Jayco Hummingbird 2018 Owner'S Manual Download

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Section 6: Electrical System

Dry Camping

The auxiliary battery should be fully charged prior to dry camping. If the auxiliary battery is
not being recharged and power is being drawn from it, it will eventually discharge. A battery
will discharge at a faster rate as its energy level becomes depleted. Plan your electrical usage
accordingly. You can test the auxiliary battery voltage using a volt-ohm meter (customer
supplied).

A fully charged auxiliary battery will read 12.7 volts DC and 1.265 specific gravity at 80°F

(32°C). The auxiliary battery is considered discharged at 11.89 volts, and dead at 11.65
volts. If the voltage drops below those levels, irreversible damage can occur. Typically, a
deep cycle battery has an amp-hour rating of 75-100 amps.

If you run the furnace and refrigerator simultaneously, you will be using approximately
(12.0 + 3.0) 15.0 amps per hour. This does not include any 12-volt lights, or any other 12-
volt component. If the furnace and refrigerator in this example operated constantly, a 75
amp-hour battery would become fully discharged in 5 hours.

The auxiliary battery should be installed in parallel with the battery in your tow vehicle.
When the 7-way trailer plug is connected, both batteries power the RV. Do not allow it to
discharge your tow vehicle battery below the level required to start the engine. To prevent
this from occurring, disconnect the 7-way trailer plug or install a battery isolator. When the
tow vehicle engine is operating with the RV connected, the tow vehicle charging system will
charge both batteries.

Replacement and Maintenance

Some equipment in your RV will draw small amounts of current even when turned OFF. To
prevent the auxiliary battery from being discharged when your RV is not connected to shore
line power, disconnect the auxiliary battery negative cable at the battery. During storage, it is
important to check the voltage monthly and recharge the auxiliary battery as needed. If you
remove the auxiliary battery from your RV, store it in a dry, cool area per the manufacturer’s
instructions.

When it is time to replace the auxiliary battery,

replace it with a Group 27 deep cycle

battery only

. Do not reverse the positive and negative battery cables (doing so will blow the

reverse polarity fuse(s) that protect the converter).

For more information

Please contact the battery manufacturer for additional information on the auxiliary batteries.

Battery Isolator For Your Tow Vehicle (customer supplied)

You may want to consider the installation of a battery isolator on your tow vehicle as a
convenience feature:

It receives current from the tow vehicle alternator and controls distribution of energy to
both the RV auxiliary battery and the tow vehicle battery.

It serves as a check valve to prevent energy from being drawn from your tow vehicle
chassis battery (so you can start your tow vehicle engine).

Your dealer can assist you with the selection, purchase and installation.