cowpen
Member
- Joined
- Sep 6, 2018
- Messages
- 47
Here's my Everglades camp electrification project.
I should start by saying I very much appreciate the knowledge and expertise that you all share in this forum. I'm learning a lot. In posting my own mistakes and successes I hope that someone else can benefit as I have by reading about your projects.
So we have a cabin and 3 acres in the Big Cypress National Preserve in the Florida Everglades which we've owned since the 1960's before it was a Preserve. The location is very remote and reachable only by a loooong ride via off-road vehicle (swamp buggy). We love spending time there, but it's often hot, humid & uncomfortable so we can only really enjoy it from October to May. Even then it can be unpleasant some days. Learning about this Powerwall idea got me thinking about the possibility of trying to make the place a little more comfortable.
A little about the current setup. The camp is very basic - about 20 x 40 ft with a metal roof and no insulation. The "windows" are screened 4x8 ft openings with plywood awnings which are propped open while we're there. These get bolted down to keep the bears out while we're gone. It's always been a hunting camp even though none of us have hunted in years. So really just a relaxing, beer drinking, "get away from the rat race" camp. Sleeps 7.
About 5 years ago, I "solarized" the place with an 18W panel I salvaged from a USCG dumpster, a 20A Morningstar PWM controller, and a 91 Ah "D" size John Deere tractor battery. Certainly not the ideal setup, but everything was free and has been working great for 12V LED lights, charging tools & cell phones, and running small computer fans to "knock the sweat off". The little solar panel is probably way undersized for the battery, but we're rarely there for more than 2 nights, and often go a month or more between visits. It pretty much stays fully charged.
So I'm thinking now about how best to use these 18650's I'm collecting to make things better. We have an ancient 1940's full size Servel gas refrigerator / freezer that works great and a gas stove / oven. No indoor plumbing except a kitchen sink drain.
Some of the things I'd like to add:
14s60p = 840 cells @2100 mAh average.
14 packs * 3.7V = 51.8V
51.8V * (60 cells * 2.1 Ah) = 6.526 KwH
I'm numbering cells individually and tracking them in an Excel spreadsheet. I'm only planning to keep cells better than 1900 mAh & 75% of rated capacity. No "heaters" allowed. Here's what I've got so far in about a month of scavenging and testing. I added another pack this morning, so we're halfway there:
I cobbled together an 8 slot TP4056 charger that really helped speed up the process. Still only have two OPUS testers though so that's my bottleneck. I'm in no big hurry.
Not planning to start soldering busbars until I have enough cells for the entire string. I want to distribute capacity as evenly as possible across packs. I should probably start practicing with some throwaway cells first. I've ordered a fat iron. Is plumbing solder just as good as electronics solder for this application? Is there any value to using a solder paste pen to ease this process along? Last thing I want is to ruin cells by overheating them.
I definitely plan to include a BMS. Batrium is very nice - especially the monitoring. I'll probably go that route unless I find a less expensive solution.
I'm still really concerned about safety of the system with nobody there to monitor for problems. I'm considering putting the entire system in a separate shed and just running AC to the cabin. That way if something goes wrong and it burns up we minimize our losses. Anyone else using this approach for absentee powerwall systems? Need someone to put my mind at ease about this.
In any event, I'll be assembling and testing everything in my barn at home for months before I declare it's safe. Then I'll take it down to camp for installation.
Thanks for reading. I know it's kind of long. I'll be posting shorter updates when they happen.
I should start by saying I very much appreciate the knowledge and expertise that you all share in this forum. I'm learning a lot. In posting my own mistakes and successes I hope that someone else can benefit as I have by reading about your projects.
So we have a cabin and 3 acres in the Big Cypress National Preserve in the Florida Everglades which we've owned since the 1960's before it was a Preserve. The location is very remote and reachable only by a loooong ride via off-road vehicle (swamp buggy). We love spending time there, but it's often hot, humid & uncomfortable so we can only really enjoy it from October to May. Even then it can be unpleasant some days. Learning about this Powerwall idea got me thinking about the possibility of trying to make the place a little more comfortable.
A little about the current setup. The camp is very basic - about 20 x 40 ft with a metal roof and no insulation. The "windows" are screened 4x8 ft openings with plywood awnings which are propped open while we're there. These get bolted down to keep the bears out while we're gone. It's always been a hunting camp even though none of us have hunted in years. So really just a relaxing, beer drinking, "get away from the rat race" camp. Sleeps 7.
About 5 years ago, I "solarized" the place with an 18W panel I salvaged from a USCG dumpster, a 20A Morningstar PWM controller, and a 91 Ah "D" size John Deere tractor battery. Certainly not the ideal setup, but everything was free and has been working great for 12V LED lights, charging tools & cell phones, and running small computer fans to "knock the sweat off". The little solar panel is probably way undersized for the battery, but we're rarely there for more than 2 nights, and often go a month or more between visits. It pretty much stays fully charged.
So I'm thinking now about how best to use these 18650's I'm collecting to make things better. We have an ancient 1940's full size Servel gas refrigerator / freezer that works great and a gas stove / oven. No indoor plumbing except a kitchen sink drain.
Some of the things I'd like to add:
- 110V Ceiling fans - probably 2 or 3.
- An efficient LED TV & satellite dish (so we don't miss the football games).
- Convert existing 12V LED lighting to AC.
- Power tool charging, and occasional corded tools.
- Maybe an LTE modem / router if I can figure out how to pull in a nearly non-existent signal. If I get that figured out, I'd love to add remote powerwall monitoring, weather station, WiFi game cameras, etc.
14s60p = 840 cells @2100 mAh average.
14 packs * 3.7V = 51.8V
51.8V * (60 cells * 2.1 Ah) = 6.526 KwH
I'm numbering cells individually and tracking them in an Excel spreadsheet. I'm only planning to keep cells better than 1900 mAh & 75% of rated capacity. No "heaters" allowed. Here's what I've got so far in about a month of scavenging and testing. I added another pack this morning, so we're halfway there:
I cobbled together an 8 slot TP4056 charger that really helped speed up the process. Still only have two OPUS testers though so that's my bottleneck. I'm in no big hurry.
Not planning to start soldering busbars until I have enough cells for the entire string. I want to distribute capacity as evenly as possible across packs. I should probably start practicing with some throwaway cells first. I've ordered a fat iron. Is plumbing solder just as good as electronics solder for this application? Is there any value to using a solder paste pen to ease this process along? Last thing I want is to ruin cells by overheating them.
I definitely plan to include a BMS. Batrium is very nice - especially the monitoring. I'll probably go that route unless I find a less expensive solution.
I'm still really concerned about safety of the system with nobody there to monitor for problems. I'm considering putting the entire system in a separate shed and just running AC to the cabin. That way if something goes wrong and it burns up we minimize our losses. Anyone else using this approach for absentee powerwall systems? Need someone to put my mind at ease about this.
In any event, I'll be assembling and testing everything in my barn at home for months before I declare it's safe. Then I'll take it down to camp for installation.
Thanks for reading. I know it's kind of long. I'll be posting shorter updates when they happen.