I have used a single batteryspace.com's 650mAh RCR123 Powerizer to power a KL4, and they work just fine. They can handle more than 1.3 amps, but you will find that 1.3amps is just about what the KL4 will need for good regulation. Remember that you are dealing with unprotected RCR123's, so as soon as the light dims, switch out the battery. Dimming will occur before the battery is too depleated. I also use 2 of these Powerizers to power my A2.
Bill