rechargeable or primary for AAA lights?

Batteries and Chargers Rechargeable Batteries
1

I'm studying the Battery Comparator graphs for AA/AAA batteries http://lygte-info.dk/review/batteries2012/CommonAAcomparator.php

For common primary AAA versus Eneloop AAA (normal or lite) batteries,

at 0.1A current drain, the primary AAA (alkaline) might have a slightly higher capacity (mAh) than the Eneloop AAA.

but at 0.2A current drain, the alkaline AAA and Eneloop AAA will have nearly similar capacity, although the Eneloop would have a higher voltage for most part of the usable capacity.

at 0.5A current drain, the primary AAA will basically have half or less the capacity of an Eneloop AAA.

(Reason for this is I only have a handful of Eneloops, while we have many alkalines at home, so I'd like to know which lights would work OK with alkalines [ie. the light's current consumption is less than 0.2A]; also the lights may not be used that often, so using the cheaper alkalines would still be ok.)

So, what this means is that in most cases, an Eneloop AAA (or other comparable LSD NiMh) will be better choice.

I decide to check the current drain of some lights we have at home (using an uncalibrated Mastech MS8229 multi-meter to check tail current)

1) Energizer 3xAAA (4.5v) flashlight, using new alkaline AAA or Eneloop AAA, I measure the current at just around 0.11A (does this mean 0.11 divide by 3pcs AAA = .037A current drain for each AAA). In this case, since it has a very low current drain, an (3pcs) alkaline AAA would probably have longer runtime than the Eneloop AAA. <== Is this assumption correct?

2) COB LED flashlight: I purchased these lights (also uses 3xAAA) in 2 occasions from this AliExpress seller:

https://www.aliexpress.com/store/product/LED-Flashlight-COB-Led-Portable-Plastic-Perfect-Torch-Lamp-With-Magnetic-And-Clip-For-Camping-Outdoor/1946571_32659672698.html

a) The earlier batch, I measured a current of around 0.36A (using freshly charged Eneloop AAA) for the COB LED light, and around 0.22A for the front light. (if I just subjectively [sorry, I don't have a good brightness-measuring equipment] compare the front light, it seems the 0.22A front light is about as bright as the 0.11A light of the Energizer 3xAAA flashlight)

b) However, for the 2nd batch, I measured a current of around 0.82A (freshly charged Eneloop AAA) for the COB LED light, and around 0.44A for the front light. (comparing the 0.44A front light to the Energizer 3xAAA flashlight, this is noticeably brighter, but not twice as bright -- considering it's using 4 times as much current).

For the 0.36A COB LED light (divide by 3xAAA), that means just 0.12A per AAA battery, so if using alkaline AAA should still yield good capacity. (and current drops as voltage drops)

For the 2nd batch 0.82A COB LED light (divide by 3xAAA), that gives 0.27A per AAA battery, now this is double the 1st batch (the 2nd batch' light output appears somewhat brighter, but not too significant), using Alkaline will probably not be that good anymore.

Is the above analysis correct?

3) COB LED headlamp (also uses 3xAAA):

https://www.aliexpress.com/item/Waterproof-COB-LED-Flashlight-Headlight-3-Modes-Headlamp-Outdoor-Head-Light-Lamp-Fishing-Camping-Hiking-Cycling/32721684541.html

- using the freshly charged Eneloop AAA (well, it's not that freshly charged anymore since I used it to test above, so voltage could have dropped very slightly), measure 0.46A on 'high' setting, and 0.11A on 'low' setting.

so on 'high' setting, 0.46A divide by 3 = around 0.15A per battery. Using alkaline is still OK compared to using Eneloops.

on 'low' setting, 0.11A divide by 3 = around 0.037A per battery, then alkaline will likely have longer runtime

4) 3+1modes LED headlamp (also uses 3xAAA):

https://www.aliexpress.com/item/Mini-Head-Lamp-4-Mode-Waterproof-600Lm-R3-2-LED-Flashlight-Super-Bright-Headlight-Headlamp-Torch/32800642010.html

  • using (somewhat) freshly charged Eneloop AAA, the white light on 'high' gives around 0.35A current (divide by 3 = .12A per battery), so using alkalines would still be good.
  • white light on 'low' setting uses around 0.10A; red light uses around 0.07A, so alkaline might have longer capacity.

