# DIY Tesla Power Wall for Cheap - $600.



## GTGallop

I'm stoked about Elon's power wall. Right now it's at $3,000 to $3,500 depending on what model you get and that doesn't cover installation and getting permission from your local government and power provider. But the more these get bought and used, the cheaper they become and the more pressure is on local government to accept them.

One of the things, as we capitalists know, that drives cost down and quality up is competition. Right now, Elon doesn't really have any competition. Except maybe this guy!






He claims it is a $300 power wall but it is also half the power - so you need two, or $600.

But for a minimal electrical use cabin situation, that 4.4Kw battery may be more than enough to keep the lights on, and not just the ones inside, but security lights and motion detectors outside, as well as microwaves and other modern conveniences like a CPAP machine. It is CERTAINLY enough to run your coms, especially if you run a 12v tap off of it to go straight into the radio. You could even scale this way back for a portable unit next to your tent if you are going lean and mean.

See if it tickles your fancy. He has a lot of great videos to baby step you through this.


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## Atilla

This is bad ass. I've been running a wheelchair battery outside everyday to see if a solar cell will keep it charged enough to charge all my low voltage stuff (12 volt battery charger, radios, and of course USB for phones, pads, etc). I've been thinking of a good way to put the panel on the roof and make a cubby hole between two studs to store the electronics and a battery.

I wanted this technology:

https://en.wikipedia.org/wiki/Nickel–iron_battery But you have to order them $7,000 at a time or so.

This would be a perfect alternative. I'm also a computer tech and have all kinds of laptop batteries around. Great find. Thanks.


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## essdub

Excellent. Another project. Like I needed another project. Lol. Not sure how I've never thought of this, but I'm glad these particular wheels are turning now


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## Mosinator762x54r

Wow...This guy rocked it. And imagine how cheap Tesla is getting all of their materials. No wonder Elon is a billionair. LOL. 

Awesome video. Awesome project. Solar is something I want to do and that is something I definitely will look into DIY'ing when I get into the solar.


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## Will2

I'm wondering two things.

How many cells are still usable in used laptop batteries as he suggested. IE what will it really cost and 2. how much the cell materials cost as there were some materials like the fuses that he didn't mention

None the less very interesting. It is definitely an interesting project to start with seeing how much it costs to make a 12v cell. Personally of all batteries lithium is the one I am most afraid of due to the fact it could explode or start on fire. Cells are pretty normal though, its just the lithium itself that is a little scary.

Take for example this lot of 20 laptop batteries is selling for $125 US plus shipping 20X Dell T54FJ Lithium ION Laptop Battery Compatible With Latitude E5430 E5530 | eBay

how much toward that project would you get, that is about $7 per battery. These are 6 cell batteries so that is about $1.30 us per cell. This would mean that for 600 cells it would run closer to $700 however I am guessing he must be buying them a lot cheaper than this one.


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## Atilla

Will2 said:


> I'm wondering two things.
> 
> How many cells are still usable in used laptop batteries as he suggested. IE what will it really cost and 2. how much the cell materials cost as there were some materials like the fuses that he didn't mention
> 
> None the less very interesting. It is definitely an interesting project to start with seeing how much it costs to make a 12v cell. Personally of all batteries lithium is the one I am most afraid of due to the fact it could explode or start on fire. Cells are pretty normal though, its just the lithium itself that is a little scary.
> 
> Take for example this lot of 20 laptop batteries is selling for $125 US plus shipping 20X Dell T54FJ Lithium ION Laptop Battery Compatible With Latitude E5430 E5530 | eBay
> 
> how much toward that project would you get, that is about $7 per battery. These are 6 cell batteries so that is about $1.30 us per cell. This would mean that for 600 cells it would run closer to $700 however I am guessing he must be buying them a lot cheaper than this one.


