Find the 20W you're leaking
Ten minutes. Often worth a whole battery.
Ten minutes. Often worth a whole battery.
Waking to a lower state of charge than the math predicts is one of the most common off-grid complaints. Usually there's a phantom load.
A phantom load is something drawing power while you believe everything is off. Individually small. Around the clock, real capacity.
The usual suspects: an inverter left on. Stereo memory circuits, backup cameras, alarms. A propane/CO detector — necessary, keep it, but count it. Chargers with nothing plugged in. A fridge control board in standby. Router and cell booster left on overnight.
How to find it in ten minutes: 1. Turn off everything you believe you can 2. Watch the current reading on your battery monitor — this is where a shunt earns its cost 3. Whatever remains is your phantom load. Multiply by 24 for daily cost. 4. Pull fuses one at a time and watch the number drop
No shunt? A clamp meter on the main negative does the same job.
The Power Sizer turns your real appliance loads into a full spec — battery bank, solar array, controller, inverter and roof space — then matches it to gear that actually fits the number.
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