Recharging Alkaline Batteries : Fact or Fiction?

Yes, alkaline batteries can be recharged. However, it is not considered to be cost effective and does have some risks. Recharging any battery can cause the production of gas within the battery. Since an alkaline battery is normally sealed, very high pressures can be created within it. This can rupture the seal, resulting in leakage of the contents or even explosion. Rechargeable batteries including RAM (rechargeable alkaline manganese) batteries are specially designed to help reduce this risk.

Recharging alkaline batteries was first introduced in the early 1990’s. It was introduced as an alternative to the Nickel Cadmium (NiCad) rechargeables. The advantages then were higher voltage (a full 1.5 volts), slow self-discharge, and no “memory effect”. When Nickel Metal Hydride (NiMh) batteries became available in the early 2000’s, the advantages of recharging alkaline batteries diminished. Nimh batteries had a higher capacity, more recharge cycles, and little or no memory effect compared to the NiCad batteries. The advantage of recharging alkaline batteries has further decreased with the introduction of “Hybrid or Precharged batteries”. Hybrid batteries are Nimh batteries with some changes in their construction resulting in a slightly lower capacity than the standard NiMh, but adding the benefit of a slower self-discharge. With the decreased benefits, most manufacturers have discontinued their RAM batteries and chargers. However, RAM and alkaline batteries are still available and are considered to be the most environmentally friendly. The most common manufacturers that offer RAM batteries and chargers are IGo, AccuCell and Pure Energy. Here are the main pros and cons of alkaline and RAM batteries.

Pros:

• Pre-charged
  
• Slow self-discharge
  
• More environmentally friendly (fewer toxic metals)
  
• Full 1.5 volts when new
  

Cons:

• Long recharge time (10-16 hours)
  
• Higher risk of leakage when charging and while in use
  
• Must be recharged after only partial usage (the less usage before recharging the better)
  
• Noticeable decrease in run time after each charge cycle
  
• Requires a charger specifically designed for alkaline batteries
  
• Fewer charge cycles (based on a discharge to < 50% of its usable capacity)
  
• Poor performance in high drain devices