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The Outhouse Powerwall
Thought I'd post my build even though it won't really be ready until this summer. But I figured I'd start posting my progress! Can't remember how I got started, but it was around mid-Oct and looking at Tesla powerwalls, and probably stumbled on hbpowerwall's youtube. My plan is to build an outhouse in the back and house all the batteries in it. My solar panels will be a ground mount but is basically laying on the lawn at the moment. By the summer I'll have the outhouse built and the solar panels mounted.

So far I've managed to build my first 7s60p pack. Here's what I'm using:
  • PIP2424LV from MPPSolar ($550)
  • 9x 245W used solar panels ($50/ea)
  • 420 cells, roughly 3kwh of LG batteries mostly from alarmhookup to speed up the process (roughly $550)
  • Celllog 8M for BMS ($20)
  • 1S balancers (2x) to manually balance as needed. ($40)
My cells are arranged at 60p just because of the batteries I had at hand, but it seems the right way. I followed owitte's build in a way that I like to be able to increase the pack size as necessary by just adding more cells. But then I wanted a denser configuration, so instead I choose a rack style. I also brought both ends of the terminals up front, bringing one of the bus bars on the rear to the front. This allows me to front load the packs and not worry about anything in the back. Right now there's only one layer, but I am imagining at least two or three layers, with a copper bus bar running down each pack, so basically turning a 60p configuration into a 120p or 180p if need be.

Each layer of 7s60p is roughly 3kwh so I am planning to get to at least 12kwh by summer. My progress with the PIP2424LV so far is pretty abysmal. Partly to blame is the poor mounting of the solar panels, or lack thereof. Then there's the winter hours where I spend at least 18 hours on batteries. Combine that with that the PIP takes roughly 1200w to run, giving me roughly 2kwh of power out of my pack. So out of the 3kwh pack, I can barely run 100w continuously. I started with 6x panels, and I just threw another 3x panels this weekend, and it helped extend the running time during early and late day. Extending to 6kwh I expect to have most of these issues to go away as it allows me to be able to buffer at least one day of crappy weather.

I'm using a Celllog 8M as the BMS, and I'm planning on hooking it up to the ABB shunt trip breaker maybe next weekend. I calibrated it to match my multimeter and it seems to do a good job. I'm also using 2 1S balancers like owittes but I only hook up when I need to. Early on Pack 3 had an issue and it kept going out of sync, so the balancer seemed to balance it out pretty well. It balances at around 300ma at 100mv difference and increases with more differential. Then later I found the issue, I forgot to solder two fuses to the bar, so the pack was short 4 cells. After that it was fine.

Chiptosser, Korishan, Oderus420 And 7 others like this post
Nice setup...
But how are the packs mounted?? it looks like they are hovering... Wink
Wattsup likes this post
18x 300Wp solar off grid and 10x 180Wp solar tracker grid-tie
10KW 3phase hybrid inverter. 40Kwh 18650 storage (for now)
My setup:
that toolbox above the packs, looks a bit scary, if you take out one of the tools and the other one falls down,.... could get nasty

I like the setup, looks neat.
thanar and hbpowerwall like this post
@wim: they are a short particle board shelf. I almost missed it, myself. You can see it barely on the left side under the mouse (black dome looking thing)

I agree with Stefaan and HBPowerwall (and anyone else who likes Stefaan's post); something falling in between the packs could get ugly. But, this is just a test rig and they won't be staying there. Perhaps the protective cover (maybe a piece of cardboard even) was taken off for the sake of the pictures Smile

Nice clean look overall. I'd like to see how you build your outhouse (at first, I was wondering why you were putting a powerwall in an outside bathroom Tongue but that's what's you're calling the building the packs and hardware will go into)
Proceed with caution. Knowledge is Power! Literally! Cool 
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Thanks all! Hehe it does look like it's floating! Yes there is a shelf there! I had to get it off the workspace since I couldn't do anything else if I kept it on the table. And yes there isn't anything on those containers other than pens and non conductive stuff! I removed those containers on the right already Smile Anything falling down the middle will be unfortunate but not too critical, just 4x5 holders and pens. I use 2x1 spacers up front to protect the lugs from having anything cross connect or short accidentally by either bumping or touching anything conductive. Saw hbpowerwall's youtube on when he dropped something on them causing the short Wink On the right of the batteries is the PIP and a whole bunch of bussman fuses/disconnects/breakers but too ugly to look at since it's just a test bed.

