John Frum
Tell me your problems
- Joined
- Nov 30, 2019
- Messages
- 15,233
This is my cpap battery.
2x dissimilar 30ah lithium batteries in parallel for ~532.8 usable watt hours.
Each battery has a separate port bms but I am charging through the discharge port because they are on the same bus.
I had a fancy setup with a double pole double throw relay but the coil didn't de-energise fast enough so I went with the simpler solution.
Last night my cpap machine drew ~125 watt hours with humidity set to 4.0 so plenty o'battery.
The button on the front bezel controls the atx power supply via the ps_on pin which in turn charges the batteries.
There is no charge termination logic so I charge the batteries to 12.2 ish to minimize the angry pixel stress.
2x dissimilar 30ah lithium batteries in parallel for ~532.8 usable watt hours.
Each battery has a separate port bms but I am charging through the discharge port because they are on the same bus.
I had a fancy setup with a double pole double throw relay but the coil didn't de-energise fast enough so I went with the simpler solution.
Last night my cpap machine drew ~125 watt hours with humidity set to 4.0 so plenty o'battery.
The button on the front bezel controls the atx power supply via the ps_on pin which in turn charges the batteries.
There is no charge termination logic so I charge the batteries to 12.2 ish to minimize the angry pixel stress.
