# Run times on Magic Shine



## Mikhs (May 18, 2006)

I picked up one of these lights and have used it for four night rides so far. I like the brightness but I am disappointed in the run times that I am getting. I noticed that the indicator light was
coming on short of the two hour mark. The first couple of rides this was near the end of the ride but last night it came on at about the same time and the light completely shut down at 2:15. It didn't seem to dim or go to low power prior to shut down. Luckily I do run a light on my helmet as well so all was good for the ride but I was wondering if anyone else seems to be getting shorter run times than advertised.
I have contacted the dealer I bought it from and am waiting for a response.


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## jaewannabe (Jun 4, 2009)

I just got 2 sets of the magic shines, used on one night ride. It was a 3 hour ride with a full moon so not a real good test of run time as was turning them on and off to enjoy riding by moonlight. I did a timed test before going out, at 4 hours of being on the highest setting my indicator light went to red. I then ran out of time for the test and put it on the charger.


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## lidarman (Jan 12, 2004)

Sounds like the battery is not up to par. I have gotten three hours on high on all my lights.

LED lights with Li-Ion typically don't dim before they turn off. The regulation circuit keeps the current constant until the battery discharges to the lower voltage limit then it shuts abruptly off.

In the case of the Magicshine, the last ten minutes of charge (on high) should cause the button to change from "green" to "red." 

Curious to the ambient temperature of your rides? Battery performance decreases in cold temperatures.


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## Mikhs (May 18, 2006)

lidarman said:


> Sounds like the battery is not up to par. I have gotten three hours on high on all my lights.
> 
> LED lights with Li-Ion typically don't dim before they turn off. The regulation circuit keeps the current constant until the battery discharges to the lower voltage limit then it shuts abruptly off.
> 
> ...


The coldest of the rides was about 8 C or about 45 F. I wouldn't think that would be cold enough to lose 30% of the battery life but I could be wrong. 
Anyone else notice shorter run times in cool temps?


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## WeakMite (May 11, 2004)

I have 2 sets and I've been getting 3:10 to 3:30 on both. I've noticed the decreased runtimes with lower temps (35f)... but only shorter by 10 or 15 minutes. Still haven't had them go off in under 3 hours yet (I've been using them 4 to 6 times per week).

Mine are the old (high/low/flash/off - with 11" cables) got them from Geoman in Sept.

Hopefully the dealer will exchange your battery... that's what I would want in your case.


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## Mikhs (May 18, 2006)

A new battery is on the way.
Thanks for the input guys.


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## znomit (Dec 27, 2007)

Mikhs said:


> A new battery is on the way.
> Thanks for the input guys.


Dont forget to update the poll  
http://forums.mtbr.com/poll.php?do=showresults&pollid=2407


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## lidarman (Jan 12, 2004)

znomit said:


> Dont forget to update the poll
> http://forums.mtbr.com/poll.php?do=showresults&pollid=2407


A poll with feedback loop.

That means I should be able to vote three more times since I have used 4 of these things.


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## goneskiian (Sep 27, 2004)

lidarman said:


> A poll with feedback loop.
> 
> That means I should be able to vote three more times since I have used 4 of these things.


Sorry if this has been addressed elsewhere lidarman but why have you used 4 of these? Did you just buy that many because they're so inexpensive or have you had some issues with the product?

Thanks!


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## lidarman (Jan 12, 2004)

I got one, loved it, got zealous then bought three more. I regained my sanity and realized I didn't need so many so I sold one to a friend who wanted one. 

Now I have one for my wife and two for me.

So far, no problems.

Okay there is a problem. I have two niterider halogen lights and a niterider HID that might never get used again. I feel like a packrat or a collector.


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## bpnic (Aug 14, 2005)

I ran mine the other night for the first time with a mix of high and low beam being used, and my indicator turned red at about 2 hours. I thought it was fully charged. I'll test it again, and if it's a similar result, I'll contact Geoman (great to buy from BTW) and see what he says. Temps were in the low 40's.
Light was fantastic otherwise.....

