Rechargeable: Difference between revisions
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(Created page with "==Rechargeable batteries== Rechargeable batteries are popular with torch applications, because of the oftentimes relatively high current draw, compared to electronic goods such ...") |
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==Torch circuitry== | ==Torch circuitry== | ||
Three cells seem to work better in many flashlights. This is because most bulbs, especially LEDs, are designed to operate in the 3-4v range. 3 cells * 1.2 = 3.6v. No conversion circuitry is therefore required in 3 cell torches. The bulb can be powered directly off the battery cells. | |||
==Chargers== | ==Chargers== | ||
A good charger will use an appropriate charging rate (15 minutes is not appropriate), charge each battery individually, and will cut off when the battery is full rather than just after some period of time. It is very hard to find such a charger in stores. See [[Chargers]] for more information. | |||
==Battery types== | ==Battery types== | ||
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===Lithium Ion (Li-ion) - 3.7V/cell=== | ===Lithium Ion (Li-ion) - 3.7V/cell=== | ||
'''Important:''' ''***These are not the same as [[ | '''Important:''' ''***These are not the same as [[Primaries#Lithium|disposable lithium batteries]] sold by Energizer (Energizer e2 or Ultimate Lithium), Saft (who make it more confusing by selling 3.6V lithium cells that are not rechargeable), and other companies since those can not be recharged and will explode if you try it ([http://www.candlepowerforums.com/vb/showthread.php?t=250219 example]).***'' | ||
Lithium ion batteries are typical in mobile phones, where they offer higher density of charge storage. In other words, more amps can be stored in less size and weight. They can also be referred to by the chemistry of the anode ( | Lithium ion batteries are typical in mobile phones, where they offer higher density of charge storage. In other words, more amps can be stored in less size and weight. They can also be referred to by the chemistry of the anode (positive) which is lithium cobalt oxide (LiCoO<sub>2</sub>). They do not suffer from the "memory effect." However, they cost more, and are not as long established as the older AA, C, D, types typical in torches. | ||
Because of the higher voltage, Li-ion cells can only be swapped for NiMH or alkalines if the device manufacturer recommends it (Be careful! A fully charged li-ion battery has 3 times the voltage of a NiMH cell). Some flashlights that use two CR123A batteries can take a single 18650 battery (though this battery is wider than CR123A cells) which offers substantially more capacity than the two smaller cells together. | Because of the higher voltage, Li-ion cells can only be swapped for NiMH or alkalines if the device manufacturer recommends it (Be careful! A fully charged li-ion battery has 3 times the voltage of a NiMH cell). Some flashlights that use two CR123A batteries can take a single 18650 battery (though this battery is wider than CR123A cells) which offers substantially more capacity than the two smaller cells together. | ||
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===Lithium-Polymer (Li-Poly) - 3.7V/cell=== | ===Lithium-Polymer (Li-Poly) - 3.7V/cell=== | ||
Offers about a 20% increase in charge density over Li-ion, but again, offset by cost. | Offers about a 20% increase in charge density over Li-ion, but again, offset by cost. These batteries are usually rectangular in shape and are used more often in MP3 players and cell phones than flashlights. | ||
===Lithium Iron Phosphate (LiFePo4) - 3.3V/cell=== | ===Lithium Iron Phosphate (LiFePo4) - 3.3V/cell=== | ||