Using NiMH batteries vs. Alkalines

I am new to flasholicism and this is my first post here. I've searched the forum, but no definite answer. I purchased a Streamlight Propolymer 4AA Luxeon flashlight and was wondering if I can use high capacity NiMH batteries that I use for my digital camera in it. Or would this adversely affect the flashlight in any way. Streamlight says to use alkalines.

Thank you,

Pradeep

If anything NiMH will last longer in that application as far as run time goes. Alkalines do very poorly under any kind of load exceeding a few hundred mA. The only time you might want to use alkalines is if you plan to use this as a standby light, meaning that you want it ready for emergencies if it's been sitting for six months or a year. If so, the self-discharge of NiMH would make them unsatisfactory. As a very general rule of thumb, if you find yourself buying a new set of batteries every three months or less then consider using rechargeables. NiMH usually retain a good portion of their capacity over that time period. The shorter the time between battery changes, the more you save by using rechargeables.

If you're very good at remembering to charge all your batteries at least every few months, as I am, then you can put rechargeables in everything without worrying about self-discharge. I've had alkalines leak in a bad way more often than I care for. I've basically stopped using them except for clocks for that reason. It's less inconvenient to remember to charge ~150 cells every few months than it is to clean out battery acid from a leaking alkaline.

Thanks for the quick reply. I am an avid camera nut and have about 60 high capacity NiMH AA batteries lying around to power my cameras, flash heads, etc. I keep them topped off reguarly with a good Lenmar rapid charger with conditioning and would love to use them in my flashlight. Just the dire warnings of using anything other than alkalines got me worried.

Hi jtr,
How much do you think the max brightness would be reduced since the voltage rating of NiMH is 1.2V as compared to Alkalines at 1.5V...or would the LE make up for this??
Thanks..

check the charts in the battery forum, where they compare the discharge curves of alkaline and ni-mhy. they are Stickey threads, called "shootouts"

basically with a fair load on both of them, they both are at 1.2 during discharge.
Voltage is not everything, how well it STAYS at that voltage when running is everything when it counts.

ni-mhy can replace alkalines easily in just about everything, the things it cannot would be driven to hard with the ni-mhys. so usually there is less suffering of the ni-mhy being at 1.2v than the alkaline getting even worse than that.

adding, with current regulated light stuff, if the current is being regulated very tight, you should observe little to no differences in output using either.

I run NiMH's in my Propoly Lux 4AA's and they work fine. I haven't done a back-to-back comparison, but I can't tell a brightness difference between Alkaline's and NiMH's, which is undoubtedly helped by the regulation. I haven't used them enough in a day or weekend to need recharging, and I always top them off before I take them out, so I can't comment about runtime with 2500 mAH AA's.

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pradeep1 said:
Thanks for the quick reply. I am an avid camera nut and have about 60 high capacity NiMH AA batteries lying around to power my cameras, flash heads, etc. I keep them topped off reguarly with a good Lenmar rapid charger with conditioning and would love to use them in my flashlight. Just the dire warnings of using anything other than alkalines got me worried.

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pradeep1,

You can also use those AA NiMhs in C and D cell lights, if you simply fashion a "holder" tube for them. I use a section of PVC pipe. Also, Walmart and online vendors sell small plastic cylindrical "adapters" that will fit over the AAs, in both C and D size.

Good luck and have fun!

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AFAustin said:
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pradeep1 said:
Thanks for the quick reply. I am an avid camera nut and have about 60 high capacity NiMH AA batteries lying around to power my cameras, flash heads, etc. I keep them topped off reguarly with a good Lenmar rapid charger with conditioning and would love to use them in my flashlight. Just the dire warnings of using anything other than alkalines got me worried.

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pradeep1,

You can also use those AA NiMhs in C and D cell lights, if you simply fashion a "holder" tube for them. I use a section of PVC pipe. Also, Walmart and online vendors sell small plastic cylindrical "adapters" that will fit over the AAs, in both C and D size.

Good luck and have fun!

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I'll have to check this out. I was wondering about that, since I want to do the Luxeon mod to my 3 D cell Maglite and didn't want to invest in more NiMH batteries and a new rapid charger. Very cool.

Good news. I was wondering about this also. Ive started using NiMH rechargeables in my Streamlight Jr. Luxeon based on what I read on this forum and it seems fine. After reading this thread and from what I know about their use in other things it seems that NiMH rechargeables will also be fine in my AA and AAA minimags that I have added TerraLux LEDs to. Is that correct? What about unmodified (incandescent minimags)? Thanks.

Thanks VidPro, your definitely right!
I had forgetton how bad Alkalines perform under load...and Pradeep1 is only using AAs at that.
I have read some of the bat shootout thread in the past, but mainly for brand comparison. Doing a quick check, I couldn't find the exact comparison graph between NiMH and Alkalines but I did see the graph on Alkaline AA with a 1 A load dropping Real Fast to 1.2 V! /ubbthreads/images/graemlins/smile.gif

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Luxman said:
Thanks VidPro, your definitely right!
I had forgetton how bad Alkalines perform under load...and Pradeep1 is only using AAs at that.
I have read some of the bat shootout thread in the past, but mainly for brand comparison. Doing a quick check, I couldn't find the exact comparison graph between NiMH and Alkalines but I did see the graph on Alkaline AA with a 1 A load dropping Real Fast to 1.2 V! /ubbthreads/images/graemlins/smile.gif

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I was using Alkaline AAs. /ubbthreads/images/graemlins/blush.gif

Hi, Gadget Travel.

Yes, you certainly can use Nimh batteries for your Terralux TLE5 or probably other Terralux drop-ins.

You might observe a difference for brightness initially(since Alkaline starting volt as ~1.5v and Nimh ~1.2v), but it might not be much difference towards the end. For incan as well, you could use Nimh batteries, but it would not be very satisfying since it looks kinda dim. /ubbthreads/images/graemlins/wink.gif

I want to mention that in most LED lights, NimH is a good thing!

When it comes to incandescent lights, an extra NimH cell driving a bulb meant for the light (ie: 4 NimH against a 3 cell bulb) is usually better.

The really great things NimH do are to give a somewhat regulated run instead of getting dimmer all the time.

At my usage pattern, my Minim*g with LUXIII module gets fresh charged batteries maybe every two weeks or so. (Think I'll do it right now!)

Actually nimh fresh off the charger is about 1.4v and after a few days over 1.33v so unless they have been sitting a few weeks they start higher than 1.2v.