When I charged it post-ride, the charger turned from red to green in about 2-2.5 hours.


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## goneskiian (Sep 27, 2004)

lidarman said:


> I got one, loved it, got zealous then bought three more. I regained my sanity and realized I didn't need so many so I sold one to a friend who wanted one.
> 
> Now I have one for my wife and two for me.
> 
> ...


You can send those niterider lights to me, I'll make sure they get used!  

Thanks for your impressions.

I've got a dead niterider that I must have left on the charger a bit too long. The replacement battery costs more than a magicshine.  :lol:


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## lidarman (Jan 12, 2004)

goneskiian said:


> I've got a dead niterider that I must have left on the charger a bit too long. The replacement battery costs more than a magicshine.  :lol:


Actually I rebuilt both my niterider aholgen battery packs about 8 years ago (they are vintage 1994 lights with NiCad batteries). It was pretty cheap actually.


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## znomit (Dec 27, 2007)

lidarman said:


> Actually I rebuilt both my niterider aholgen battery packs about 8 years ago (they are vintage 1994 lights with NiCad batteries). It was pretty cheap actually.


:thumbsup: :thumbsup: :thumbsup: 
Get back to us in 2024 on the MS


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## HubbaMan (Feb 3, 2004)

*Weird burn times*

Hi,

I've had my MS now for a few months (received end of September), but due to several issues, none of them bike related, I haven't had the pleasure of taking it out on a ride yet!!

However I do have some strangeness going on with my light.

When I received it from Geoman, I charged up the battery for 4hrs and ran the light. Very impressed with the beam but also noticed the light itself got quite hot, in fact too hot to touch. Because I wasn't actually riding, I never ran the light completely down, so never saw a yellow or red button light.

I decided to run the battery down at one point last week (hoping to go riding soon!) and I never got a button light other then green or no button light at all. The MS ran for as long as I could run it every evening. I didn't want to leave it on overnight for fear of actually killing it completely. In the end the green light wouldn't come on anymore even though the light itself was still working fine, by my estimate I was easily past 12hrs of burn time.

So I read on the forums here a bit and decided to re-charge the battery and run it again. After 4 hrs the green light came on the charger. This morning I plugged the light in at 9am, then turned it on to the brightest setting it has to offer. 
6.5 hrs later the button light is still green and the light is still on, at the same intensity as it was this morning. The light head also runs much cooler, as it did last week when I was trying to get a red light out of the button. It's only slightly warm to the touch, is easy to pick up and handle despite being on for over 6 hrs.

My intension is to run the light until the green light changes to yellow or red to show me the battery is near its end, but I can't help but wonder if the light is no longer running at the same intensity as it should since the run time seems way out of whack compared to other folks here, and it doesn't run as hot as it did before either.

I don't have any way of measuring the light intensity, or to compare it to what it was when I first received the light. If I had to guess, I have a feeling it's not as bright, but again, have no way of proving or disproving this.

I'll follow up with a post this evening to let you know how long the light actually ran for, that is if it has shut off and not still running, but any ideas how/why this might be happening?

Every time I have run the light, it has always been at the brightest setting, so I have not mistakenly been running it at a lower setting.

Thanks


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## gmcttr (Oct 7, 2006)

These lights need moving air to keep them cool.

My guess is that you originally cooked something and now it is running at a greatly reduced output. There simply is no other way to be getting those run times and little heat than to reduce the output.


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## ortelius (Dec 6, 2007)

No way you could run it for 6+ hours on high. Around 3:30 max.

If it lasts so long on high, there is only one explanation: there is something wrong with it and it is probably driven with substantially lower current as it should. It also means you are getting much less light from it as you normally would.


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## conifer0 (Aug 29, 2007)

*So far I'm not disappointed!*

I started out my night rides this year with my 5 yr old NiteRider Enduro Lith HID. Good broad beam, but my friend has a Princeton Switchback 3 that gives a great tight spot with side lighting, much more light output, and incredible battery life (at the cost of carrying a motorcycle-size battery).

