I edc a Jetbeam with a Ultrafire 14500 lithium. I've noticed a lot of posters are using Eneloops AA's. Are these batteries comparable? Could someone give me a quick rundown on the pro's and con's.
Hi, welcome to the forums. These rechargeable 14500's are the same size as AA batteries. Lithium batteries are 3x the voltage of Nimh's. 1.2v vs 3.6v. The chemistry they use is totally different. Ni-mh's are more forgiving when it comes to over charging and over discharging. Lithium's can become dangerous of they are not used properly. They can also be destroyed if they are discharged too much. The main advantage of lithium batteries is their energy capacity. UltraFire 14500 is rated @ 900mah (although capacity is likely over rated). 900mah x 3.6v = 3.2Watt hours. While eneloops are 1.2v x 2000mah = 2.4 Watt hours. The nice thing about 14500's is they are 3.6v the operating voltage of most LED's. So you could have a smaller flashlight operate off 1x14500 rather than the 3xAA's needed to achieve the 3.6v.
Eneloop Chemistry: Nickel Metal Hydride Used for: replacing Alkaline cells Nominal Voltage: 1.2V [1.5V peak] Nominal Capacity: 2000mah, 2.4WH
ANSI 14500 lithium ion Chemistry: LiCoO2 [] Used for: These 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. 17670 are the smallest cells I've seen in laptops. Advantages: No memory effect and longer storage life than NiMH Batteries. Relatively inexpensive, high current discharge [2C] for protected Disadvantages: unprotected cells are unstable and requires the user follow the rules of charging, damage will occur if overcharged or overdischarged Nominal Voltage: 3.6V [4.2V peak] Nominal Capacity: AW 14500s are 750mah, 2.7WH
Relatively inexpensive...Perhaps until the manufacturer fits the cells into a proprietary battery so that there can be a healthy markup on batteries and chargers.
I don't know anyone who would describe a mobile phone battery as inexpensive.
When you get into custom LiPo or prismatic Lithium cells, that is yet another subsection, and not inexpensive...but the topic was aboot (Canadian for "about") 14500.
Considering that one 14500 has the voltage of 3 x NiMH AA's, the advantage of a more compact energy density source, number of charge/discharge cycles, it is relatively inexpensive.
I recently got my very first 14500s and use them in my Xeno E03. Then I thought about the issue with over discharge and found this thread. I read that 14500s will easier damage by over discharge than NiMh.
Using a light which is unregulated I think I will risk to over discharge the 14500 cell without the lightmeter which can confirm the brightness drop.
If a fully charged 14500 starts with 4,2V it's natural that a noticable drop will be in the beginning until the voltage is ~3,7V. But after that, how large brightness drop is possible without damaging the 14500?
At one moment I suspected the brightness had dropped significantly and the lightmeter showed less than half of initial brightness, but still brighter than with AA. Then I recharged it. What is your way(s) to be sure to not overdischarge the 14500 cell?
The eye perception isn't always a sure method, and I can't always use the lightmeter.
Edit: this is my very first experience with Li-Ion batteries. I just read at some other thread that protected cell does mean it prevent the cell to be as well over-charged and over-discharged. That's good!
Without getting technical I use both(eneloop & Aw 14500) in my Spark ST5(single AA). Basically the 14500 run longer and the light is brighter in High mode. My light is current regulated, so I feel confident in running 14500!!
Li-ion: Higher voltage, somewhat higher energy density, and lighter.
Eneloop: Standard alkaline AA replacement alternative, safer to use, lower self discharge rate, higher capacity, longer cycle life expectancy, less likely to be damaged during use, safer to charge, and generally less expensive per cell.