If you're looking for the most advanced smart charger available, the Xtar VP4 Plus Dragon has all of the latest features that discerning users need. This has four independent bays that can charge a wide range of both Li-ion and NiMH batteries. Multiple charge current modes allow you to choose the appropriate speed to charge your batteries, a much needed feature for portable power enthusiasts. The Xtar VP4 is also equipped with probes that allow users to test battery voltage, internal resistance and other vital information regarding various power cells. Charged batteries within the charger can even be used a power banks for mobile devices, utilizing a USB output port that is perfect for phones and tablet devices.