Volt meter specs

Hi!
Im looking to buy a cheap inline volt meter on ebay. Just a cheap one along with the Turnigy that I have.
I have a 72V battery pack on my ebike.
This meter is rated 0-100V but Im confused about the "•Power Supply: DC3.0-28V"
Does Power supply mean that I cant go over 28V with my 72V battery, or is that voltage for someting else??

http://www.ebay.com/itm/Mini-3-Digital-0-36-Blue-DC-0-100V-Volt-Voltage-Meter-Voltmeter-3-28V-In-/231204273058?pt=LH_DefaultDomain_0&hash=item35d4d93ba2

Thanks in advance!!

I think the red wire is to power the meter with not more than 28V. More than that will blow it.
The white goes to your battery to measure voltage.
And both share a common ground.

yep the red wire is power, on mine the measured voltage leg is yellow.

So white wire goes to Positive on the battery?? Where does red wire go??

to whatever you use for the power supply.

You need a separate power supply for that meter. This one does not require a separate supply.
http://www.ebay.com/itm/Waterproof-Digital-Voltmeter-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-G9-/161078127200

Some meters require a different power supply to the voltage being measured. A dry cell battery should last for a long time especially if you make it switchable.