are aaa/aa recharga...
 

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[Closed] are aaa/aa rechargables as bright in an led torch as a regular duracell?

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hopefully not a thick question, but i need some new aaa for my running headtorch and wondered if rechargeable jobbies, if i bought some decent ones not cheapo off ebay, will give the same brightness?

for some reason i seem to recall reading that they might not, but who knows i am no battery expert.


 
Posted : 09/10/2017 10:08 am
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rechargeable cells are I think 1.2v compared with 1.5v for standard metal cells (AAs and AAAs).

But IIRC LED's light output is a function of forward current not voltage (as long as voltage is within parameters) so you should get much the same light output for either type of cell. Im pretty certain I do with my alpkit head torches and mainly use rechargeable.


 
Posted : 09/10/2017 10:11 am
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depends. rechargeables are lower voltage than regular batteries so if you are only just reaching the right voltage with ordinary batteries you wilkl be under it with rechargeables. However in practice I find no issues

LEDs need ( IIRC) 3.7 volts so 3x ordinary batteries = 4.5 volts so fine. 3x rechargeables = 3.6 volts. Depends on the circuitry for powering the led


 
Posted : 09/10/2017 10:12 am
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I find that rechargeable don't hold the charge for as long as standard batteries. And with all the online places you can get batteries for very little money, I just bulk buy normal ones. The D cell ones in my Maglite (with LED bulb conversion) have lasted years. If I had used rechargeable they would 100% have needed recharging by now.

No idea about relative brightness though.


 
Posted : 09/10/2017 10:12 am
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It will depend on the headtorch. If it is a cheapo with no flashing modes etc then yes the alkaline is likely to be brighter. However as Stoner says, the LED output is dependant on current really and if there is a proper control circuit then there shouldn't be much difference. On a high power lamp you might actually do better with rechargeables as they usually have lower internal resistance so can produce the current 'spikes' easier

So,
as always
'it depends' 🙂


 
Posted : 09/10/2017 10:18 am
 MSP
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one of these little alpkit muon, 1 x aaa.

https://www.alpkit.com/products/muon

does anyone have any links to online sites for batteries, regular and rechargeable please?


 
Posted : 09/10/2017 10:22 am
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thats a great little torch and is what I use the most. BTW its AA NOT AAA!

I buy batteries from 7dayshop. Their green "good to go" ones are a little like eneloop and are perfectly good.


 
Posted : 09/10/2017 10:24 am
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does anyone have any links to online sites for batteries, regular and rechargeable please?

Eneloops. Check Amazon. Other places may be cheaper (and potentially counterfeit).


 
Posted : 09/10/2017 10:28 am
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Cheers stoner, that will teach me to post before actually looking, I was thinking as well of an old rear light I found in a box so had aaa on my mind.

I agree though cracking little head torch for the cash. I use mine all the time, with the blipper on the back, road running in winter.

Mind you I've just bought a hope r2 and yes heavier and yes wouldn't want to wear it for every night run but for off road at night it is stunning.


 
Posted : 09/10/2017 10:49 am
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I can't believe no one has mentioned waste, land fill, toxic chemicals et c.

You're all prepared to put all those poisons into the environment for a slight improvement in head-torch performance.

Really?

APF


 
Posted : 09/10/2017 10:59 am
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does anyone have any links to online sites for batteries, regular and rechargeable please?

https://www.vapextech.co.uk/

Their low discharge cells are comparable to eneloops, but slightly less money.

I have their AA & AAA cells in a few different LED torches / lights, no complaints.

Wherever you go, avoid Ebay - it's awash with fakes.


 
Posted : 09/10/2017 11:00 am
 DrJ
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Ican't believe no one has mentioned waste, land fill, toxic chemicals et c

Apparently any shop selling above a certain volume of batteries needs to have a recycling point. That effectively includes all supermarkets. Finding said recycling point is another matter 🙁


 
Posted : 09/10/2017 11:28 am
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cheers, vapetech seems decent pricewise.

but now that alexpalacefan has spanked our little enviromental arses i shall be working up a crowdfunder scam. anyone want to invest in a wooden frame bike with natural rubber tyres and hemp tape drivetrain? you get a free organic t shirt and its only £500 investment a pop!!!


