About 9 Volt, AAA and AA Battery Chargers

 There are 3 main types of battery chargers:

• Slow Battery Charger – This uses a fixed charge of about 0.1C* or 1/10 of the battery’s rated capacity and is also known as an overnight charger. This takes about fourteen to sixteen hours to charge a battery. These slow battery chargers are usually associated with CD players, cordless phones and other similar items and NiCd, NiMH and Li-ion packs.
  
  
• Quick Battery Charger – The quick battery charger charges at a medium speed and is priced in the mid range. Charge time for this charger is between three and six hours. The battery switches to trickle charge when charging is complete. This charger is associated with the nickel-based or lithium batteries used in laptops, mobile phones and camcorders.
  
  
• Fast Battery Charger – The charge rate for this battery charger is 1C and it can charge an empty NiCd or NiMH battery in an hour or so. The battery charger needs to be able to accurately detect a full charge since the charger switches to topping and then trickle charge once the battery is fully charged.

Some Rules of Thumb for Battery Chargers:

• A battery charger which is designed for NiMH can also charge NiCd batteries, but this doesn’t work in the reverse. A charger for NiCd would overcharge and damage an NiMH battery.
  
  
• Nickel-based batteries are better charged with fast battery chargers because these chargers reduce crystalline formulation or memory.
  
  
• Lithium and nickel-based batteries cannot normally be charged in the same charger since they require different charge algorithms.
  
  

NiMh rechargeable batteries are the least damaging to the environment and that is why only NiMh batteries are available on this website. We sell 9 volt, AAA and AA battery chargers as well as batteries.

Battery chargers for NiMH batteries are similar to NiCd chargers but have more complex circuitry. For one thing, NiMH chargers have a tiny voltage drop when the battery is fully charged. When the voltage drops, this indicates to the charger that the battery is fully charged, which is known as Negative Delta Voltage or NDV. NDV is negligible at charge rates beneath 0.5 C and high temperatures. In addition, when battery cells are aging and degenerating, this further diminishes the already small voltage delta so that the charger cannot detect when to stop charging.

Cheaper NiMH battery chargers may not charge the battery fully since it may sense that the battery has been fully charged after a set voltage peaks and drops or a set temperature is reached. People often buy these battery chargers because of their low charge times and relatively inexpensive prices. However, some of the ultra fast chargers do not apply the full charge on the battery.

These points having been explained, all rechargeable batteries are cheaper in the long run and are kinder to the environment than disposable batteries. Some rechargeable batteries, like the AAA, AA and 9 volt batteries sold on this site, come in the same sizes as disposable batteries. Rechargeable batteries obviously require a higher investment to start off with, but the cost of charging is quite low and they can be used multiple times.