My Enduro needed help so I started using my old Planet Bike 10w on the handlebars. This worked OK until I did a group ride. I ran out of water at about 1 1/2 and decided to head back with some other riders that were quiting early. Both my lights died on the way back within a few minutes of each other and I had to rely on the lights of the other riders to make it back. After the ride, I started whining that the both the NiteRider and Planet Bike batteries were so expensive, and a fellow rider suggested I look at Magic Shine.

*Best bang for the lighting dollar period! *

I tried the MS on the bars and my NR on the helmet the first test ride. It was maddening because the MS so dominated the NR that I had to do the rest of the ride with the MS on low! The next ride I switched the MS to the helmet. For me, this is the best combination because when I turn my bars back and forth on technical sections, I don't really notice the NR because the beam is so broad. On the other hand, the MS is great on the helmet. Because of the tighter, brighter beam I can scout specific spots on the trail as easily as turning my head.

I almost bought 2 of the MS so I could do 1 bars/1 helmet but I'm really glad I didn't. On milder sections of single track I turn the MS to low to conserve the battery and then switch to high for the technical sections or descents. I've purchased another NR battery to use as a backup but so far have only had to switch it once.

The temperatures for the 2 rides were: 26 deg. and 14 deg. Yes, that's Fahrenheit! So far I haven't maxed-out the battery so I don't know the true time to empty. But in the two rides that I have ridden, both 2 hours long, temperature doesn't seem to have affected the MS battery too much.

Pros:
Great light beam
bright 
small thin cord
lightweight battery

Cons:
stiff cord
crappy straps on the helmet mount (I cut them off an used my NiteRider straps)
o-rings tend to let the light slip on really rough trail sections


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## HubbaMan (Feb 3, 2004)

ortelius said:



> No way you could run it for 6+ hours on high. Around 3:30 max.
> 
> If it lasts so long on high, there is only one explanation: there is something wrong with it and it is probably driven with substantially lower current as it should. It also means you are getting much less light from it as you normally would.


Indeed, as it is still running now 8hrs later.


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## [email protected] (Oct 17, 2009)

the light should be noticably lower in intensity.


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## [email protected] (Oct 17, 2009)

the light should be noticably lower in intensity.


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## [email protected] (Oct 17, 2009)

the light should be noticeably lower in intensity.


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## [email protected] (Oct 17, 2009)

the light should be noticeably lower in intensity.


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## [email protected] (Oct 17, 2009)

Sorry, I am trying to figure how to delete that mess.


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## HubbaMan (Feb 3, 2004)

[email protected] said:


> the light should be noticably lower in intensity.


Given the time frame between uses, and my inexperience with night lights I have a hard time assessing this but I'm pretty sure you're right.

9hrs later and still going ...

I think the reply mentioning that it cooked the first time the light was used is correct


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## [email protected] (Mar 28, 2007)

HubbaMan,

You've probably burned out one of the current sense resistors (see: http://forums.mtbr.com/showthread.php?t=527707 for way more info than you want). If you don't know how to do surface mount soldering (or have never soldered anything), you should try to return it. The MagicShine doesn't try to regulate or monitor the temperature of the lighthead, and as most of us learned when we were young, stuff that gets really, really hot burns up. LED lights without some sort of thermal regulation burn themselves out if there is no air moving over them to cool them. If you get another lighthead and try to repeat this test, keep a fan blowing on the light.

Your lighthead is now running on a lower setting, probably around 150 lumens instead of 700 (the MagicShine never gets to 900 lumens unless something shorts out inside and it's in it's final blaze of glory before it dies). And it's probably drawing 1/4 of the original current, so it might last 9 or 10 hours on a freshly charged battery.

Mark


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## HubbaMan (Feb 3, 2004)

[email protected] said:


> HubbaMan,
> 
> You've probably burned out one of the current sense resistors (see: http://forums.mtbr.com/showthread.php?t=527707 for way more info than you want). If you don't know how to do surface mount soldering (or have never soldered anything), you should try to return it. The MagicShine doesn't try to regulate or monitor the temperature of the lighthead, and as most of us learned when we were young, stuff that gets really, really hot burns up. LED lights without some sort of thermal regulation burn themselves out if there is no air moving over them to cool them. If you get another lighthead and try to repeat this test, keep a fan blowing on the light.
> 
> ...