I've been researching this pretty heavy and $300 is a pipe dream if you are trying to buy them on eBay at current asking price. I took apart 4-5 packs (total of 26 cells) and so far have 3 with no voltage, 4 measuring under 2V, 12 measuring 2-2.99V, and 8 measure 3V or more. I just ordered a couple of better Li-ion battery chargers to play with. I have one of the <2V on a simple hobby charger to see what it will do. Two of the ones that tested 3 volts and charged for a bit went to 4 volts, but I was using a meter designed for household wiring, not electronics. I've now sorted them using a more accurate meter. I'm not discouraged, but you need to raid the local merchant's "Recycle Your Batteries Here" box to make this cheap. It's also a lot of work to salvage them. I found breaking them over my knee like piece of kindling works well, but there is still a lot of tape etc to remove to get a clean cell.

I'll know more as I try to charge individual cells. I also have better packs to try. These first few are from my known bad pile.


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## Will2

Atilla said:


> I've been researching this pretty heavy and $300 is a pipe dream if you are trying to buy them on eBay at current asking price. I took apart 4-5 packs (total of 26 cells) and so far have 3 with no voltage, 4 measuring under 2V, 12 measuring 2-2.99V, and 8 measure 3V or more. I just ordered a couple of better Li-ion battery chargers to play with. I have one of the <2V on a simple hobby charger to see what it will do. Two of the ones that tested 3 volts and charged for a bit went to 4 volts, but I was using a meter designed for household wiring, not electronics. I've now sorted them using a more accurate meter. I'm not discouraged, but you need to raid the local merchant's "Recycle Your Batteries Here" box to make this cheap. It's also a lot of work to salvage them. I found breaking them over my knee like piece of kindling works well, but there is still a lot of tape etc to remove to get a clean cell.
> 
> I'll know more as I try to charge individual cells. I also have better packs to try. These first few are from my known bad pile.


Good luck with that just be careful those things can pop if you charge them the wrong way. I'm guessing you know a little about them already though.

I will be trying to salvage some cells to fix my rather expensive cfc1 batteries, that may have bad cells. Hoping I can just swap them with known good cells. Need to figure out voltage on them.


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## essdub

To me, it sounds great to do this as cheap as the man claimed, but the more important issue is that I can do this a little at a time. Even if I buy all new batteries, if I only spend a couple or a hundred bucks at a time, I can increase the size of this Giant battery I'll be building until I have something that's actually useful. Until then, I'm trying to figure out a way to make each individual group of cells (which could all be wired parallel) removable to power lights or what not. A dozen of these 18650 batteries(many more and it wouldn't be as portable) will power a few of those really bright led head lamps for quite a while (I'm thinking minimal use of lighting during power outage or while camping, etc.) A little tweaking and could probably have a portable solar charger for this small battery (the dozen cells together)


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## 8301

some 18650 batteries come without the internal safe charging chip built in, others do. You need the more expensive current regulating chip built in batteries to avoid overheating (potential fire) when charging and discharging.

From what I understand Tesla currently uses the Panasonic Orbtronic 18650 batteries in both it's cars and Powerwall with their built in current regulating chip.


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## GTGallop

Will2 said:


> I'm wondering two things.
> 
> How many cells are still usable in used laptop batteries as he suggested. IE what will it really cost and 2. how much the cell materials cost as there were some materials like the fuses that he didn't mention
> 
> None the less very interesting. It is definitely an interesting project to start with seeing how much it costs to make a 12v cell. Personally of all batteries lithium is the one I am most afraid of due to the fact it could explode or start on fire. Cells are pretty normal though, its just the lithium itself that is a little scary.
> 
> Take for example this lot of 20 laptop batteries is selling for $125 US plus shipping 20X Dell T54FJ Lithium ION Laptop Battery Compatible With Latitude E5430 E5530 | eBay
> 
> how much toward that project would you get, that is about $7 per battery. These are 6 cell batteries so that is about $1.30 us per cell. This would mean that for 600 cells it would run closer to $700 however I am guessing he must be buying them a lot cheaper than this one.


There is some nuance in how he explained that. Basically you have to go back and watch two prior videos that he linked via picture in picture, but the short and simple is that he buys dead laptop batteries and usually it is only one cell that failed - the rest are still viable. He has a lot of labor and equipment tied up in testing and separating the wheat from the chaff. That never factors in to his final. But in the end he gets to $300 by what he spent and how many viable cells he ended up with.