Yes that's the plan for the summer to build the 'outhouse' Smile
Nice looking build so far  Wink
                                                Choose LiFe  Wink

                      May all your batteries be fully charged and perfectly balanced  Cool
(12-26-2017, 01:43 PM)Korishan Wrote: @wim: they are a short particle board shelf. I almost missed it, myself. You can see it barely on the left side under the mouse (black dome looking thing)

are you sure ??  Looks like a kind of anti gravity device to me... Big Grin
18x 300Wp solar off grid and 10x 180Wp solar tracker grid-tie
10KW 3phase hybrid inverter. 40Kwh 18650 storage (for now)
My setup:
Finally had some luck with batteries this weekend! Hopefully enough to build the next 3kwh! Angel

Got a whole bunch of Lenovos. A majority of them are stuffed with Sanyo cells. I know they've been reported to be heaters, but has anyone been successful in using them in any large capacity?

These are reported to be UR18650FM and in the cell database to be 2600mah. I'm getting about 2400-2600mah on them.

Hans Tuchel, owitte, Korishan And 2 others like this post
Completed my first month on solar! Did a data dump from the Watchpower software into excel. Generated a total of 89kw!! Got to thank this forum for all the ideas that I've been able to get!

Power output wasn't great but I didn't run it on full power because it isn't rigged up properly yet. I didn't have my kill-a-watt meters running on the right dates so I can't measure the utility usage so my rough figures would be about 30kw would have been used by the PIP and another 5kw to other losses. So I can only estimate that would make me generate around roughly 50kw of power! At around .18 per kw that would be a whopping $9 saved! Still awesome!

This was a really fun month! I got to say to everyone else starting out that it's definitely a waiting game to source all your materials. I don't think I was as aggressive in hunting for batteries as Pete but I must have asked everyone I know about it. In the end I was finally able to score another find last weekend to last me a while! Solar panels were the same, I scoured craigslist every day until I found them. In a way I'm glad that it was a 24v system since the packs are only 7s and I was able to build it quickly by cheating a little and bought it from alarmhookup when he had those lg batts. If it was 48v I wouldn't have jumped the gun, but I'm glad I did otherwise I would not have a functioning system today and only started to build my packs. I'm too impatient for that.

I did find that properly sizing your battery to solar panels to be quite crucial. I have way too many panels that I'm already fully charged before noon even though the packs are fully drained. I can't wait for the next packs to be done.

Going to be the last update for a while cause going to be traveling soon so this project will be on hold for at least a month.

Sitting above my current packs are the next 3kw packs all salvaged and waiting to be tested!  Big Grin
owitte and Korishan like this post
Been a while since I updated! Over the winter I had been busy sketching up my designs and waiting until the weather was cooperating. Unfortunately it rained every possible weekend and I didn't have any chance for progress until this month when I blew up my PIP. My design was to build something that was standalone and somewhat away from the house. I tried building it with the least amount of waste possible.

I started on the foundation about two months ago using cinder blocks. This took me a while because first I thought about pouring concrete (even bought some bags of concrete mix) but ended up going the cinder block route. Ended up much easier and less messy.

Once that was done the rest just fell into place (I love drawing it up in CAD, it took most of the guesswork out!). Being a little guy, it did take me a while to frame it all up! Big Grin

I tarped the entire frame as a moisture barrier and insulated the space with insulation. The weather during winters here drop below freezing often so this outhouse is going to keep warm and stay that way!

The siding was made using imported european lumber and fine plywood (aka. shipping crates). Other than that the only thing I really bought from Home Depot were the 2x3s, 4x4 for the base and a bag of insulation material. 

rodagaster and Korishan like this post

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