Thanks for the link, it made for an interesting read!

Yeah, 14hrs later the light is still chugging along just fine, headlamp button is a nice green glow. I've contacted Geoman to see if there is anything I can do.
If that fails, I guess it'll become a winter DIY project. I have limited soldering experience but what the heck, if I'm stuck with the light I've got nothing to lose and might learn a thing or two in the process.


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## fightnut (Jul 5, 2007)

Not trying to be a jerk, but people have to use a little bit of common sense. First, why would anyone just automatically charge it for 4 hours when they first receive it even if the lights are green? If the charger light is green, common sense says it's fully charged, stop charging it.

And why would anyone run it on high for any length of time while it's sitting still, without running a fan on it?. Especially if it's getting "too hot to touch". Common sense says turn it off.

And I'm not necessarily pointing the finger at the OP, this is for anyone that gets this, or any, bike light. Read the instructions. Still not sure of something? Check with the seller or here on the forums.

Anyway, in the end I'm glad you got your problem taken care of (I saw your other post), but if my _jerky_ post can save someone else from destroying their light before they even get to use it, then I can live with being the bad guy


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## bpnic (Aug 14, 2005)

Ride #1 from a "full" battery was 2 hours, green to red. 40 degrees f
Ride #2 from a "full" battery was 1.5 hours, green to red. 25 degrees f.
Neither time did the light appear dimmer than when I started, and I didn't run them down post-ride, or anything like that.
Thoughts?


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## MtbMacgyver (Jan 23, 2007)

bpnic said:


> Ride #1 from a "full" battery was 2 hours, green to red. 40 degrees f
> Ride #2 from a "full" battery was 1.5 hours, green to red. 25 degrees f.
> Neither time did the light appear dimmer than when I started, and I didn't run them down post-ride, or anything like that.
> Thoughts?


The light uses a regulated driver. It'll always be the same brightness until it shuts off. Runtimes will be shorter in colder temperatures, but those runtime seem too short. Sound like something may be wrong with your battery.


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## bpnic (Aug 14, 2005)

MtbMacgyver said:


> The light uses a regulated driver. It'll always be the same brightness until it shuts off. Runtimes will be shorter in colder temperatures, but those runtime seem too short. Sound like something may be wrong with your battery.


Thanks Mac. Should I run the battery down post ride to "condition it", as Geoman stated?


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## lidarman (Jan 12, 2004)

I feel the deja vu...This whole thread is in a loop.


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## bpnic (Aug 14, 2005)

lidarman said:


> I feel the deja vu...This whole thread is in a loop.
> 
> Bpnic, did you read the first few posts?


Sorry Lidar, my bad!
I was just linking an update to my post here last week (#11). I just kinda skimmed the all other posts in between.

I'll shoot Geoman an email.


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## steve66 (Oct 25, 2009)

bpnic said:


> Should I run the battery down post ride to "condition it"


My first ride with the Magicshine, I got about 2 hours before the indicator went red. When I got home, I put the light on the cold front porch, and let the light run down until it started to blink (which took another hour and a half). At that point, I charged it up until the charger went green. From that point on, I get about 3 1/2 hours on a full charge before the indicator light goes red. So, yes, I would let it run down (in a cold environment or with a fan blowing over it) until it starts to blink, then charge it up.


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## Mikhs (May 18, 2006)

bpnic said:


> Sorry Lidar, my bad!
> I was just linking an update to my post here last week (#11). I just kinda skimmed the all other posts in between.
> 
> I'll shoot Geoman an email.


I don't think you owe anyone an apology for updating your original reply with more information.

My ride last night was the same temp as your second ride, and I got the same time from green to red, 1.5 hours.
My run time is definitely getting shorter as the temperature is getting colder on my present battery. 
Defective battery or we got what we paid for? Time will tell.