What he doesn't outline is that these are all heavily used cells and may have less than 50% of their life left. That means that almost immediately your 4.4kw battery is going to start degrading as cells die off. The odds of this wall making 3 kw in 4 years is slim. So you will fairly quickly find yourself in perpetual maintenance mode.

What he needs to do, or what we need to do, is make that wall with:
1. Replaceable fuses (the ones that he talked about that would pop when a battery failed).
2. An LED that indicates which battery / fuse had failed.
3. Individual replaceable batteries.

That way you don't have to unsolder the whole damn thing to replace three or four and maintaining your power wall is as easy as maintaining the TV Remote in your living room. Think about it. You get five or six that died off over last month and instead of shelling out thousands of dollars, you go down to Costco and buy a pack of 10 or 20 batteries for $60 and just pop them in. Making this an end-user serviceable product will open it up to a LOT of people and reduce the overall amount of cash that it takes to keep it operational. Because remember - all of the profitability and cost offset models assume the device is working at 100% - and we all know that no solar set up and no battery set up operates at 100% indefinitely. As a matter of fact degradation starts immediately and is measurable in the first year. Then five years down the road batteries are really starting to show it. Go ten years and you have to start considering large replacement. But if you had done small replacements all along, then you kept close to the 100% mark and you won't have another $3500 payment in 10 years.


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## GTGallop

One other criticism of his design, if I may.

I felt like he didn't allow for ample air flow around the batteries and had no thermostat / cooling fan or vents in the power wall. I would make temperature a much higher design priority than he did.


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## Atilla

GTGallop said:


> There is some nuance in how he explained that. Basically you have to go back and watch two prior videos that he linked via picture in picture, but the short and simple is that he buys dead laptop batteries and usually it is only one cell that failed - the rest are still viable. He has a lot of labor and equipment tied up in testing and separating the wheat from the chaff. That never factors in to his final. But in the end he gets to $300 by what he spent and how many viable cells he ended up with.
> 
> What he doesn't outline is that these are all heavily used cells and may have less than 50% of their life left. That means that almost immediately your 4.4kw battery is going to start degrading as cells die off. The odds of this wall making 3 kw in 4 years is slim. So you will fairly quickly find yourself in perpetual maintenance mode.
> 
> What he needs to do, or what we need to do, is make that wall with:
> 1. Replaceable fuses (the ones that he talked about that would pop when a battery failed).
> 2. An LED that indicates which battery / fuse had failed.
> 3. Individual replaceable batteries.
> 
> That way you don't have to unsolder the whole damn thing to replace three or four and maintaining your power wall is as easy as maintaining the TV Remote in your living room. Think about it. You get five or six that died off over last month and instead of shelling out thousands of dollars, you go down to Costco and buy a pack of 10 or 20 batteries for $60 and just pop them in. Making this an end-user serviceable product will open it up to a LOT of people and reduce the overall amount of cash that it takes to keep it operational. Because remember - all of the profitability and cost offset models assume the device is working at 100% - and we all know that no solar set up and no battery set up operates at 100% indefinitely. As a matter of fact degradation starts immediately and is measurable in the first year. Then five years down the road batteries are really starting to show it. Go ten years and you have to start considering large replacement. But if you had done small replacements all along, then you kept close to the 100% mark and you won't have another $3500 payment in 10 years.


I think Tesla tried to sue him, He referenced one video that he had to take down and I couldn't figure out why he spent so much money on the glass panel that said telsa. My guess is that they settled and basically he could use the name Tesla because it is already out there, but something in at least one of his videos went to far.

I also think that his fuses are the leftover leads from resistors that he used on another project.

I thought that the failure rate would be high and wanted to make a battery tray of sorts so they would be easily replaceable. The LED thing is brilliant though. What I haven't figure out is if you can rig an LED that tests one cell when it is wired in series or parallel. Also, even dead, these things might light up an led so I'm not sure how to determine if the battery is indeed not taking a charge. If you wired the led so that it only lights as current is going into the battery, it seems that might work. Your LED's would only show cells not taking a charge when they were being charged. That might work very well, because you wouldn't be testing the battery, but it's acceptance of current. That way you might find LEDs that were rated at the charging capacity of the batteries and therefore not need a resistor or worry of LEDs burning up. From what I can tell these cells push to much current for a LED to last very long.

