Ok, I figured that was the case. Do you think using one diode (would you recommend an LED?) would suffice?
Most LEDs drop 1.5 or more depending on their color type. A single silicon diode should be OK (say a 1N4001). From a HD44780 data sheet:
"The low power supply (2.7V to 5.5V) of the HD44780U is suitable for any portable battery-driven product
requiring low power dissipation."
Lefty