The most likely reason for an ELF to stop charging in direct sunlight is for the battery connection to become unseated. First, check to see if the battery has become unplugged by checking the connection under the dashboard of your ELF.
If this is the case, then plug the black battery connector box into the respective black connector box on the ELF. Insert the connector until you hear a click, make sure that this connection is firm and snug, and the problem should disappear.
If the battery is fully plugged in and the ELF still won’t charge in sunlight, then the ELF may have blown the MPPT fuse. To determine this, place a towel over the solar panel and turn the ELF off at the key switch. You should see one of the three indicator lights on the black box behind the key switches blink green slowly. If this is not the case and your battery is charged and plugged in, then your MPPT solar controller has blown a fuse.
To remedy this, open the black box with the three indicator lights situated behind the key switch. In it you will find the solar controller. Open the solar controller, unscrewing the screws, and you should see a red two-pronged fuse. Replace the fuse and screw the cover of the solar controller in place.
If the MPPT fuse is intact and the battery is plugged into the ELF but the battery still will not charge in sunlight, then the solar panel may be suspect. In this case, please review this video in order to test the functionality of your solar panel.