This solution presents two problems, I think. First is that you might find that the stronger (or weaker) batteries charge first and suck more juice, therefore your LEDs might not all light up at the same time. I.E 12 batteries in a bank, apply charge, the ones that take a charge well (or are more discharged, therefore not as AHish, IDK) might light up the LED strongest at first and then taper off as they top off, resulting in other LEDs turning on, getting brighter as they start to charge. So you might have to observe which LEDs shine first or which shine last to find your dead cells. I'm not an electrical engineer so I have no idea if I'm barking up the right tree, yet.

The second problem is that LED are one-way. So if you charged them through an LED, you couldn't discharge them (I.E. use them for juice) through the same circuit (LED). So if this would work you'd have to have a charge circuit going to the battery and a load circuit coming out. This doesn't seem like a big problem, just more soldering, until you start charging while you are using them. Might not matter, but I don't know.

I definitely need to study that DC Electronics book I've had since I was 19 and been meaning to read.

I'm charging my test batteries and they are so far taking a charge. By that I mean the voltage is increasing and holding, at least so far. I'm using a hobby charger I bought for charging NiCad and NiMH batteries and the instructions were simply to charge at 10% of the AH rating. Back in the day, I'd charge a 500 mAH battery at 50mA until warm. This charger is putting out 18 volts and I'm using the 500mA setting, I've only had one battery get slightly warm. Mostly I've stopped charging once they get over 4 volts and some are getting there in an hour. I left one overnight and it reached 4.3 volts, has held it all day and wasn't appreciably hotter than body temp when I checked it in the morning.

I suspect that a lot of laptop batteries go bad because of the thermal sensor. Batteries are a safety liability and I think that the manufacturers are very conservative when it comes to overheating. I also think that most thermal sensors are crap.

If anybody has any ideas about putting these thing under a load, I'd love to hear it.

As for removability, so far all I've come up with is a tray with old-school copper/brass weatherstripping lining each side. Problem is how you you manage the groups in parallel into a series. Again, I need to read/draw it out...


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## quinnbrian

Right now batteries are at an all time high(price). When I bought my batteries 5 years ago, I paid $2700.00 for 8 x 6volt batteries and now the same batteries are $3700.00. 
Great idea, does anyone have any plans/how to's, for a lead acid , home built battery. But this is something I'm going to look into a little more....Maybe a group buy on some new batteries to build with...??


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## Medic33

This a neat idea but in know way does it compare to what tesla really did he wanted everyone to have cheap power and did it to bad his notes and plans have been hidden or destroyed , if his secret got out it would spell doom to the power company.
So wil2 if your a genius as I suspect I bet you could figure it out so start cooking and research nik testa' stuff on electricity and change the world.


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## TacticalCanuck

Very cool. But beyond me. I wouldn't play with this stuff without a little formal education like a electrical class at community college via night school or the like.


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## GTGallop

Given the age of the batteries he used and the tedium involved in checking for duds and assembling sub-groups to work together, I think something like this, while more expensive, falls into the skill set of the average Joe a lot easier.
https://www.google.com/shopping/product/17812360239324148542

$500 will get you set up with 24v over 30ah if my math is right. That should be more than enough to bridge the night with comfort and still run some bigger electronics. Maybe not a tread mill but definitely lights (LED), computers, comms, a TV/DVR/Roku box and maybe a few pulses from the disposal in the sink.


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## Atilla

I am now charging a 18650 through an LED at 50mA, 500mA blew up the first LED. I'm using power and HD lights from old computer cases, about as simple an LED as you can get. I tried to charge one of the 0 volt batteries (completely dead) and the LED did not light, (I have not tried to leave a completely dead battery on the charger for any length of time yet, with or without an LEd in the circuit). My meter shows the voltage going up on a "good" cell taking a charge.. It doesn't go up as fast as when I was charging at 500mA, but that blows these little LEDs I have.

