Post by captaininfosec on Nov 11, 2017 12:56:36 GMT -5
Well, a few months have gone by as I have slowly acquired more batteries, and I'm finally at the point where I can build out my first pack (~100 usable cells).
It is quite a pile of cells:
In total, I have 143 cells, with 105 in the range I want to use, 6 higher than the range, and 32 lower. I'll probably use some of the 32 lower capacity cells to build out a smaller test pack capable of 12 volts. That will let me figure out things like soldering and bus bars basics.
My plan had been to build with a 400 mAh variance, but I've ended up with cells from that range from 2000 to just under 2700 mAh. That's close enough for a first pack build. Here's how the cell repacker calculated the cell distribution for my 7S14P build:
This puts me closer to needing to sort out an inverter and some sort of small-scale solar array to play with!
Post by captaininfosec on Sept 5, 2017 7:51:48 GMT -5
My 2.0 style apron - longer for metalworking, with D-rings for leg straps to keep it from catching on things (I'm waiting on snaps and a snap tool to show up to finish those, I want them to come off easily if they get caught on something).
This version is dyed using Fieblings brown leather dye, and uses a Y harness for support. The lower part of the Y is a wet-formed belt slider, and has a height adjustment buckle in the middle of my lower back. The waist belt is also size adjustable, and like my first version, continues around part way to the front of the apron to make opening and closing the trigger snap easier.
This will get a chest pocket too, but I'm waiting on some tooling gear so I can try my hand at tooling the pocket before it gets riveted,glued, and stitched on.
I chatted with the people doing the sale and they claimed to have tested them all. I walked away with a 1 HP Baldor 110/220 unit with the motor mount for $17.50 - at that price, I can set it on the shelf for a future project.
I saw some nice older units, including Dayton and Century, and a brand new Magnetek (?) in the box. There was also a 14" South Bend Lathe company floor standing drill press for $75 which I think you could get them to go cheaper if you made an offer. It looked to be in decent condition for its age if you want a floor standing drill press.
Most of the rest of the tools were picked over, but a few interesting bits and pieces were still there - 4" jointers, a couple of old Craftsman tablesaws, an electric hacksaw, and lots of hand tools of various homeowner grade quality.
Post by captaininfosec on Aug 30, 2017 7:08:37 GMT -5
I ended up buying the 3 pack, and noted in my comments that I wished the black was on sale. Lo and behold, three black T-boxxes showed up. I'm very pleased with them, and have started to sort out leatherworking hardware into the first one.
Post by captaininfosec on Aug 25, 2017 9:05:08 GMT -5
So far, mostly Amazon. Some of the inexpensive combo packs have enough tools to be worth it even with the extras I'm unlikely to use. At my level of skill, the "nice" stuff hasn't been necessary yet.
Post by captaininfosec on Aug 25, 2017 7:07:26 GMT -5
Last night a lot of folks asked about the leather I used for my apron. Here's the link to Acadia. The leather I bought is Crazyhorse, and it has a 3 for 2 deal going on.
I currently have a 10% off coupon good for my next purchase. If there's enough interest, I could put together a group order to share the savings.
(And maybe Phil will post his stylish picture with the apron on for reference...)
Post by captaininfosec on May 27, 2017 20:57:22 GMT -5
I finally have a potential non-welding solution that would also make the packs easier to repair if a single cell failed. An Indian company called Vruzend (http://vruzend.com/) has introduced a modular cell holder design that includes bus bars and a rather nice tension based connection system for the cells. I'm debating buying a couple of sets to play with to see how they work out.
Post by captaininfosec on May 24, 2017 21:42:09 GMT -5
The Sortimo boxes are very high quality - at the same price as the Stanley and other boxes I'd buy the Milwaukee models, but I'm interested in the Sortimo as a long term storage investment.
I will end up building my own holder system for them though unless I run across a used one at a crazy low cost point!
Post by captaininfosec on May 24, 2017 9:27:54 GMT -5
Sortimo.us has a 10% off coupon this month for orders over $500 - I can't talk myself into $500 of T-boxxes, but I've drooled over them long enough that I can talk myself into a few of them.
Are others interested in buying Sortimo stuff if I am placing an order?
I'd expect to buy a handful of T-boxxes, and some additional small inserts, but might also be up for splitting some additional insert kits if others have specific kits they want.