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## bpnic (Aug 14, 2005)

steve66 said:


> My first ride with the Magicshine, I got about 2 hours before the indicator went red. When I got home, I put the light on the cold front porch, and let the light run down until it started to blink (which took another hour and a half). At that point, I charged it up until the charger went green. From that point on, I get about 3 1/2 hours on a full charge before the indicator light goes red. So, yes, I would let it run down (in a cold environment or with a fan blowing over it) until it starts to blink, then charge it up.


I like it. Thanks Steve.


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## gmcttr (Oct 7, 2006)

I did a run time test last night at 21F with a breeze to see if this reduced the runtime from testing at warmer temps.

I set the battery outside 10 minutes before testing which left it cooled but not down to the ambient temp when the test started.

The indicator light changed to red at 3hrs 10 min. 30 minutes later the light dimmed and started a fast flash.

This is about the same runtime to red as I got testing at 70F. The runtime after red was slightly shorter.

21F does not appear to significantly effect runtime. I suspect you have another issue if you are getting short times with temps in the 20's.

I agree you should try running it down all the way and a full charge. You have nothing to lose and may save getting a replacement.


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## isleblue65 (Sep 5, 2009)

My first ride on a fully charged new battery last Monday was about 90 minutes before the light turned red. It was 18 deg. F out. My second ride will be this coming Monday and it is supposed to be around 10 deg. F. I hope the run time improves even though it will be colder.

My older MagicShine battery that was powering my helmet light was still going strong on high setting at the end of the ride, and still green.


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## jaewannabe (Jun 4, 2009)

My last ride the outside temp was 10 to 15 which made one of my lights "act" differently after about 1 hour when i turned my light off, the indicator showed red but when i turned it back on it was green again. It operated fine for the rest of the ride, aprox 3 hours of being on, and indicator did not turn red while light was on. So the temperature change didn't seem to effect the operation of the light.


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## mtb_robs-x (Dec 13, 2009)

would anybody want an 8hr (9hr) battery ?
or 4.5hr for 2 lights ?


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## isleblue65 (Sep 5, 2009)

I wouldn't need that much battery runtime, but it would be handy for 24 hour racing!

Update on the red indicator light: When I got home from that ride I turned on both Magicshines. Both lights were green (after they had warmed up to room temperature) and both lights ran for 3+ hours before turning red and shutting off. 

I fully recharged both lights and went on an extremely cold night ride Monday night (-3 deg F). Both red indicator lights came on 20 minutes into the ride. I left the lights on high power and 2 hours later both lights were working at 100% and the red lights were still on. 

I plugged them in for a minute at home last night at room temperature and both green lights were on.

So cold weather does cause the red indicator lights to come on, but it appears that this has no relation to actual battery condition -- rather it is the result of the light head getting so cold that it causes something to switch from green to red indicator LEDs.

This is good because it appears that very cold conditions do not unreasonably shorten runtime on these batteries, but bad because you have no accurate indication of battery life. I would not want to be stuck out in the woods at 0 deg. F. and have both lights turn off because I have learned to ignore the red indicator light - which does not mean the battery is low early on in a ride.


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## mtb_robs-x (Dec 13, 2009)

freezing battery,
rule of thumb, for -20C or colder, min, double the capacity.

so you have at least 35% + charge, left, 
since , when discharged, the battery freezing point is higher,
same with lead acid battery, a discharged battery will freeze much earlier.

li-ion, at normal temp, should be best, only discharged 75-80%
at low temperature half of that, once in discharged down to 90% in sub freezing temp,
ireversable damage occurs, and battery life is down the tubes,...

so for the magicshine, down to -15C with 25% + charge left, should be ok,
for 1/2 or less lifetime. the indicator is probably in the light head,
found even the multi led fuel gauge, useless in cold weather.
working on a solution for that, but be for military application, due cost and spec,
think rescue and special ops, too. This issue, won't become standard, aka applied in general field, and approved, till complete new battery technology be deployed,
what would entail, non fluid, non ionasation tech, carbon solid tech, we might not even see it in our lifetime, due cost. for the general public, a cheaper silicon-alternative (not silicon) organic battery be the shiznik.


