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The Powershed
I'm very excited to share my project and document my progress. Anyway, I got involved with 18650's when I spec'd them for use in my Startup's line of IoT devices. I bought a few genuine ones, then when I need to source a large quantity, I reached out to a local computer recycler. We've reached an agreement and I get about 100 ish packs per week now for free. Most of those cells go towards our IoT efforts, but I took some and put them towards building a powerwall. I can only use cells 2500+mAh for my requirements for the IoT devices, meaning I have like 1500 passing cells that don't meet the threshold. 

I've tested something like 2000 cells now. With my 7 opus chargers, I can test 80 ish per day. They are being mounted on plywood and getting neatly cabled this weekend. 5/7 of them have the fan mod with an 80mm case fan. The bigger fan works great. I don't need to do any external cooling on them. 

One week's haul

Old opus setup

I've been putting together my packs with 2000-2300 mAh cells. The system is designed to be 7s 80p with a 40 amp draw. It became hbpowerwall style by accident. I wanted to limit my draw per cell to 0.5 A (hence the 80p) for longevity and the fact that these cells are repurposed laptop cells. My capacity should be around 4.5kWh. 

The cells are being made "Tesla style", cell level fusing on both sides with 1/8w resistor legs serving as the fuse. The bus bar is 6ga stranded bare copper wire with mechanical lugs screwed on for the series connection. 

I've soldered 6 of the packs completely now. I'll add pics later when I finish the seventh (The shop is a mess). 

These packs are going into my shed - 

I've got two 100w panels on it at the moment, but it will need more. Those panels are tied into an Epever Tracer 4215BN MPPT charge controller. There's a failing offgrid system in there that will be ripped out when the lithium batteries are ready. The lithium packs will be connected to an 800w Reliable Electric pure sine wave 24v inverter. That will be connected to a little subpanel converted to a main lug one to feed the shed. 

The loads in the shed are minimal. My idle load is 20-30w. The inverter powers the lights inside and outside of the shed, the ip surveillance cameras outside and the powerwall computer. There are outlets for intermittent small power tools and chargers inside. No - the camper trailer will not be plugged into this powerwall, at least not at the moment. It would be nice to get to that point one day though. 

The powerwall computer is connected to the charge controller. The epever has neat software that lets you monitor everything about the controller and set parameters. One day when I can afford a propper batrium setup, it will be connected to the computer.
bogptrsn, camthecam, wim And 2 others like this post

Messages In This Thread
The Powershed - by howardrya - 11-22-2018, 09:04 PM
RE: The Powershed - by howardrya - 11-24-2018, 05:28 AM
RE: The Powershed - by jdeadman - 11-24-2018, 01:53 PM
RE: The Powershed - by Cherry67 - 12-07-2018, 07:48 PM
RE: The Powershed - by howardrya - 12-07-2018, 08:07 PM
RE: The Powershed - by Korishan - 12-07-2018, 08:32 PM
RE: The Powershed - by howardrya - 12-07-2018, 08:34 PM
RE: The Powershed - by howardrya - 12-15-2018, 02:21 PM
RE: The Powershed - by Wolf - 12-15-2018, 04:52 PM
RE: The Powershed - by Cherry67 - 12-15-2018, 05:53 PM
RE: The Powershed - by daromer - 12-15-2018, 04:46 PM

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