Zumio will get warm to the touch when charging. This is perfectly normal. This is warm for human touch at 105 Fahrenheit (40 Celsius) and perfectly safe for the unit. The charging method relies on 50-year-old NiMH (Nickel Metal Hydride) battery technology which is slower to charge than lithium and has a better safety record. The technology we chose is approved to fly on airplanes unlike other newer faster charging technologies based on lithium.
