EFOY 80 Fuel Cell (12 V configuration) connections

This entry represents EFOY 80 configured for a 12 V battery. The unit supports other settings, but a drawing must use the configured voltage consistently. Its maximum rated output is 40 W; the published 3.8 A is a peak current at 10.5 V, not 3.8 A at every battery voltage. Rated-output simulation is an operating point, not guaranteed daily generation. The data sheet permits declining output with age and specifies minimum bank capacities of 40 Ah lead-acid or 20 Ah lithium. See ratings and aging qualification, PDF p. 1.

The charging harness has separate POWER+ and POWER− conductors and a SENSE+ / SENSE− pair. The sense wires measure voltage at the battery so cable drop does not mislead charging control; they do not carry the main output. Preserve both circuits and polarity. Fit the documented 20 A power fuse and 2 A sense fuse near the battery. Those fuse ratings do not describe fuel-cell output current. See battery connection, PDF p. 29.

Use at least 4 mm² power conductors for extensions up to 10 m and 6 mm² for 10–15 m, following the manual's extension arrangement. The sensor pair is 0.75 mm² in the supplied harness. This is a ventilated fuel-burning appliance: provide incoming air, a separate exhaust-heat outlet and the supplied exhaust-gas hose led outdoors. Keep the exhaust-gas route unblocked and draining as specified. See air and outlet requirements, PDF p. 13 and exhaust routing, PDF p. 23.

Select the battery type and permitted charge settings, connect a genuine EFOY fuel cartridge, and verify measured voltage before automatic charging. Temperature, battery demand and aging change output. Sleep mode still supports battery protection and automatic antifreeze behavior. Below about 3 °C, keeping a suitable battery connection and fuel supply available is part of the manufacturer's frost protection procedure; an isolator that removes power defeats it. See frost-protection notice, PDF p. 1.