Zapro:
I would be very surprised if the pointer runs on 5V - there is not "standard" chemistry that will give you 5V.Are you sure it's not running at 4.5V from three alkaline buttons cells in series?
// Per.
On fresh alkaline batteries, you get more than 1.5v out open circuit - my guess is he took a brand new one and cracked it open and measured the open circuit voltage.
It's really common to rely on the internal resistance of coin cell batteries for applications like this (those little keychain flashlights usually just have an LED and coin cell inside, with one lead against one side, and the plastic switch pushing the other lead against the other side of battery when turned on). Just add a series resistor. 220 ohm would be a good starting point. Maybe 330 for good measure.