My only experience with batteries in flashlights so far has been with AA and AAA. It’s all I’ve ever really needed, but I keep seeing more lights with high performance using batteries like 14500 and 18650. I’ve thought about trying an 18650, but it looks like I’d have to get a new charger just for that one battery. It appears that the 14500 is the same size as the AA. So here are my questions.
1. Is the 14500 the same as AA in size, except for being 3.7 volts (and sometimes 3.2 volts) instead of 1.5, and also being lithium instead of alkaline?
2. Can I use my NiMH battery charger to charge 14500s?
3. Can flashlights made for 14500s also use AA alkalines and NiMH batteries?
4. Can flashlights made to use 2 alkalines be used with 1 14500 (using a spacer, of course)?
5. Can an 18650 be charged in a charger made for AA NiMH batteries? Or are they too big to fit in that kind of charger?
1. Yes (but 14500s are Lithium ION (Li-Ion), different to Lithium. You can get 1.7v Lithium primaries the same size).
2. No, the voltages, charging criteria, and detection are all wrong.
3. Only if the driver is designed to do so, a 14500 will supply a voltage needed to drive an LED but you need to boost NiMH and Alkalines to reach those voltages, so if the driver can’t boost NiMH/Alkalines won’t work.
4. Not always, a 2xAA driver will be a boost driver, it may not be designed to work with the voltage of a 14500. But it’s not a given.
5. No, the voltages, charging criteria, and detection are all wrong. (Same as 2.)
Chargers can generally take different battery sizes but not different battery chemistries., charging NiMH is different to charging Li-Ion and is not interchangeable. You can get chargers that do both because they detect the battery and adjust the charging criteria automatically, but they’re effectively two different chargers in one housing.
Thank you! It looks like those 2 lithium (ion) batteries will need chargers of their own. I kinda hate the idea of having to buy special batteries just for a new type of light, and then have to buy a special charger to be used only for that one or 2 batteries, especially if the lights and batteries I have are doing everything I need. I guess I was just looking for an excuse to buy a new “toy” that puts out 1,000+ lumens.
There are lots of good (and affordable) chargers out there that can charge both NiMH and Li-ion batteries - if you grab one of those, you could use that one as your primary charger from there on out, and not need to worry about which battery needs to go in which charger. The XTAR VC4 and the Liitokala Lii-500 are the ones I keep around, but others will surely have their own recommendations too.
Not to change the subject too much, but would a charger that’s made for 18650 batteries also charge NiMH batteries such as AA and AAA?
I’ll look into those charger models you mentioned.
1. Unprotected 14500s have the same size, protected 14500s are a bit longer because of the protection circuit.
2. No.
3. Most flashlights that support 14500s will also support AAs using a boost driver (probably won’t sell well to the general public otherwise), but not all of them. Not all flashlight that support AAs will support 14500.
An considerable issue with flashlights that support both 14500s and AAs is that many of them don’t have LVP (low voltage protection, i.e. the flashlight should refuse to work at all between 1.9V and 2.5V to protect the cell yet being compatible with AAs ). If the flashlight doesn’t have LVP, it will easily over-discharge an unprotected 14500 cell to about 0.8V if kept turned on unattended. It’s dangerous to recharge a over-discharged cell so you should discard it. If the flashlight doesn’t have LVP it’s better to buy a protected 14500 to prevent over-discharge if the light supports the extra length and the current isn’t too much.
4. I don’t know. The voltage of a fully charged 145000 is a bit higher than 2xlithium AA, it isn’t assured that all drivers will support it. If it goes into direct drive it may be too much current for the led or the driver. Since even the highest capacity 14500 (the 1000mAh Vapcell 14500 ) contains less energy than 2 eneloops you will notice for sure a reduction in runtime even at the same brightness.
5. There are multi-chemistry chargers. Even a $6 Zanflare/Littokala Lii-100 can charge 14500/18650/NiMh AA. If you want to charge several cells at once the price increases a bit. If the charger allows to select the charging current, for 14500s is better to keep it low, at 500mA or less to reduce the stress on the cells.
The little Li-100 is a single cell charger that will charge just about anything from NiCads, NiMh, Li-Ion. It also has a USB output on it so the cell in the charger can be used to charge say a cellphone or something similar. Easily fits in a pocket and are dirt cheap and reliable.
The Ultrafire C3 is an example of a light that can usually use either 14500 or AA. It will say so in the description. Most small boost drivers for this purpose are designed for AA and survive the 14500 because above a certain voltage the driver goes into direct drive (no control other than the sense resistor and led Vf limiting current. Because of this it’s a good idea to use protected cells to avoid smoking the driver with a low internal resistance “hot” cell. Some are one mode and some are multi mode drivers. The common size for a AA/14500 driver is 15 mm diameter.
If you’re going to buy a AA light and want to use AA cells do yourself a favor and stay away from alkaline cells. They don’t perform nearly as well in such a high drain usage and are rediculously prone to leaking and ruining the light. They’re more expensive but eveready ultimate lithium’s are worth the extra and don’t leak. This form factor is a really nice choice for both edc and back up.
I’ve seen what you mean about the alkalines. For that reason, I check the batteries in all devices once a month in order to catch leaks early before they cause any real damage. For high drain flashlights and my digital camera, I only use NiMH batteries.
Ok, one more question:
I have an old charger that can charge up to 4AA batteries. It was made for Ni-Cads. Can I use this with the current Ni-MH batteries? Or should I just throw it away? I’d hate to do that, but if it’s not safe to use anymore……
I just did a google search and found that they can be used, but a full charge could take a long time and may overcharge if not stopped in time. I suppose the Ni-cad charger could be used (carefully) to partially charge a NiMH battery in a situation where that’s all that was available as a charger. Well, here’s a link to the source: http://www.greenbatteries.com/nimh-battery-charger-faq/#NiCD%20charger%20for%20NiMH%20batteries