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## isleblue65 (Sep 5, 2009)

My helmet mounted MS battery is in my Camelbak, so that one at least has an additional layer of insulation on top of the canvas case. My bar mount battery pack is mounted to the stem in the canvas case, so not much insulation there. On my first ride, that light turned red before my helmet light did.

I think I need to look into some kind of neoprene insulating case for my batteries, or put a hand warmer in there on really cold rides.


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## pimpbot (Dec 31, 2003)

*Maybe....*



isleblue65 said:


> My helmet mounted MS battery is in my Camelbak, so that one at least has an additional layer of insulation on top of the canvas case. My bar mount battery pack is mounted to the stem in the canvas case, so not much insulation there. On my first ride, that light turned red before my helmet light did.
> 
> I think I need to look into some kind of neoprene insulating case for my batteries, or put a hand warmer in there on really cold rides.


... keep it in a fanny pack around your tummy under your coat. It won't freeze there.

Dang, you folks are hardcore if you're out night riding in -20C temps. I'm a big fat wuss from sunny California, and won't go out if its under -5C or so (28F?). Then again, I podiumed in a race because everybody else dropped out when it got over 105F. It was a sufferfest, I tell you what. I almost dropped.


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## DeeEight (Jan 13, 2004)

Anyone opened the battery pack to see what capacity cells they used? I bought one of the magicshine tactical lights from geoman and the 18650 cell they included from the factory in the kit is a 2200mAh capacity (and allows a claimed 40 min run time on high).
I know that size cell comes in 3000mAh varieties so an obviously solution to the runtime issue is to change the batteries you're using in the pack to ones with a third more capacity, and you'll add another hour to the runtime.


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## lidarman (Jan 12, 2004)

DeeEight said:


> Anyone opened the battery pack to see what capacity cells they used? I bought one of the magicshine tactical lights from geoman and the 18650 cell they included from the factory in the kit is a 2200mAh capacity (and allows a claimed 40 min run time on high).
> I know that size cell comes in 3000mAh varieties so an obviously solution to the runtime issue is to change the batteries you're using in the pack to ones with a third more capacity, and you'll add another hour to the runtime.


I didn't completely tear apart my cells and look at the specs but I measured the current on high mode for a MS light at 1300 mA (that is the current from the pack to the headlamp). That battery pack gave me 3 hrs at that current so do the math. Two cells in series times two in parallel.


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## mtb_robs-x (Dec 13, 2009)

*2hr 45min min*

power meter showed around 9.5w
the voltage and current will fluctuate,...
li-ion should be used to 80%
the battery can do 1.3a, aka less than 0.5C for the amp hr.

3.7v nominal x 2.2ahr x 4 = 32.56whr *0.8 / 9.5w = 2:45 hrs
to count on at room temp, in dry, fully charged.

now I'am shure you can get 3:20 out of a fresh new one, under ideal contitions,

for cold weather , below 0C, but above -18c, use 73%, 
the actual numbers, should be actually measured. 
my discharger, has an fan, don't like the noise, but remind me to do a full cycle run,
incl. freezer, and of course you won't get half the runtime on double the load, aka 
plugging in 2 lights on 1 battery, higher load , less runtime, the ahr go down.

also run time might fluctuate, mean you'd seam to get longer runtime,....
because when LED's heat up, the circuit, usually throttles the current,.... more run time,
think that was also a problem getting good readings with the betty light, since it would heat throttle, before measurement was complete, due not riding conditions,...


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## moggy82 (Jan 30, 2009)

lidarman said:


> I didn't completely tear apart my cells and look at the specs but I measured the current on high mode for a MS light at 1300 mA (that is the current from the pack to the headlamp). That battery pack gave me 3 hrs at that current so do the math. Two cells in series times two in parallel.