 
Posted : 09/10/2017 12:20 pm
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I had the Vapextech AAA's. They were crap... didn't hold their charge at all. I've used loads of different Eneloop/LSD type batteries over the years and have now standardised on the Panasonic Eneloops bought from a reputable vendor , usually direct from Amazon. The 7Dayshop ones mentioned above are good for a cheap alternative - mine have been going for years and performance is close to the Panasonics.


 
Posted : 09/10/2017 12:31 pm
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alexpalacefan - Member

I can't believe no one has mentioned waste, land fill, toxic chemicals et c.

You're all prepared to put all those poisons into the environment for a slight improvement in head-torch performance.

Really?

APF

With regards to what?
Batteries in general?
Not sure what you're getting at?

Much better to buy a device with batteries that can be charged & replaced when they are at the end of their charging life, than buying something with a built in battery where the whole lot will need to be thrown away.

My new rear light uses AAA's; as did the light it replaced.
I have bought Duracell rechargeable batteries that supposedly only lose 20% charge over a year, so I can leave them on the bike & be confident that they will still have charge.
Run time of the light beats most lights with built-in batteries because the AAA batteries have much more capacity & when they do need charging it takes a few hours with a mains charger that I have in the house (which I have owned for over a decade - the charger, not the house).
I did the same with my previous light; a Lunar R2, which was several years old and only needed a replacement because it bounced free of the saddle bag mount I was using, on a particularly bumpy road and I lost it.

Lots of places have battery recycling collection now, so there is no excuse for people to just stick them in the bin.
I have an old plastic box in the garage that I use to store dead batteries & bulbs in. When going to the tip, I just take it with me & put them in the correct recycling bins.


 
Posted : 09/10/2017 1:14 pm
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rechargeable cells are I think 1.2v compared with 1.5v for standard metal cells (AAs and AAAs).

Nominal voltage, with no load.

Alkaline cells have much higher internal resistance so the supply voltage drops the more current you take. With a decent load (like say lighting) you might find greater voltage across the LED with rechargables than with alkalines even though the nominal voltage is less.


 
Posted : 09/10/2017 1:36 pm
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I had the Vapextech AAA's. They were crap... didn't hold their charge at all.

Standard or the low discharge? Genuine or from an Ebay seller?

Vapextech low discharge have been reviewed independently and stack up well.


 
Posted : 09/10/2017 1:47 pm
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The nominal voltage doesn't mean the same thing for alkaline and rechargeable though. For alkaline it's the voltage when fully charged, for rechargeables it's the mid discharge voltage. In reality the range of voltage is fairly similar for both, though the discharge curves are different, so there's little difference in voltage for a part discharged cell. Alkaline will maintain voltage for longer at the start of discharge, so after 10% of runtime the alkaline powered torch will be brighter, though in contrast rechargeables maintain voltage better near the end of discharge, so you'll get usable light for longer. All assuming unregulated lights and ignoring the issue molgrips mentions which swings the advantage to rechargeables.


 
Posted : 09/10/2017 1:48 pm
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Oh and I've found vapextech good in both aa and aaa, they're what I always buy


 
Posted : 09/10/2017 1:49 pm
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I have several small LED flashlights that will take AA cells, but I’ve been using 14700 Li-ion rechargeable cells for ages in them, with no issues at all, although they’re single cell, not double, not sure if that would make a significant difference.

alexpalacefan - Member
I can't believe no one has mentioned waste, land fill, toxic chemicals et c.

You're all prepared to put all those poisons into the environment for a slight improvement in head-torch performance.

Really?

APF


You [i]have[/i] heard of recycling, I take it? 🙄


 
Posted : 09/10/2017 5:01 pm
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Very often less bright initially but alkalis droop fast as they discharge so even though they start off at 1.5v that gap narrows. And AAAs even more so.

It doesn't work so well for AAA applications but a 14500 IMR cell is a direct fit replacement for an AA. Now it produces 3.7/4.2V so if you replace 2 or 3 AAs with 2 or 3 IMRs you're probably going to blow something up but 1 IMR and 1 dummy cell can work really well.

(sometimes you can replace 1 AAA with a 18650)


 
Posted : 09/10/2017 5:43 pm