There are a lot of white lights, lasers and illuminated optics on the market that use the small, powerful 123A batteries.  These batteries work great, but they tend to be expensive.
Surefire is now offering a rechargeable 123A battery kit. Â The kit includes two rechargeable batteries, the charging unit and power adapters for both home (110v AC) and the car (12v DC). Â MSRP on the kit is $29 and additional batteries can be bought for $12/pair.
Rechargeable 123A batteries can be used hundreds of times, offering a significant cost savings over their lifetime.  However, the rechargeable batteries do not hold as powerful a charge, meaning that runtime is only about 50% of the normal runtime on typical non-rechargeable 123A batteries.