Identifying + and - terminals on a battery

Hi All,

I've got a Dell 20qf0 battery (for a Streak) I want to charge using a universal battery charger, which means I need to know which are the positive and negative terminals on the battery. Unfortunately neither the battery nor the phone are marked with polarity.

Does anyone know, or have any suggestions for figuring out which terminals are which; OR if there will be horrible concequences for guessing and getting it wrong? (I understand it's usually the outside two; but I know my Galaxy S2 battery is second and fourth).

Thanks!