EY9021 PANASONIC Power Tool Battery Pack - Replacement

There are 3 batteries can replacement for PANASONIC EY9021 battery made from the high quality cells and parts in our store, you can find some different features from them, the EY9021 Power Tool Battery is designed to be 100% manufacturer compatible with PANASONIC models.

Image	Type	Capacity	Volt	Color
	Ni-MH	2200mAh	2.4V	Grey
	Ni-MH	3000mAh	2.4V	Grey
	Ni-Cd	2400mAh	2.4V	Yellow

Battery Knowledge

• What is rechargeabel battery self discharge?
  Primary battery or full charged secondary battery, when put aside for a period, it s capacity will decline or lose,this phenomenon calls self discharge that is electricity flee away.It is decided by the inner electro-chemistry system, similar to water leakage from pond or reservoir.
• What is the ambient temperature affects the battery performance?
  Low temperatures (e.g. -15^oC) will obviously reduce Ni-Cd and Ni-MH battery discharge rate. At -20^oC electrolyte is at its freezing point, charge speed will greatly slow down. At low temperature (under -15^oC) charge will raise the internal gas pressure and probably unseal the safety vent. Ambient temperature of 5^oC to 30^oC is the best range to get effective charge. Generally with temperature rising charge efficiency will become higher. But when the temperature rises to 45^oC or higher, the materials performance in the battery will be degenerated and battery service life will be shorten greatly.
• How can rechargeable batteries be connected?
  The rating for rechargeable battery NEW!! Battery Chemistry F.A.Q - Here we discuss different battery designs currently used, some of the chemistry involved, and advantages and disadvantages of each design. We have also included some useful definitions and a list of parameters to guide you in matching your battery requirements to a specific battery design.