Is that at 7.4v (upto 8.5v)

3000's are very low draw but would probably cope in the 2s2p format. However the cost of those will come to 2/3 price of a new battery so not really economically viable.

I'd just wait for the next magicshine type of light to come out, there's bound to be one. A triple XPG or SSt-50 based light.

and RobX you seem to have done the math but what capacity battery did you come to.

assuming no losses 3.33hours x 9.5w = 31.66 WH / 7.4v (nominal) = 4.27/2 cells = 2140mAh so prob 2200mAh.


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## mtb_robs-x (Dec 13, 2009)

*7.4V 2S2P 4.4ah*

7.4V 2S2P 4.4ah

since the 2200mah are the cheapest , most available cells,...
some , probably get more out of them, but no garranty.

and doubling the capacity,..... doubles the charge time,...
I don't want longer charge time,.... I want faster charge time.

my current setup for MS, 2x MS on handlebar
bottle battery 82Whr 14.8V with voltage adapter, 4hrs+
for single light , that be 8 hours plus
also working on a monster,.... 171whr bottle battery, less than 2lbs
would be able to run my 35W halogen at 52W for 3hrs, ~2000 lumen,
and if I add one 5w + LED, it be white light instead of yellow.

and RobX you seem to have done the math but what capacity battery did you come to.

assuming no losses 3.33hours x 9.5w = 31.66 WH / 7.4v (nominal) = 4.27/2 cells = 2140mAh so prob 2200mAh.[/QUOTE]


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## dapedaler (Dec 26, 2009)

[email protected] said:


> HubbaMan,
> 
> You've probably burned out one of the current sense resistors (see: http://forums.mtbr.com/showthread.php?t=527707 for way more info than you want). If you don't know how to do surface mount soldering (or have never soldered anything), you should try to return it. The MagicShine doesn't try to regulate or monitor the temperature of the lighthead, and as most of us learned when we were young, stuff that gets really, really hot burns up. LED lights without some sort of thermal regulation burn themselves out if there is no air moving over them to cool them. If you get another lighthead and try to repeat this test, keep a fan blowing on the light.
> 
> ...


Cooling is definitely a weak point of the MagicShine. It should NEVER be run on high sitting on your workbench unless you have a fan blowing on it. The life (brightness) of the LED itself is greatly reduced if allowed to run at too high of a temperature, not to mention the control circuit.


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## electrik (Oct 22, 2009)

I can also somewhat confirm a shorter "green to red" run-time in the cold(-5c to -10c). My suspicions and maybe somebody with more knowledge can say is that the control mechanism isn't set for the voltage discharge curve in a cold environment. It is weird, I actually get a strange disco effect for a while, where the button led seems to flux between red to yellow to green like some lava lamp. However i haven't run it down past 3hr mark in the cold but if the light is supposed to only last 10 minutes on high with the red led on, I can say it lasts at least twice as long and in fact will switch back slowly to green if you leave the light on low for a few minutes.

Does the MS led turn solid yellow under some circumstance?


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## MtbMacgyver (Jan 23, 2007)

Yes, the indicator light will turn red sooner when the battery is cold. The magicshine controller doesn't measure the temperature of the battery pack and compensate for that in any way. The color of the indicator is simply based on the voltage level coming into the light head. The runtime on the battery will be shorter in cold conditions, but not as short as the indicator light implies. 

This doesn't help with bar mounting, but put the battery in your jersey pocket under your coat instead of in your hydration pack. Then it'll stay warm and you'll get normal runtime and indicator light function.


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## isleblue65 (Sep 5, 2009)

I ride once per week at night in sub 15 degree weather and can confirm that the red indicator light on my bar mounted light always turns red within 20 to 30 minutes. At first I was concerned about it, but then I started to ignore it. I've gone 2 hours with the red light on and no loss in light output. After the ride with the bike in the house and warmed up for a few hours, the light is back to green when turned on. It appears that the controller is affected by temperature, but this is no indication of battery life. 

I can't see the color of my helmet mounted MS while riding and the battery pack for that one is in my Camelbak, so can't comment on this.


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