Best head torch on AA battery?

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Omega
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Joined: Sat Feb 11, 2023 8:45 pm

Best head torch on AA battery?

Post by Omega »

I have lots of 80% full AA batteries - I have thermostats in every room that allow me controlling the temperature efficiently and save money, so batteries are not lost entirely. I wonder what is the best head torch on AA batteries I could get myself where I could finish these batteries? I want something compact because I am likely to store it either into my bike (bikes are not reliable and they often break during the night, I need a head torch to replace fuses or bulb or something else in the night) or in my hunting bag (I stalk deer, so I often have to gralloch when it is dark)
I would like having something quite powerful, maybe even something what I could use instead of lights on a bike (I once was in a situation when I was less than 2 miles from home and my lights have gone completely, I spent 2 hours to do the last bit of trip that might take me only a few minutes if I had a powerful torch to show myself properly in the dark), but smaller size is more important. So, 400 lumens will be great, above 200 lumens is ok, but it should give me lower lights too as 200 lumens can blind me if I need to work on the bike - I will accept I have to wait for 2 hours to do the last 2 miles if the price is right and the head torch is small enough
Thanks
Yorkshire Andy
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Joined: Thu Oct 03, 2013 4:06 pm

Re: Best head torch on AA battery?

Post by Yorkshire Andy »

Look at the olight ir5 totally against your original brief but bear with ;)


https://www.olightstore.uk/i5t-elite-da ... efa4287307


(Note the link says affiliate it's what popped up in Google nothing to do with me I get nothing )

Not a head torch but the double way clip will let you attach it to a baseball cap peak or a helmet strap / hood or clipped to the back of a pair of riding gloves . easier to carry and a DIY ranger band made of old inner tube will make a quick ghetto mount for handle bar use



Dedicated head torches

Quick Google throws these up:


Thrunite TH20
https://homeloft.uk/products/thrunite-t ... cycling-cw


Fenix HM23
https://www.fenixlight.co.uk/product/fe ... dlamp-1785

Lifesystems Intensity
https://www.amazon.co.uk/Life-Systems-I ... th=1&psc=1

Few YouTube reviews of them flashing up you pays your money and all that ;)

Problem with power is at 200lm you'll flatten a single AA in next to no time
If your roughing it, Your doing it wrong ;)

Lack of planning on your part doesn't make it an emergency on mine
Frnc
Posts: 3205
Joined: Sat Mar 12, 2022 1:54 pm

Re: Best head torch on AA battery?

Post by Frnc »

I could be wrong, but as far as I am aware, the best quality head torches either use AAAs (3 or 4), or rechargeable units (eg Petzl CORE), or in some you can use either. I have a Black Diamond Storm that uses 4 x AAAs. Mine is 375 lumens, but the later ones are 400, 450 and 500.

Petzl are another good make.

NB, this may have changed, but on mine, the bottom right battery is a bit hard to extract, so I put a piece of ribbon under it to pull it out.
Frnc
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Joined: Sat Mar 12, 2022 1:54 pm

Re: Best head torch on AA battery?

Post by Frnc »

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korolev
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Location: Land of the South Saxons

Re: Best head torch on AA battery?

Post by korolev »

When you say "80%" full, how are you measuring that ? If it's by voltage (1.2v ish) then your batteries are almost done.
I had a load of second hand AAs that my Mrs got from work (recovered kit had to have new batteries fitted before going back out and some of them were nearly new). I measured each one and kept any with more than 1.4v but even they only lasted a short time.
So I started only keeping those with more than 1.5v (ie nearly new) and they were mostly ok.

I've had a rationalisation of my torch collection and am getting shot of proprietary cells and CR123/16350 etc. I am only going to keep lights that take 14500 but can use AA as a backup because they're available everywhere and 18650 lights.

Personally I'd advise getting a 18650 head torch and a decent battery charger (Nitecore i2/i4 will charge pretty much anything).
Omega
Posts: 80
Joined: Sat Feb 11, 2023 8:45 pm

Re: Best head torch on AA battery?

Post by Omega »

korolev wrote: Thu Oct 26, 2023 10:13 am When you say "80%" full, how are you measuring that ? If it's by voltage (1.2v ish) then your batteries are almost done.
I had a load of second hand AAs that my Mrs got from work (recovered kit had to have new batteries fitted before going back out and some of them were nearly new). I measured each one and kept any with more than 1.4v but even they only lasted a short time.
So I started only keeping those with more than 1.5v (ie nearly new) and they were mostly ok.

Personally I'd advise getting a 18650 head torch and a decent battery charger (Nitecore i2/i4 will charge pretty much anything).
I checked my used batteries, they are all 1.4 V. I have 20-30 AA batteries that are this condition plus lots of AA batteries that are new.
I have about 8 torches at home, but most are with built in batteries. And I don’t use torches often, most often use is for hunting. I charge torches prior each hunt, which I find inconvenient. And I rarely check my torch in the bike. That’s why I want to put and forget AA torch along with a few spare batteries
tarmactatt
Posts: 48
Joined: Sun Dec 01, 2013 3:56 pm

Re: Best head torch on AA battery?

