Discussion Overview
The discussion centers around the continuous wattage that can be drawn from a 12V lantern battery, particularly in the context of powering a C-Pap machine during a blackout. Participants explore the battery's capacity, voltage drop under load, and the implications for using such batteries for high-wattage devices.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
- Mathematical reasoning
Main Points Raised
- One participant calculates that two 12V lantern batteries in series provide 172.8 watt-hours, suggesting this could power a 90W device for approximately 1.92 hours.
- Another participant notes that a single lantern battery provides 86.4 watt-hours, which can be distributed in various ways depending on the load.
- Concerns are raised about voltage drop under load, with questions about how low the voltage can go before a device stops functioning.
- A participant shares an experience where drawing 90 watts from a different battery caused it to shut down, indicating potential issues with high wattage draws.
- There is discussion about the concept of "peak output" and the need for a battery to have a peak power output significantly above the required wattage to avoid stressing the battery.
- Participants express difficulty in finding reliable datasheets for consumer batteries and the importance of understanding battery chemistry and specifications.
- A link to a datasheet is shared, but concerns are raised about the load specifications not meeting the participant's needs for the C-Pap machine.
- Another participant mentions that most CPAP machines require between 30 and 60 watts but need about 100 watts to start, complicating the power requirements further.
Areas of Agreement / Disagreement
Participants do not reach a consensus on the continuous wattage that can be reliably drawn from the lantern batteries. There are multiple competing views regarding voltage drop, peak output, and the suitability of the batteries for high-wattage devices.
Contextual Notes
Limitations include uncertainty about the specific chemistry of the batteries, the lack of detailed specifications in consumer datasheets, and the potential for voltage sag under load, which could affect performance.