atatistcheff
Solar Enthusiast
- Joined
- Sep 20, 2019
- Messages
- 176
I just finished building a LiFePO4 battery for a used APC UPS. I wanted a bit more runtime than the lead acid battery would provide but that's another story. I figured about 16Ah would do me fine and decided to go with Headway cells from batteryhookup.com. In reality, I've been bit by the lithium bug and just needed an excuse to build another battery!
The description is long and boring so if you just want to see it feel free to scroll down to the photos.
If you're not familiar with Headway these are LiFePO4 cells that look sort of like oversized 18650s. What makes them different than typical LiFePO4 though is their crazy C rating. It's on the order of 10C continuous and 25C for short pulses. That means an 8Ah cell can pump out 200 amps! I haven't personally tried it but there are Youtube videos of folks staring a car with four of these in series.
Well, I don't need that kind of power for the UPS but the Headways were cool and the price was really good on these "engineering sample" from Battery Hookup. I bought the plastic holders, bus bars and BMS on eBay. Total cost for the whole battery was about $180. It will run a 220W load for about 35 minutes (the UPS is only about 75% efficient so 35 minutes of runtime is about 90% of the battery pack capacity).
The pack is a 4s2p configuration, the BMS is rated at 60A continuous which is more than enough for the 720VA UPS. The BMS is a 3 wire and I have a separate LiFePO4 charger which I will connect to the BMS charge input. Charger and load use separate XT-60 connectors.
I plan to put it in a plastic ammo box and will probably add some external terminals that bypass the BMS. That way I could use this battery to start a car in an emergency. Heat has not been an issue with my testing. At the 3C discharge rate my UPS needs, the batteries and BMS are barely showing any signs of warmth.
Should have the box this week and I'll update with more photos.
The last photo compares the Headway 16Ah to my solar generator with a 60Ah Sinopoly pack from RUiXU. As you can see the Headway pack is nearly as large as the RUiXU battery so these aren't the most compact batteries out there. But they are cool none the less.
The description is long and boring so if you just want to see it feel free to scroll down to the photos.
If you're not familiar with Headway these are LiFePO4 cells that look sort of like oversized 18650s. What makes them different than typical LiFePO4 though is their crazy C rating. It's on the order of 10C continuous and 25C for short pulses. That means an 8Ah cell can pump out 200 amps! I haven't personally tried it but there are Youtube videos of folks staring a car with four of these in series.
Well, I don't need that kind of power for the UPS but the Headways were cool and the price was really good on these "engineering sample" from Battery Hookup. I bought the plastic holders, bus bars and BMS on eBay. Total cost for the whole battery was about $180. It will run a 220W load for about 35 minutes (the UPS is only about 75% efficient so 35 minutes of runtime is about 90% of the battery pack capacity).
The pack is a 4s2p configuration, the BMS is rated at 60A continuous which is more than enough for the 720VA UPS. The BMS is a 3 wire and I have a separate LiFePO4 charger which I will connect to the BMS charge input. Charger and load use separate XT-60 connectors.
I plan to put it in a plastic ammo box and will probably add some external terminals that bypass the BMS. That way I could use this battery to start a car in an emergency. Heat has not been an issue with my testing. At the 3C discharge rate my UPS needs, the batteries and BMS are barely showing any signs of warmth.
Should have the box this week and I'll update with more photos.
The last photo compares the Headway 16Ah to my solar generator with a 60Ah Sinopoly pack from RUiXU. As you can see the Headway pack is nearly as large as the RUiXU battery so these aren't the most compact batteries out there. But they are cool none the less.
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