i want to say that the 18650 also needs a aleeve around the battery as its diameter is less than the aaa. Im sure you can make something for it... a little cardboard taped to teh side of the 18650 to keep it centered on the light contacts. brightess wise you could put 3 li on batteries in the light to see what teh 3.7 18650 would look like.
Incorrect, 18650 battery means the battery cell is 18mm in diamter and 650mm in length. It is quite a bit bigger than AAA. In fact, its is quite a bit bigger than AA as well.
---------- Post added August 7th, 2014 at 01:13 AM ----------
Lithium Energizer AAA batteries (from what I could find) have about 1250mAh of discharge (burn time). Eagletac and Panasonic both have 18650 Lithium-ion batteries with 3400mAh ratings (this equates to a longer burn time). You should be able to find the 18650s online but here is a link to the eagletac:
https://www.eagletac-usa.com/products/productList.aspx?uid=5-6 With the 18650 you need to buy the recommended charger.
Also incorrect. The unit mAh is NOT burn time, it is a unit for energy content at given voltage. A 3400mAh means if you are to draw 3400mA, the battery will last 1 hour. But if you draw half the current, 1700mAh, the battery will last 2 hours.
---------- Post added August 7th, 2014 at 01:30 AM ----------
I just bought my first
LED light that can use 3 AAA's or 1 18650 battery. I've tried to find comparisons but EE is not my forté. Can someone explain the benefits to me of using either types of batteries? I'm guessing that AAA's are a bit more expensive in the long run. What about power? Will the power be the same on either set of batteries? I'm really interested in length of burn time vs power on a set of batteries. The longer the burn time, the better I like. I know that 18650's are not cheap which brings me to my next question...
Where can I get some inexpensive but good 18650's and a charger? I have read some threads that recommend Panasonic 18650B batteries. Any opinions? Also, where is a reputable place online to buy?
Thanks in advance. Diving questions, I'm ok at. Batteries, not so much!
dd
Currently, 18650 battery has much higher energy content than AAA battery. Not only 18650 has higher mAh number, it also operate at a much higher voltage, 3.7V vs 1.5V. When compare the total engery contained in a battery(ies), take the operating voltage x mAh.
A 18650 with 3400mAh has total engery of 3.7V x 3400mAh = 12580mWh (mill watt hour or mill Joules) of energy. Now this is energy, it basically tell you at a given brightness, how long the light will last.
The second part of it is power. It has to do with how much current the battery can delivery at sustained load. Take the same 18650 3400mAh for example. Again 3400mAh mean if you draw 3400mA, it will last 1 hour. mathematically, it also means if you draw 34000mA, it will last 0.1 hours. But 18650 battery is NOT capabile of delivery 34000mA. So there is a spec'ed number for this: max sustain load current.
Having that the above said, 18650 is overall a much better battery platform. It is capable of delivering much high load current than AAA (brighter lights), operate at a higher voltage (so you don't need so many in series), and contain much more energy. 18650 does cost more, but has become very affordable these days.