Post by tarmactatt »

korolev wrote: Thu Oct 26, 2023 10:13 am When you say "80%" full, how are you measuring that ? If it's by voltage (1.2v ish) then your batteries are almost done.
I had a load of second hand AAs that my Mrs got from work (recovered kit had to have new batteries fitted before going back out and some of them were nearly new). I measured each one and kept any with more than 1.4v but even they only lasted a short time.
So I started only keeping those with more than 1.5v (ie nearly new) and they were mostly ok.

I've had a rationalisation of my torch collection and am getting shot of proprietary cells and CR123/16350 etc. I am only going to keep lights that take 14500 but can use AA as a backup because they're available everywhere and 18650 lights.

Personally I'd advise getting a 18650 head torch and a decent battery charger (Nitecore i2/i4 will charge pretty much anything).
Good advice.

This reply isn't just for you Omega, I'll elaborate to help people searching for this in the future, as it comes up from time to time.

Best way to measure the state of alkaline "Batteries" (technically, cells), is to do so under a load and see what the voltage does- if it sags down to 1v (for example) then the cell is dead and should be recycled. Good battery testers should do this for you.

If you measure open circuit voltage (with a digital multimeter, etc) without applying a load, the cell can read as having voltage despite actually having very little energy remaining. Different cell chemistries have different SOC (State Of Charge) behaviour- Alkaline can 'bounce' back up a bit after a load is removed. NiMh is quite "flat" discharge, around 1.2v for a long time, before suddently dropping off. Lithium Cobalt is reasonably linear (4.2v = full, 3v = empty). LiFePO4 is flattish again.

Wikipedia link to approximate state of charge vs voltage for alkaline cells: https://en.wikipedia.org/wiki/Alkaline_battery

It's important not to mix brands/levels of charge- alkaline cells have a nasty habit of leaking even when new and unused! Taking eg. 2 AA's out of your thermostat, and mixing them with an additional AA from a different thermostat, probably at a slightly different state of charge, is going to increase the likelyhood of a cell leaking and spoiling your light(s).

If you've devices you can run NiMh rechargable, I'd strongly reccomend the Ikea Ladda cells. Eneloop are the gold standard but are quite expensive. The NiMh cells are good as they can supply a lot of current- Alkaline cells are typically "weak" in comparison. I do appreciate not all devices work well on NiMh due to the slightly lower voltage (1.2V)

This website is a little dated, but has an excellent comparison table- compare the Duracell Ultra Power AA (for example), with the IKEA Ladda AA 2450:
https://lygte-info.dk/review/batteries2 ... arator.php

At currents greater than c.200ma, the NiMh maintains voltage much better than the alkaline. 400 lumens of light... Let's assume the efficacy of the torch is 100lm/w. you'll need 4W of power for 400lm. Using 2x AA cells, I'll be generous and say they're brand new and can do 1.5v, you'll need 2.6A of power to get 4W, way more than those alkalines are happy to produce, so their voltage sags - check the box for 2A and 3A on the comparator linked above to see what the voltage does.

If you were looking to "use up" Alkaline cells, your best bet is a Joule Thief type circuit- these are capable of running cells down to completely flat, unfortunately, these don't produce much power to drive an LED.
Moorland Prepper
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Location: On the edge of the Pennines

Re: Best head torch on AA battery?

Post by Moorland Prepper »

I've been looking for a head torch and was surprised to find that some of them are described as having 'motion detection' on them. Presumably this is to switch them on and off? Has anyone got one of these?

I'm always a bit wary of having techie stuff on simple gadget, so does it work OK?
Yorkshire Andy
Posts: 8773
Joined: Thu Oct 03, 2013 4:06 pm

Re: Best head torch on AA battery?

Post by Yorkshire Andy »

Moorland Prepper wrote: Mon Feb 26, 2024 8:03 pm I've been looking for a head torch and was surprised to find that some of them are described as having 'motion detection' on them. Presumably this is to switch them on and off? Has anyone got one of these?

I'm always a bit wary of having techie stuff on simple gadget, so does it work OK?

I've a couple of Screwfix they come in handy off grid use them as mini security / courtosy lights in the awning or similar
If your roughing it, Your doing it wrong ;)

Lack of planning on your part doesn't make it an emergency on mine
Frnc
Posts: 3205
Joined: Sat Mar 12, 2022 1:54 pm

Re: Best head torch on AA battery?

Post by Frnc »

Moorland Prepper wrote: Mon Feb 26, 2024 8:03 pm I've been looking for a head torch and was surprised to find that some of them are described as having 'motion detection' on them. Presumably this is to switch them on and off? Has anyone got one of these?

I'm always a bit wary of having techie stuff on simple gadget, so does it work OK?
I dunno. My Black Diamond has a function where you can tap it, but I prefer to just press the button. It's very simple. One press = on. Long press gradually dims it and the brightens it, you release where you want it. It saves your setting when you turn it off.