That the first LED blew at 500mA tells me that the LED could act as a fuse on the charging end of things. I'm assuming that if the battery shorted while charging the LED would blow before the battery melted given the appropriate sized LED.

I'm hoping that the LED will grow dim as the battery nears full charge. I'd be surprised if it did given the mundane nature of the LED I have, but you might be able to size one that would.


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## 8301

quinnbrian said:


> Right now batteries are at an all time high(price). When I bought my batteries 5 years ago, I paid $2700.00 for 8 x 6volt batteries and now the same batteries are $3700.00.


What amp hr batteries did you go with? I'm running Crown L-16s at 395 amp hr (20 hr rate) 48v (8 batteries) for $2560 after delivery cost. $2340 before delivery to my home/business but I have a forklift to unload.


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## Montana Rancher

quinnbrian said:


> Right now batteries are at an all time high(price). When I bought my batteries 5 years ago, I paid $2700.00 for 8 x 6volt batteries and now the same batteries are $3700.00.
> Great idea, does anyone have any plans/how to's, for a lead acid , home built battery. But this is something I'm going to look into a little more....Maybe a group buy on some new batteries to build with...??


I am currently helping a close friend put in a total solar setup (off grid) and we are getting 8L16 370 ah batteries from Parts Plus for $229 plus a $30 core charge. I have used those exact batteries in my solar system for several years with no problem. So currently 8x 6 volt batteries are $1650 including core deposit, IMO these lead acid batteries are old school but will put everything here to shame in its 10-12 year life expectancy and ease of use.

I Like the Tesla wall but it is 4x times more than using Lead batteries.


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## quinnbrian

FoolAmI said:


> What amp hr batteries did you go with? I'm running Crown L-16s at 395 amp hr (20 hr rate) 48v (8 batteries) for $2560 after delivery cost. $2340 before delivery to my home/business but I have a forklift to unload.


Mine are Interstate, same amp hours.(about 100-110 pound a piece) They were $2700.00 Canada...5 years ago, know there $1000.00 more...crazy!!


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## quinnbrian

Montana Rancher said:


> I am currently helping a close friend put in a total solar setup (off grid) and we are getting 8L16 370 ah batteries from Parts Plus for $229 plus a $30 core charge. I have used those exact batteries in my solar system for several years with no problem. So currently 8x 6 volt batteries are $1650 including core deposit, IMO these lead acid batteries are old school but will put everything here to shame in its 10-12 year life expectancy and ease of use.
> 
> I Like the Tesla wall but it is 4x times more than using Lead batteries.


I like lead acid too. Easy use and maintain. The old school , way works great. My generator is a 1967, and will out last the two other generators, that it replaced!


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## Will2

quinnbrian said:


> Right now batteries are at an all time high(price). When I bought my batteries 5 years ago, I paid $2700.00 for 8 x 6volt batteries and now the same batteries are $3700.00.
> Great idea, does anyone have any plans/how to's, for a lead acid , home built battery. But this is something I'm going to look into a little more....Maybe a group buy on some new batteries to build with...??


what batteries are these?

What type? How many AH etc...

Most batteries I have seen are a 5x or 10x less than that.


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## 8301

Will2 said:


> what batteries are these?
> 
> What type? How many AH etc...
> 
> Most batteries I have seen are a 5x or 10x less than that.


Will, Renewable Energy batteries are built much heavier with thicker plates than less expensive Auto Zone deep cycle batteries. They often have different minerals mixed in the lead, non conductive matts between to plates to resist shorting if the plates ever warp from heat, and deeper bottom sump areas to keep flaked off lead deposits from shorting the bottom of the plates. This makes them much more durable in long term deep cycling applications but makes them cost much more.

An Auto Zone type deep cycle battery will last 2-3 years under heavy cycling (40 - 50% depth of discharge most days with often incomplete recharging) vs 6-11 years for a good quality renewable energy type lead acid battery. And Walmart cheap batteries will rarely last more than 2 years under such abuse.

There is a big difference between someone who has a few solar panels and batteries and occasionally runs a toaster oven off them and someone who works those batteries every night running lights, tvs, hair dryers, and water pumps even after 2 days of rain so they don't get fully recharged.


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