5) 'generic' 3xAAA flashlight (similar size to the Energizer 3xAAA flashlight above):

  • this is an older flashlight lying around at home, I measured its current to be around 0.30A, so that means around 0.10A per battery. Using alkalines would still be OK. This generic light seems to be almost as bright or only slightly brighter than the Energizer 3xAAA flashlight (which uses just 0.10A or 0.033A per battery). Seems like the Energizer 3xAAA flashlight is really designed much better..

~~~~

in conclusion, only the COB LED flashlight that uses 0.82A would not fare well with alkalines, but the rest should still be OK. Also special mention to the Energizer 3xAAA which seems to use a comparatively low current (just around 0.10A) and outputting an adequate amount of light for close-up indoor needs [this flashlight is rated by manufacturer to have 'up to 45 lumens', which I'm unable to verify though])

2

My main reason for putting NiMH batteries in AAA lights is that they don’t leak. Nowadays they hold their charge for long periods so lifespan isn’t an issue. Also rechargeable batteries can be topped up, use a primary and you don’t want to throw it out after the first couple of uses, so you are never really sure how much life it has left, especially if you have numerous lights.

Keep the alkalines as backup, a nice way to store them is inside clear AAA - AA adaptors, that way they are not only backup for AA devices as well, but if they leak the leak is both visible and contained in a non-corrosive enclosure.

3

Your basic premise of dividing the amp draw by 3 is incorrect.

When you run batteries in series, the voltage is cumulative and the same amperage flows through all cells.
Imagine literally laying the 3 batteries head-to-tail and visualizing it.

So your 3xAAA lights are 3 AAA batteries in series (1.5+1.5+1.5) ~4.5V , and the current you are measuring is what is seen by every cell equally.

You are already familiar with HJK’s comparator, so you you can see that alkaline AAA will have very significant voltage sag at 0.2A or more. Eneloop Pro AAA will perform much better, for both output and runtime.

But even using top-tier batteries like Eneloop Pro, 3xAAA is an awful battery format. Depending on how long the battery carriers are, an 18650 Li-Ion can fit in many 3xAAA lights, and is vastly superior in all ways.

4

Thanks for correcting me.
(Actually I wasn’t sure if that’s the right way to do it, so I posted the above, hoping that someone will correct me if I’m wrong, and it turns out my assumption was indeed wrong…)

That’s true, but 18650 batteries are still very hard to get here in our country — they are very expensive too (eg. about 2-3 times the price I’m seeing compared to AliExpress or Banggood) if I check their prices in vape shops. I think 18650 flashlights are still very uncommon here in our country (I’ve never seen such lghts in the Ace Hardware or other local “handyman” stores here. Hoping that may change soon, and hopefully 18650 batteries will become more common locally.) Thus far, my18650 flashlights I bought are all from online only. Generic 18650 flashlight (fake “XML T6”) from a local online store. So far my “branded” 18650 flashlights are only the Astrolux (from Banggood) and Convoy (from AliExpress).

AAA and AA format flashlights seem to still be the common ones here. I myself am trying to move towards 18650 (after reading the BLF forum, which led me to purchase the BLF A6/Astrolux S1 and Convoy S2+/C8, which I now have. Unfortunately, I only have one Samsung INR18650-30Q that I switch among those flashlights, as I don’t have another high-drain battery. I have a few pieces protected NCR18650B that have arrived which I use for those flashlights. My previous order of INR18650-30Q (Banggood) got cancelled so I ordered from an AliExpress seller and it’s on the way already. But also unfortunately, that may be the last I order for awhile, since that AliExpress store now says “does not ship to the Philippines” anymore…)

Just curious, are 18650 flashlights already quite common in the developed countries? (I’m in a 3rd-world developing country…)

5

That is unfortunate that it is so difficult to get 18650 Li-Ion batteries in your country. :frowning:

18650 flashlights and batteries can be “very” common depending on what demographic you are looking at.

Flashlight enthusiasts - obviously yes, and Li-Ion are easy to get for reasonable prices mostly, but only through mail order - brick&mortar stores like Lowes/Home Depot/Ace Hardware do not carry them. Typical mail order places like Amazon sell 18650 flashlights, but typically sell 18650 batteries from “name brands” like Nitecore or Olight, which are overpriced re-wraps of OEM Samsung/LG/other cells so enthusiasts don’t use them very often. To get decent prices on specific cells, one must either use Chinese websites (Banggood, Gearbest, Aliexpress) or one of the few local retailers (LiIonwholesale, IMRbatteries, in the US, I think Nkon in the EU?).

“Casuals” who are aware that good lights exist, (but aren’t interested in making flashlights a “hobby” like us) can easily source an 18650 light and “branded” re-wrap battery easily on Amazon, although they will pay more for them. Fun fact: read Amazon reviews of an 18650 light and see how many people gave it 1-star because it didn’t come with batteries (like their previous AA/AAA lights did) and they can’t get a battery at the local grocery store. Basically they are giving a product a bad rating because they are uninformed, usually because they didn’t bother to read the sales listing where it says, “Battery: 1x18650 Li-Ion” right there. :person_facepalming:

“Unenlightend” folks who don’t know anything other than the fact that mag-lights are a flashlight name brand they recognize, they can buy any number of generic plastic LED lights at Wal-Mart, Home Depot, etc. The lights these folks buy (because it is what the store stocks) are almost always AA or AAA based.

6

i would be surprised if you cannot find laptop packs to tear down for 18650 cells.
the common cheap lights mentioned here run fine on laptop salvage.that is if they can fit.
obviously the larry light knock offs wont accept them but there are some that take them natively.
some that take a carrier will.
at least most can use an 18500.
do you have walmarts over there?
they clearance out the 18650 and 18500 for the solar lights cheap.
and they are fine for the cheap lights.