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DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

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Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#11

Post by gamad »

stephengillie wrote: post #10
ficklepickle wrote: post #3

This sounds like it could be rather dangerous, no? Connecting up a bunch of old lithium cells of unknown origin and using them hard. I'd also worry about an insurance claim being denied if it burned my house down. However, I very much approve of the DIY ingenuity and repurposing of old stuff.

The hyperbolic response isn't warranted, as these are nearly identical lithium cells of known origin. Were they all different random cells, or if disassembly were required, then one might catch fire or explode like a small firecracker. This isn't much more dangerous than putting batteries in a toy car, or putting gasoline into a hybrid.

I'm a EE, and a licensed PE. I wouldn't do this.

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#12

Post by hwillis »

extr wrote: post #6
ficklepickle wrote: post #3

This sounds like it could be rather dangerous, no? Connecting up a bunch of old lithium cells of unknown origin and using them hard. I'd also worry about an insurance claim being denied if it burned my house down. However, I very much approve of the DIY ingenuity and repurposing of old stuff.

Yes, this is extremely dangerous. I'm sure some of the people mentioned have the expertise to pull it off, but for most this is like building a massive bomb in your garage. There's a reason that 18650s aren't generally sold directly to consumers, in most applications they need dedicated circuitry to be used safely. And that's for brand new cells, it's another story entirely to be using random collections of "old" cel…

Theres no way to detonate a pack like this. 18650s have a pressure release, so the cstch fire but dont explode. In the very unlikely event that fails, a cell could burst, but it cant cause other cells to burst unless the entire pack failed to vent under extreme pressure.

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#13

Post by extr »

cyphar wrote: post #2

One of the really disappointing things about Tesla is how incredibly proprietary all of their products are. For a company that has such lofty goals as "saving the world", it feels wrong to me for them to then sell DRM cars and unrepairable black boxes. Maybe I'm just too idealistic, but surely if we have an opportunity to create a new market for solar devices why would we decide to recreate the proprietary world of t…

This isn't unique to Telsa, all vehicles are becoming more difficult to repair as computers and software replace what used to be handled by mechanical systems. I would actually much prefer to drive next to a Tesla knowing that the guy behind the wheel (potentially staring into space as it drives itself) hasn't implemented any "hacks".

A similar argument exists for why DIY battery banks are not ideal. It's not inconceivable that some dedicated hobbyist engineer pulls it off in a safe way. But how would you feel if you were over in your neighbors garage and noticed he had haphazardly wired 600 18650 cells together based on a design he found on the internet?

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#14

Post by stephengillie »

gamad wrote: post #11
stephengillie wrote: post #10

Earlier quoted context omitted.

The hyperbolic response isn't warranted, as these are nearly identical lithium cells of known origin. Were they all different random cells, or if disassembly were required, then one might catch fire or explode like a small firecracker. This isn't much more dangerous than putting batteries in a toy car, or putting gasoline into a hybrid.

I'm a EE, and a licensed PE. I wouldn't do this.

Please excuse my ignorance - what is a licensed PE?

Edit: Thanks for the answers. 2 questions:

1. Why would you not do this?

2. Were you to do this, what precautions would you take?

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#15

Post by hwillis »

cyphar wrote: post #2

One of the really disappointing things about Tesla is how incredibly proprietary all of their products are. For a company that has such lofty goals as "saving the world", it feels wrong to me for them to then sell DRM cars and unrepairable black boxes. Maybe I'm just too idealistic, but surely if we have an opportunity to create a new market for solar devices why would we decide to recreate the proprietary world of t…

Tesla supported Kevin Mahaffey and Marc Rogers when they were hacking at their friends model S and trying to get root access. The model 3 repair support guide just came out and has diagrams of the battery pack down to the cells. Yes, they dont put the design of the car on github. They are hardly "incredibly proprietary" though.

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#16

Post by gtCameron »

stephengillie wrote: post #14
gamad wrote: post #11

Earlier quoted context omitted.

I'm a EE, and a licensed PE. I wouldn't do this.

Please excuse my ignorance - what is a licensed PE? Edit: Thanks for the answers. 2 questions: 1. Why would you not do this? 2. Were you to do this, what precautions would you take?

Professional Engineer

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#17

Post by hwillis »

stephengillie wrote: post #14
gamad wrote: post #11

Earlier quoted context omitted.

I'm a EE, and a licensed PE. I wouldn't do this.

Please excuse my ignorance - what is a licensed PE? Edit: Thanks for the answers. 2 questions: 1. Why would you not do this? 2. Were you to do this, what precautions would you take?

Professional engineer

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#18

Post by planteen »

stephengillie wrote: post #14
gamad wrote: post #11

Earlier quoted context omitted.

I'm a EE, and a licensed PE. I wouldn't do this.

Please excuse my ignorance - what is a licensed PE? Edit: Thanks for the answers. 2 questions: 1. Why would you not do this? 2. Were you to do this, what precautions would you take?

Professional Engineer. There's an Engineer in Training certification first, typically gained by passing a Fundamentals of Engineering exam in college. Then you work for a few years under a PE and take an exam to become a PE yourself.

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#19

Post by gamad »

stephengillie wrote: post #14
gamad wrote: post #11

Earlier quoted context omitted.

I'm a EE, and a licensed PE. I wouldn't do this.

Please excuse my ignorance - what is a licensed PE? Edit: Thanks for the answers. 2 questions: 1. Why would you not do this? 2. Were you to do this, what precautions would you take?

Someone licensed by their (US) state as an Engineer, and the only person (in most states) who can legally call himself an Engineer.

https://www.nspe.org/resources/licensure

Re: DIY Powerwall Builders Are Using Recycled Laptop Batteries to Power Their Homes

#20

Post by ghaff »

stephengillie wrote: post #14
gamad wrote: post #11

Earlier quoted context omitted.

I'm a EE, and a licensed PE. I wouldn't do this.

Please excuse my ignorance - what is a licensed PE? Edit: Thanks for the answers. 2 questions: 1. Why would you not do this? 2. Were you to do this, what precautions would you take?

I'm not sure how relevant it is as an appeal to authority measure, but in the US there is a Professional Engineer license. It's mostly relevant when you have to sign off on designs for regulatory bodies.
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