What's eneloop?

eneloop is a totally new type of battery, which satisfies

in a unique way the needs and expectations of the consumers.

The needs of the consumers

Consumers would like to have a battery, which

• can be used right after the purchase
• has a high performance
• has a long shelf life with no loss of energy
• can be used everywhere
• is cheap in purchase and usage
• is environmental friendly
• is easy to use
  
  

Spoilt for choice

So far these requirements could not be satisfied by a single type of batteries. 

The consumer had the choice between disposable batteries or rechargeable batteries.

Disposable batteries have several advantages : 

• they can be used immediately
• they have a long shelf life with low loss of energy
• they are rather cheap in purchase
• they are easy to use and no charger is required

These advantages however, had to be seen alongside several clear disadvantages. 

Disposable batteries

• can be used only once and therefore mean substantial waste and risk for the environment.
• have to be purchased over and over again and are therefore expensive considering the life-time of your equipment.
• are not quite powerful enough in certain applications ( like digital cameras )
• are being offered in many varieties and special application-specific types, which confuses the consumer. 
  
  

The classical advantages of rechargeable batteries are:

• high performance, especially if high discharge currents are required ( like in digital cameras )
• cheap in use, because they can be recharged many times.
• environmental friendly, because one rechargeable battery replaces 1000 disposable batteries.
• good performance at low temperatures.
  
  

Given these advantages, there were however also some disadvantages, which made consumers reluctant to exchange disposable batteries by rechargeable batteries.

• After purchase, rechargeable batteries have to be charged before they can be used. 
• Rechargeable batteries lose the stored energy rather fast.
• The state of charge is hard to determine.
• Continuous charging or frequent charge ( without complete discharge ) can destroy the battery.
• Proper charging is complicated for an average consumer
• The charging takes quite long and rapid chargers are expensive. 

All these negative attributes have one root-cause: self discharge. 

Self-discharge means, that a charged battery slowly discharges itself without any equipment consuming any current.

This is the reason for rechargeable batteries being sold in discharged state. And this is the reason for that keeping charged batteries for some time did not make any sense. When you needed them, the energy was gone.