Elmo
Member
- Joined
- Feb 19, 2017
- Messages
- 189
Hi y'all from the Oconee National Forest in Georgia, USA. We are about as rural here as you can get in the Eastern US.
I'm of advanced age and decrepitude, retired from a career of being the one they call in when on the spot shade tree engineering is needed to persuade a balky piece of expensively orphaned equipment to work for another few days or weeks.
Starting four years ago I've built several ebike battery packs from salvaged 18650 laptop cells, the last few being 12s 20p and 14s 16p using Jehu Garcia's fuse wire technique with 32 gauge wire which has worked well for me at about a 6A fusing current. I'm using a (clapped out) iMax genuine B8 charger with a custom made cradle to charge 8p 18650 at once. I have a custom made serial discharge unit using a Cellog 8s, a relay and a volt/amp/watt meter to record the discharge values of the cells. I find that various combinations of 12V auto lamps work well as loads for discharging batteries, they are not exactly constant current sinks or sources but they are a lot closer to that than resistors are. By using two switchable levels of current while graphing on the PC with the Cellog 8s I can find the DC resistance of the cells in moments as well.
Now I'm working on refurbishing a large upper end but older travel trailer into a comfortable and ecologically sound off-grid home for my dog and myself. A powerwall to float me overnight and through cloudy days with only minimal use of my backup generator is what I want to get done over about the next six months or so. Climate here is such that air conditioning is nearly a necessity for sleeping three months or so out of the year so I'll need a substantial pack to carry me through the (thankfully shorter) summer nights.
I'm in the middle of setting up in a new location at the moment so I'm a bit busy to post anything really substantive but I'm definitely reading in what spare time I have.
Now, hold my beer and watch this...
I'm of advanced age and decrepitude, retired from a career of being the one they call in when on the spot shade tree engineering is needed to persuade a balky piece of expensively orphaned equipment to work for another few days or weeks.
Starting four years ago I've built several ebike battery packs from salvaged 18650 laptop cells, the last few being 12s 20p and 14s 16p using Jehu Garcia's fuse wire technique with 32 gauge wire which has worked well for me at about a 6A fusing current. I'm using a (clapped out) iMax genuine B8 charger with a custom made cradle to charge 8p 18650 at once. I have a custom made serial discharge unit using a Cellog 8s, a relay and a volt/amp/watt meter to record the discharge values of the cells. I find that various combinations of 12V auto lamps work well as loads for discharging batteries, they are not exactly constant current sinks or sources but they are a lot closer to that than resistors are. By using two switchable levels of current while graphing on the PC with the Cellog 8s I can find the DC resistance of the cells in moments as well.
Now I'm working on refurbishing a large upper end but older travel trailer into a comfortable and ecologically sound off-grid home for my dog and myself. A powerwall to float me overnight and through cloudy days with only minimal use of my backup generator is what I want to get done over about the next six months or so. Climate here is such that air conditioning is nearly a necessity for sleeping three months or so out of the year so I'll need a substantial pack to carry me through the (thankfully shorter) summer nights.
I'm in the middle of setting up in a new location at the moment so I'm a bit busy to post anything really substantive but I'm definitely reading in what spare time I have.
Now, hold my beer and watch this...