Re: How to Pick a Digital Camera

• First of all, you must get to know your device:
• What is device's input voltage? ( V)
• What is its power consumption ( Wattage ) ?
• What is Maximum current drain ( A) ?
• What is your expected running time by a battery pack ?
• Decide battery pack voltage you will choose
• Battery pack voltage must be equal or a little higher than your device's need.
• If you need a exact voltage, which battery pack can not provide, you may consider to use a DC-DC regulator
• Decide Battery pack's Capacity  ( mAh or Ah)
• Battery capacity is depended on how long you need to run your device ( hours ), which can be calculated as the follow:
• ( Ah) = Device's Wattage (W) x Time to run ( Hours) / Battery Voltage (V)
• For example, if using a 12V battery pack, and run 10W DC device for 10 hours, you need choose a battery pack with capacity > 8.3Ah, e.g

( 10x10)/12 = 8.3

• 1000 mAh = Ah,  higher mAh will provide longer running time.
• Decide Battery pack's Max. discharging current
• Before order battery pack, you must pay attention on battery pack's Max. discharging rating on the specification or description. Please don't think any battery can take any current drain.
• You shall know your device's max. discharging current. If you don't know , you must measure it by a multi-meter.
• The battery pack's Max. discharging rate of the chosen Battery must be higher than that device requires
• Choose Li-Ion, NiMH or Lead acid battery?
• All types of rechargeable battery will work for you. Question is size and weight. The table below lists the advantages and disadvantages of these batteries for your reference

Chemistry	Cost	Weight	Temp	Cycle	Shelf Life	Volts
			( ℃)	Life	(months)	per cell
Lead Acid	$$	Very Heavy	-65 to 80	300	12	2.0
Nickel Cadmium	$$	Heavy	-20 to 65	500+	6	1.2
Nickel Metal Hydride	$$$	Moderate	-10 to 65	500	12	1.2
Lithium Ion	$$$$	Light	-20 to 60	500+	12	3.7
Lithium Polymer	$$$$$	Light	-20 to 60	500+	12	3.7

• Li-Ion batteries has the highest energy density ( mAh/weight), and become more and more popular. However, Li-Ion may explode and cause a fire if it dose not use properly.
  
• In current stage, we always suggest customer to use NiMH battery pack for high current application ( < 1C rate ), not Li-Ion , because Li-ion  protection in high current application still is not matured yet
• Choose a Battery Charger
• Please always follow our suggestion to choose a smart charger. So called smart charger must has automatic power cut-off function when battery is full.
• Never use NiMH battery charger for Li-ion battery pack, it will cause battery exploded
• Always charging your battery with attention, and put battery in a fire-proof container ox box to avoid any accident.
• Understand risk to use NiMH and Li-ion battery. Please read our safety warning before buying a battery

Camera Battery Recommendation:
Canon NB-1LH
Canon NB-2LH
Casio NP-20