italianuser
Moderator
- Joined
- Feb 25, 2020
- Messages
- 774
Final thoughts before starting:
- This heat is disrupting my chargers LOL today it's 36°C (96.8°F) outside and 28°C (82.4°F) inside; Liitokalas just switch off, a 12V 2A transformer just burnt out. So I'm switching power sources to two used PC PSUs which can output 12V at 7A each and I'll use them outputting 4A. Added big external fans.
- My cells come from different sources: two vendors (500+400 cells) and notebook batteries (250 cells). I want the four 14s20p batteries to have the most similar cell distribution possible, so I won't only divide cells by capacity and IR but also by model. For e.g. I have 200 Samsung 22F and 200 UR18650AA Sanyos: I'll divide them equally in the 4 packs, 50 Samsungs each and 50 Sanyos each.
- Final choice for series connections: nickel plates, strips, copper busbars? First choice is 16mm2 copper busbars for each battery, cells fused with 35AWG tinned copper, spot welded. Haven't got to test spot welding again (maybe I'm too scared after my last test LOL), if that fails I'll go for welding (I love welding!).
- I made the cooling/heating system with ESP8266 and got the DS18B20s working in OneWire configuration; an ESP8266+14 DS18B20 for each 14s20p battery; fans and Peltier cell switch on/off when temperature thresholds are reached; using IRFZ44N for giving them 12V current (I might use two MOSFETs because they get terribly hot with all the heatsink). I'll mount two cooling/heating systems (primary and backup) because temperature is critical. Looking for any other possible SPOF (single point of failure). So 12V power source for the system will be double, too: my old small solar system as primary source, grid as second source.
On the left ESP8266, center MOSFET with heatsink for powering cooling, in front of MOSFET three small DS18B20 temp sensors.
Peltier cell 12V 3A; I'll try cooling using this and a set of fans to distribute cool air.
- This heat is disrupting my chargers LOL today it's 36°C (96.8°F) outside and 28°C (82.4°F) inside; Liitokalas just switch off, a 12V 2A transformer just burnt out. So I'm switching power sources to two used PC PSUs which can output 12V at 7A each and I'll use them outputting 4A. Added big external fans.
- My cells come from different sources: two vendors (500+400 cells) and notebook batteries (250 cells). I want the four 14s20p batteries to have the most similar cell distribution possible, so I won't only divide cells by capacity and IR but also by model. For e.g. I have 200 Samsung 22F and 200 UR18650AA Sanyos: I'll divide them equally in the 4 packs, 50 Samsungs each and 50 Sanyos each.
- Final choice for series connections: nickel plates, strips, copper busbars? First choice is 16mm2 copper busbars for each battery, cells fused with 35AWG tinned copper, spot welded. Haven't got to test spot welding again (maybe I'm too scared after my last test LOL), if that fails I'll go for welding (I love welding!).
- I made the cooling/heating system with ESP8266 and got the DS18B20s working in OneWire configuration; an ESP8266+14 DS18B20 for each 14s20p battery; fans and Peltier cell switch on/off when temperature thresholds are reached; using IRFZ44N for giving them 12V current (I might use two MOSFETs because they get terribly hot with all the heatsink). I'll mount two cooling/heating systems (primary and backup) because temperature is critical. Looking for any other possible SPOF (single point of failure). So 12V power source for the system will be double, too: my old small solar system as primary source, grid as second source.
On the left ESP8266, center MOSFET with heatsink for powering cooling, in front of MOSFET three small DS18B20 temp sensors.
Peltier cell 12V 3A; I'll try cooling using this and a set of fans to distribute cool air.