What are the differences between primary and rechargeable lithium batteries?
The main difference is that primary batteries are used once and thrown away while rechargeable batteries can be used and recharged hundreds of times. This can make a dramatic difference in the overall cost of operation of your flashlight. If you assume $1.50 for primary batteries and $36.00 for two rechargeable batteries and the charger, the rough break even point is 24 battery changes. Rechargeable batteries have a lower absolute power capacity at lower power settings than a primary battery. However, at the end of the day, you can swap a partially used rechargeable battery for a fully charged one so you always leave home with a full capacity battery. People that use primary batteries usually find it too expensive and wasteful to put in fresh batteries until the current battery is mostly depleted. Thus primary battery users often leave home with less actual capacity than if they had used rechargeable batteries. At the highest power settings, the absolute capacity of a primary battery i