Last Edit: May 24, 2017 10:16:00 GMT -5 by captaininfosec
Post by captaininfosec on May 16, 2017 13:14:56 GMT -5
Jim - they're active when welded. You can destroy a battery by mis-welding it, which is why I've got a dozen or so of my lower capacity rejects around to test with when I get to the point where building a pack is possible.
The gotcha is that my lowest capacity battery really sets the tone for the whole pack, which means the higher the lowest capacity is, the better my pack will be. It also means that using the nice Panasonics (the grey cells at the left end) would waste a big chunk of their capacity - they're 800 mAH or more above the 2000's that are my current (hopeful) low end.
The $200ish Ebay spot welders get decent reviews, but the more gear I buy the more likely it is that I should just buy a legit powerwall...or just build around a Tesla or Leaf pack from a parts car.
Post by captaininfosec on May 7, 2017 12:05:58 GMT -5
I'm continuing to make slow progress on acquiring cells. They fall across a pretty broad range. I've retained cells as low as 1600 mAH, but really want to be 2000-2400 for my actual build.
Right now, that means I have 58 cells between 2000 and 2499 mAH. If I include my 1900's, I have 71, and if I include the handful of 2500's, I have 75. Ideally, the first module will hold 100 cells, so I'm still a few viable packs away.
Once I get there, I need to sort out how I want to spot weld to the cells, which will be an entirely different challenge!
Post by captaininfosec on Nov 27, 2016 16:03:26 GMT -5
I'm continuing to make slow but steady progress on this project.
Below you can see the current state of my 18650 collection. I had hoped to use cells over 2000 mAh, but have found that they're relatively scarce in the recycled packs I'm able to acquire. So far, I have 14 cells over 2000 mAh out of about 75 processed so far. If I drop my threshold down to 1600 mAh, I can include 14 more cells - ideally I'll use the lower capacity cells for a test pack, then will acquire more high capacity cells for the real deal.
That also means that I have approximately 30 cells between 1200 and 1600 mAh set aside in case anybody needs some 18650's for a project. I have rejected 20+ cells that were under 1200 mAh, and they'll go back into the recyling.
I also worked on a way to charge cells faster to let me use my tester more efficiently. Below you'll see a sample of a TP4056 charger. The boards take a mini-USB cable and are easily soldered to 18650 holders to let me use a standard USB charger.
The 18650 holders are a bit finicky - they hold cells quite firmly, and the spring isn't quite strong enough to always make sure the positive terminal makes a connection. For the price, that's an easy enough fix. Total cost for the charging setup was ~$12, with a few minutes of soldering to get things all set up.
Next, I need to check around the area to see if I can find someone who recycles laptop battery packs who might part with them for free, or cheap so I can continue to process packs to build my stash of usable batteries. Right now my sources result in 2-3 packs every couple of weeks, which means this could be a really slow project with my current usable cell ratio!
Post by captaininfosec on Nov 9, 2016 21:40:47 GMT -5
Per gram prices for iron meteorites add up fast - you might try the (1990's era design) www.meteoritemarket.com/Iron.htm, or Aerolite.org for other major sources. I think the writeups on Aerolite provide more useful detail if you care about the meteorite's origin and composition.
I suspect that the folks down at the Joshua Tree Imports down in Lakeville might also have some, or may have a line on some. It might be worth giving them a call (or stopping in, if you've never been!)
Post by captaininfosec on Oct 21, 2016 20:53:00 GMT -5
I'm continuing to acquire laptop battery packs before they get recycled, but my success rate on batteries suitable for this project is pretty low. The two most recent packs (a 6 cell and a 9 cell) had a total of 2 batteries that were usable. Unfortunately, the entire 9 cell battery pack tested out at under 1200 mAh across the board, and all but two of the six cells in the smaller pack tested below my 2000 mAh lowest threshold of interest.
Here's a shot of all of the batteries I have so far that test out over 1200 mAh. As you can see, there's a lot of clustering on the right hand side of this tray. The first row of 3 purple cells is 1900 mAh and everything to the right is lower (Each cell gets information about it written on the side). Those aren't interesting to me, so I'm checking to see if a friend has a suitable project for them.
I'm now working on getting in touch with some other DIY powerwall folks within a 2-4 hour drive who have access to hundreds of laptop batteries to see if I can purchase them in bulk by weight for a reasonable sum. If that works out, I'll probably need to scale up with more chargers to test things in a reasonable timeframe!
Last Edit: Oct 22, 2016 10:54:16 GMT -5 by captaininfosec
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