This 2S battery has a capacity of 550mAH, and is equipped with a universal JR-type discharge connector (plus a balance connector). It's ideal for powering the control-electronics of a model airplane, helicopter, or truck because it outputs clean DC voltage. This is an especially important consideration with electric-powered models where the ESC has a BEC (Battery Eliminator Circuit). Why? Essentially because in comparison to the perfect DC voltage of a LiPo battery pack, the synthetic voltage created by any BEC costing less than $5000 is just garbage! Learn more here
With the advent of surface mount technology, the reliability of servos and receiver has become exponentially greater. Basically, crashes that don't involve pilot error are usually due to a battery
pack or switch failure. This 7.4VDC 2-cell LiPo battery pack aims
to increase reliability by reducing cell count - and by adopting proven lithium battery chemistry. The benefit of lithium chemistry is greatly increase current handling capability, which is important due to the demands imposed by digital servos.
Traditional receiver battery packs rely on NiCd/NiMH chemistry. The packs consist of 1.2V cells and depending on whether they are in a 4-cell or 5-cell configuration, output 4.8V or 6.0V. The beauty of the lithium chemistry battery (like what's used in mobile phones, laptops, and for powering the propulsion motor of a model) is each cell outputs 3.7V. Using only 2-cells results in 7.4V, and higher voltage, due to Ohms Law, means current goes down. The practical effect of this is better performance at the servo and reduced loses due to extensions and results in fewer interconnections for greater reliability, e.g. a win-win!
further advantage of the lithium chemistry is a greatly increased
ability to respond to the current demands. basically, this 35C pack can
deliver significantly higher current. This is important is with digital
servos because they may draw a lot more current than old-school analog
servos. Plus, if you're an aggressive pilot, e.g. flying 3D (or are a
competition driver) when the servos are moving more and deflecting
further, they're drawing more current. Bottom line? A higher C-rating is
a big deal.
Finally, if you'd like some Pro Tips on LiPo battery care, read this:
Best practices regarding the care and handling of LiPo battery packs.