1.5v 14500 lithium ion cells?

My technical knowledge is very limited so please allow an elementary question: What are the advantages of a 1.5 volt (not 3.6 - 3.7v) 14500 lithium ion cell, such as the Fenix ARB-L14U: https://www.batteryjunction.com/fenix-arb-l14-1600u.html as opposed to a NiMH cell like an eneloop?



first things that I’d recall are higher & better continuous amp ratings, less weight, more robust than standard alkaline cells, higher capacity
In this specific case a customer would also not have to buy a charger and carry that one with another cable. useful for vacation (if we at some point go on a vacation anyway).

They keep 1.5V over the entire discharge. Not very useful for flashlights, but they are useful for badly designed devices that don’t support the lower voltage from NiMH cells. Some models with higher capacity have more total energy than Eneloops Pro’s, the one you linked has the same energy as a normal Eneloop.

Besides their price their disadvantages are their low discharge limit (they actually have a protection circuit rather than just voltage sag) and the electromagnetic noise they make, which may interfere if next or inside a radio.

High and stable voltage throughout discharge. Energy density isn’t top of class, but for devices sensitive to the lower voltage of NiMH vs Li-primary and even fresh alkalines (at very low current), then they can be a nice option. In a past life, I know my partners remote flash (photography) didn’t like NiMH and always warned of low batteries even when fully charged.

In summary, it fills a niche. If you already have eneloops and they work in your device, I’d stay with them.

Thanks, gentlemen. Very helpful.


if it`s a device that takes 2xAA then if you buy a dummy AA, pop it open and cut the wire that connects both ends and put a diode in place of it (a 1n4001 will do for many things), it will drop the voltage by .7 of a volt, so when used with a regular protected 14500 batt you get really close to 3v and don`t risk causing damage, it`s great for some wall clocks for instance, or 2xAA mini mags.

Thanks, K.A.

What people have said; stable voltage at ~1.5v until > nothing. They do not drop in voltage, simply quit. You cannot estimate remaining capacity from voltage at all.
The high voltage can be useful for some devices.
The amp output is satisfactory but not high. Then tend to top out at 1.5A and fail at 2A as a result of heating of the voltage conversion mechanism.
Actual milliAmphour capacity is somewhat below a good NiMh. Some of the space in the cell is taken up with charging, voltage coversion, and voltage protection circuitry. Since they are inherently higher voltage the capacity is often given as watt hours.
They often are not good for photography strobes, if the strobe has a high demand for re-charging. So, depends on the application there.
Some of them require a proprietary charger, some via simple mini-USB.

Thanks. I’m taking from all the posts that for for normal 1xAA LED flashlights, I’m better off, as Jared said, sticking with my eneloop and LADDA cells.

I’ve never heard of these before

They’ve been around for a couple years. I have a dozen of the Tenavolt. Had them for about a year now, pretty much constant use, and still seem fine.
I knew what I was getting when I bought them. So far been satisfied. They are WAY better than the NiZn batteries that were around about 10 years ago.
There are a number of brands. Unless you can get them on a good sale, which I have not seen in a long time, they are way too expensive.

How to storage these type of batteries?

NiMH needs no special storage considerations, Li-Ion you should take the voltage down to about 3.6 volts (or only charge up to 3.6v) and keep them in a plastic battery case (they only cost pennies) somewhere cool.
NiCd drain them entirely and then short contacts out for storage.

that`s about it really :slight_smile:

You are wrong, it’s 1.5v max!

Who`s wrong? and what`s 1.5v max? (context is everything).

New to me too. The voltage is determined by the chemistry of the battery. That’s why you get 1.2V out of NiMH or NiCad batteries, 1.5V out of alkaline batteries, and 3.7V out of lithium ion batteries. The way this battery gets 1.5V is to incorporate a small buck converter to reduce the voltage from 3.7V to 1.5V. That’s also why the voltage is stable until it reaches the point where the lithium ion battery inside no longer delivers enough voltage to power the buck converter and it stops working until recharged. Seems like a rather expensive way to power a clock though. Even a cheap alkaline battery bought three or four for a dollar at my local dollar store will power my clocks for 6 months between battery changes.

BTW if you use a single 3.7V lithium battery to replace a pair of 1.5V batteries for 3V be sure to use the correct size resistor, not diode to drop the voltage to 3V. In many cases a single 18650 battery works fine to power a device using three 1.5V batteries. I did that with a bunch of lighted Halloween pumpkins recently.

a resistor will still deliver an over voltage below a certain current drain and is dependant of the load remaining constant to work (this is Bad design), you need a Si Diode to get a clean 0.7v drop. :wink:

the only time you should use a resistor for this sort of thing is if you put a 3v Zenner across it for shunt regulation.

The 1.5v Li-on get that way by going through a voltage conversion. There is +no way +to determine capacity from these with voltage. That’s one of their shortcomings.
You either:

  1. GUESS - which is what I do. I run the battery for ‘awhile’ in it’s usual device and simply take it out when I think it’s ‘low enough’. I’m happy with anything from 20-50%. Storage is not ‘rocket science’.
  2. Test capacity with an appropriate charger/device. Then……
  • Charge completely.
  • Discharge to level capacity you desire while monitoring. (Again, voltage will NOT work.)

3. Reverse of # 2. Discharge to low voltage cut off. Charge while monitoring to desired level. This would be challenging since you need the proprietary charger of would have to rig up a USB driven system.
You could GUESS, based on charge time from low voltage cut off, if you determined that time from a single cell charge.

It is possible with kentli!

News to me. Can’t do that with the Tenavolt.