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Old 10-10-13, 12:57 AM   #1
Grishnak
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CREE XM-L XML T6 LED Headlamp

Hello,I have a CREE XM-L XML T6 LED Headlamp thats runs from two 18650 rechargabe batteries.Can I also run it from a 6volt lead acid sealed battery?
thanks.
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Old 10-10-13, 06:55 AM   #2
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Hello,I have a CREE XM-L XML T6 LED Headlamp thats runs from two 18650 rechargabe batteries.Can I also run it from a 6volt lead acid sealed battery?
thanks.
Probably not. The Li ion batteries produce 7.4 V and the circuitry in the light may have a protection circuit that won't let it operate at that low a voltage. But replacement Li-ion battery packs are dirt cheap.
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Old 10-10-13, 12:24 PM   #3
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OK,thanks mate.i just have an old lead acid on a belt pack that i wanted to use up..
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Old 10-11-13, 04:23 AM   #4
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??? if you have all the parts lying about then give it a try, let us know how it works out. . .
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Old 10-11-13, 09:15 AM   #5
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YEP,will do.
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Old 10-11-13, 11:54 AM   #6
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Why do you want to do this? LiIon batteries are better in almost every way.
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Old 10-11-13, 04:13 PM   #7
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If they are wired in parallel you can buy a holder that will allow more batteries for a longer run time.
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Old 10-12-13, 12:32 AM   #8
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Why do you want to do this? LiIon batteries are better in almost every way.
Yes the batteries are better,but i like the lead acid sealed on a belt.I tend to hang a lot of other bits and pieces off it when i`m beach fishing.

I`ll just have to wear the belt with no battery.
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Old 10-16-13, 05:15 AM   #9
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??? if you have all the parts lying about then give it a try, let us know how it works out. . .
It works!,It also runs on a single 18650.If the manufacturer estimates 3 hours runtime on the 2 x 18650`s,approx how long will i get on a 4 AH 6 volt?
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Old 10-16-13, 01:29 PM   #10
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Probably not. The Li ion batteries produce 7.4 V and the circuitry in the light may have a protection circuit that won't let it operate at that low a voltage. But replacement Li-ion battery packs are dirt cheap.
The Li-ion battery probably starts at about 8.4 volts -- by the time it hits 7.4 volts it's around half discharged.

That said, the 6v Pb battery probably starts at 6.5 volts or so, and is nearly dead at 6.0 volts.

I imagine the Pb battery will work when fully charged, but the protection circuit will probably kick in before it's fully discharged (though it might go all the way down to 6.0 volts -- that's the lowest you can safely discharge two li-ion cells, but even that's pushing it further than is ideal.)
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Old 10-16-13, 11:57 PM   #11
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But it runs on one,thats 3.7 volts?
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Old 10-17-13, 06:34 AM   #12
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It depends of the driver of your bike light. Many drivers for XM-Ls have operating voltage from 3 volts to 4.5 volts. You can however swap a buck driver, the ones used for two cell in series flashlights. Its operating voltage is 6 volts to 9 volts.
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