards - still alive, learning, and doing
Steve Unruh