Charging the GPSMAP 378/478Before using the GPSMAP 378/478, you might need to chargethe battery. Plug the power cable into an external power source tocharge. You can use the unit while it is charging.To charge the unit’s battery:1. Lift the rubber weather cap to expose the power connectoron the back of the unit. See the image on page 1 forconnector location.2. Align the notches and push the plug into the connector untilfully seated.3. Plug the 12-Volt adapter into an available AC outlet, orcigarette lighter receptacle if you have a cigarette lighteradapter. Use care when routing the cable; make sure it doesnot interfere with vehicle operation. The unit begins chargingas soon as external power is applied.TIP: Placing the unit in Charge Mode charges the unit morequickly than when the unit is turned on, and reduces draw on thevehicle/vessel battery.When you turn on the GPSMAP 376C the power source indicator onthe GPS tab shows the unit is operating off battery power ( ),that the unit is charging ( ), or that an external power source isin use ( ).Using Charge ModeIf you want to charge the battery when you are not using the unit,you can put the unit into Charge Mode.NOTE: While in Charge Mode, the GPSMAP 378/478 draws asmall amount of current from the vessel/vehicle battery. To avoiddischarging the vehicle’s battery, disconnect the external powercable from the unit when not in use for several days.Over time, you might notice that the lithium-ion battery in the unitis not holding a charge any more. This is common for lithium-ionbatteries. Contact Garmin or your Garmin dealer to order a batterypack replacement if you are experiencing charging issues.2 GPSMAP 378/478 Owner’s ManualgettIng stArted > chArgIng the gPsMAP 378/478
