Within the wide range of batteries on the market we can differentiate two large groups, disposable batteries and rechargeable batteries.
Disposable batteries are those that only allow a single use and when they are exhausted they can not be recharged. These batteries can store their energy for years.

Rechargeable batteries are those that can be recharged once exhausted. This type is losing charge when they are storedaccording to voltage. The most common we can find them of 1.2V and 3.7V

As a last point you have to take into account that lithium batteries, Lipo, Life etc. Due to its composition, specific loaders should be used.

The COB Led (chip on board) is a plate (A) with a concentration of LEDs in the form of matrix (B) covered with a special silicone.
This type of led due to its design and installation allow to dissipate in a more efficient way the heat generated by the lighting.
It must be taken into account that the heat is generated in the opposite direction to the light and a low dissipation will cause the led to work in less optimal conditions.thus, its useful life.

Thanks to this design the Led COB is designed to work for long hours.
Its beam of light is multidirectional, so it is a type of diffuse light without dazzling at a point, achieving up to 160 º opening light and have a superior performance to the type of LED SMD.

Its manufacturing cost is 20% lower than an SMD led and its technology offers a reproducible indexchromatic ion (CRI) much higher, getting a better appreciation of colors.

In short, the COB LEDs can produce more lumens using much less energy than the rest of the LED technologies.