Tesla Powerwall

Post anything about batteries here. Lead acid, rechargeable, whatever.
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john3voltas
Posts: 7
Joined: Mon Feb 09, 2015 2:50 am

Tesla Powerwall

Post by john3voltas » Sun Jan 10, 2016 5:06 pm

Greetings.
Even though I've registered for some time already I still haven't ventured on a solar+battery project.
I have several reasons why I still haven't tried it:
1-I live on a flat of a tall building and aside from 1 balcony I don't have a place for the solar panels.
2-My knowledge on electricity is basically 0.
3-My DIY skills are also close to 0.

But the main reason is I have a toddler in the house and I am afraid I would put her in danger with the batteries and cabling insulation.
You all must know Tesla very well. To me it seems a bit like the Apple of the electricity. They usually pick others' ideas, wrap them inside a nice plastic shell and sell it for 3 or 4 times the initial price. Sounds a bit like Apple doesn't it?
Anyway this time around they have launched a "new" product that is supposed to revolutionize every home: the powerwall.
Apparently it's a set of Lithium batteries that achieve 7kWh. Here's a link to their site https://www.teslamotors.com/powerwall
Anyone knows this product? How would it rate versus a lead acid battery set?
At least it's gotta be a safe product right? They give 10 years warranty and say we can mount it indoors.
I guess 7kWh would do for me since my bill averages 4.5kWh per day...

Code: Select all

    Technology
    Wall mounted, rechargeable lithium ion battery with liquid thermal control.
    Model
    7 kWh $3,000 For daily cycle applications
    Warranty
    Ten years
    Efficiency
    92% round-trip DC efficiency
    Power
    3.3 kW
    Voltage
    350 – 450 volts
    Current
    9.5 amperes

techman
Site Admin
Posts: 1322
Joined: Thu Dec 22, 2011 11:49 am

Re: Tesla Powerwall

Post by techman » Thu Jan 14, 2016 12:17 pm

First the voltage is way off the usual standard voltages, meaning you have to buy all the equipment from them.

Standard home solar panels are 24 volts. You can run them in series for higher voltages.

Standard home wiring is 120 volts. Standard storage batteries are 12 volts, 24 volts or 48 volts using banks of 12 volt batteries.

Standard power inverters are rated at either 12 volts to 120 volts (US) or 24 volts to 120 volts (US). Rare but sometimes used are 48 to 120 volt inverters.

I would stick with standard equipment for way lower cost over the lifetime of the equipment.

john3voltas
Posts: 7
Joined: Mon Feb 09, 2015 2:50 am

Re: Tesla Powerwall

Post by john3voltas » Sat Jan 16, 2016 10:07 am

Thanks for the reply, Troy.
You're living our dream, because we'd love to go off grid.
But it's gotta be rough on you too. Winters must be real tough and you have to chop trees for fireplace wood and the wind destroys your windmill towers. And in the end you still find time to deliver inspiring videos and encouraging replies here in the forum. :)
Wish I could sell this apartment and buy a cheap small house with a backyard so that I could live more from what nature gives us. But right now I can't find a buyer that wants to pay at least 70% of what I payed...
Besides, the Lehman Brothers bank crisis simply exploded the bank interest on house loans here in Portugal. Meaning that even if I could somehow deal with the 30% deficit I would end up paying a lot more on a new loan for a 60 or 70yo house. Since I'm basically broke, this is completely out of the question. :(
And yet I still feel compelled to buy a cheap old battery, maybe revive it with a bedini motor/energizer and then slowly buy photovoltaic breads and build a DYI solar panel. Just to check on what I can get with it. Maybe that way I can better understand what I actually can achieve with my balcony full of solar panels...
Do you have a nice tutorial on these? On how to revive an old battery with a bedini and how to make your own solar panel?
Thanks mate.

PS: forgot to ask you: can we achieve the same specs (7kWh - 9.5amps) with standard batteries on a 51.2” x 33.9” x 7.1” ?

techman
Site Admin
Posts: 1322
Joined: Thu Dec 22, 2011 11:49 am

Re: Tesla Powerwall

Post by techman » Thu Jan 28, 2016 9:36 am

Thank you. Yes just experiment with what you have and learn until you manage to find a nice home.

I have a website on the Bedini motor here:
http://www.thedoityourselfworld.com/ssg ... storer.php

And I wrote a book on how to make your own solar panels:
http://www.lulu.com/spotlight/TheDIYWorld

I am not sure what you are asking about the batteries. The more batteries you have, the more stored energy you have. But then you need enough solar panels to charge those batteries up to full in a single day of sunlight.

The general rule is to have enough battery storage to last you three days of clouds. I have never attained that yet though. I am up to a day and a half. But one day I will get these solar panels off the ground and have more power.

john3voltas
Posts: 7
Joined: Mon Feb 09, 2015 2:50 am

Re: Tesla Powerwall

Post by john3voltas » Thu Feb 04, 2016 2:36 am

techman wrote:Thank you. Yes just experiment with what you have and learn until you manage to find a nice home.

I have a website on the Bedini motor here:
http://www.thedoityourselfworld.com/ssg ... storer.php

And I wrote a book on how to make your own solar panels:
http://www.lulu.com/spotlight/TheDIYWorld
Thanks for the links. :)
techman wrote:I am not sure what you are asking about the batteries.
I see. Well, Tesla says their batteries can do 7kWh with 9.5amps on a frame with these dimensions 51.2” x 33.9” x 7.1”.
I've got to admit that the specs are interesting and that the dimensions are great because I can see a couple of walls that I could use with those dimensions.
Do you think we could make something similar with lead-acid batteries? Something that would do 7kWh with 9.5amps with those dimensions of the Tesla Powerwall?

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