Lights. CREE XML XM-L T6 / U2 etc Thread

[potsy]

I ordered another pack to go with the solarstorm, just need to get some more batteries, will probably go for some of the high power ones as this light will need more juice.

Now, about these rear lights...

 

[Supersuperleeds]

Quite happy with my little commuter L2-T6 lights with the angel eye feature. Very visible from the side. As I am running both off a splitter and one battery, one of the lights records the green light for battery status but the other one either shows green for a short time, then goes red, then the indicator switches off. Both lights remain on, I think that having two charge sensors on the one battery just throws a wobble.

It's a much tighter beam than the normal T6/U2 lights, so doesn't throw tonnes of light everywhere.

Are they the £12 ones? if so where did you get them, I fancy another front light (or two!)

 

[Lanzecki]

Just got a cree t6 and im impressed, it got me thinking about a rear light that would work from the same battery pack with a y splitter. Anyone know of any (cheaper) alternative to the magicshine rear lights?

Try this : http://www.amazon.co.uk/Smart-Lunar-2X1-Watt-Rear/dp/B00452O6LI/ref=sr_1_5?ie=UTF8&qid=1389781946&sr=8-5&keywords=smart bike light

I wouldn't take power from your cree light. They eat battery, you don't want to loose both lights if the battery goes flat. This one's blindingly bright. I've had mine for a while. It's a bugger to open, but that not a bad thing as it's going to be very waterproof, and the AAA batteries last a really long time.

Thinking about it the Crees use 2 or 4 parallel cells (the 4 cell units are 2 pairs of parallel in series) giving 4.2 and 8.4 Volts respectively. Well the 3 T6 lights I have use these configurations.

Most rear lights I've had/seen use 2-3 AA's or AAA's these give 1.5 Volts each cell giving between 3v and 4.5 volts each. So there is an issue with under/over driving the rear lights. Over driving LED's sounds a death knell for the control circuit, and LEDS.

Plus... The 18650 batteries in modern lights are not AA size. They are not like re-chargeable AA or AAA's they are slightly larger then AA's and give a higher voltage then AA's. Part of their design is a control circuit that controls the charging and how the power is supplied to the lights. This control circuit control's the charging and discharge to avoid over charging and over depletion. Interfering with or by-passing this control circuit can result in dead batteries from over draining, and even worse fire/explosion from over charging.

You will remember the days of ni-cad batteries where you charged them for X hours. These days are mostly long gone apart from things like cheap shavers etc.

li-po chargers will not charge Ni-Cad's and vice versa. One of the positives behind the size difference is that 18650's will not go into ni-cad chargers.

That said, most laptop batteries use these 18650 batteries. With some knowledge it's possible to remove these batteries to make your own packs. Do go and buy a controller as mentioned above and a properly rated li-po charger.

Please treat Li-op batteries with kid gloves. Any rough treatment can result in catastrophic failure of the cell. Often dropping then can cause internal damage. These cells are not like your average AA.

 

[fossyant]

Are they the £12 ones? if so where did you get them, I fancy another front light (or two!)

If you check a bit further back they are from lightmalls.com I will do a link tonight when home

 

[Supersuperleeds]

If you check a bit further back they are from lightmalls.com I will do a link tonight when home

@fossyant Thanks, I've found them

 

[tincaman]

This one?

 

[fossyant]

Yes they are the ones. One has a red interior and one model is orange.

 

[Supersuperleeds]

I think I am going to need an extender for my handle bars

 

[stumpy66]

Try this : http://www.amazon.co.uk/Smart-Lunar-2X1-Watt-Rear/dp/B00452O6LI/ref=sr_1_5?ie=UTF8&qid=1389781946&sr=8-5&keywords=smart bike light

I wouldn't take power from your cree light. They eat battery, you don't want to loose both lights if the battery goes flat. This one's blindingly bright. I've had mine for a while. It's a bugger to open, but that not a bad thing as it's going to be very waterproof, and the AAA batteries last a really long time.

Thinking about it the Crees use 2 or 4 parallel cells (the 4 cell units are 2 pairs of parallel in series) giving 4.2 and 8.4 Volts respectively. Well the 3 T6 lights I have use these configurations.

Most rear lights I've had/seen use 2-3 AA's or AAA's these give 1.5 Volts each cell giving between 3v and 4.5 volts each. So there is an issue with under/over driving the rear lights. Over driving LED's sounds a death knell for the control circuit, and LEDS.

Plus... The 18650 batteries in modern lights are not AA size. They are not like re-chargeable AA or AAA's they are slightly larger then AA's and give a higher voltage then AA's. Part of their design is a control circuit that controls the charging and how the power is supplied to the lights. This control circuit control's the charging and discharge to avoid over charging and over depletion. Interfering with or by-passing this control circuit can result in dead batteries from over draining, and even worse fire/explosion from over charging.

You will remember the days of ni-cad batteries where you charged them for X hours. These days are mostly long gone apart from things like cheap shavers etc.

li-po chargers will not charge Ni-Cad's and vice versa. One of the positives behind the size difference is that 18650's will not go into ni-cad chargers.

That said, most laptop batteries use these 18650 batteries. With some knowledge it's possible to remove these batteries to make your own packs. Do go and buy a controller as mentioned above and a properly rated li-po charger.

Please treat Li-op batteries with kid gloves. Any rough treatment can result in catastrophic failure of the cell. Often dropping then can cause internal damage. These cells are not like your average AA.

Thanks for the info

 

[fossyant]

Just got a cree t6 and im impressed, it got me thinking about a rear light that would work from the same battery pack with a y splitter. Anyone know of any (cheaper) alternative to the magicshine rear lights?

There are just two choices. The Magicshine 818 and the C&B Seen rear light. I have both. The magicshine is quite small, and will do piggy back off the main lights battery. But, they do have an issue of switching off if vibration is bad as it causes the on/off ring to rotate and switch off. I switched to the C&BSeen lights, but if you piggy back one of these, then I would recommend you sort out some of the packs we mention above, I.e. Buy the 18650 batteries, and the case. You will need the run time as the light is quite power hungry compared to the magicshine as it runs two high powered LEDs and even having one on, and one flashing, it does eat batteries. I ran two of these off one 5600 pack which is probably double the cheap Chinese packs.

I quite like the C&B light, you have a good choice of modes, and the flashing is alternating between the two LEDs, so you don't ever have no light, so from a distance looks like pulsing, rather than on, off. It is, however, a big light unit and quite heavy.

 

[fossyant]

PS all of the lights here are very very bright, so please make sure that are angled down if you are commuting and not on max. The ones I'm now using on the front are a very tight beam, so don't dazzle drivers but would be too much on full.

I've had just one comment tonight about my C&B rears, and that was from a monkey passenger in an old banged up fiesta, despite them pointing towards the road, "they are dazzling" he shouted as they flew past.

 

[stumpy66]

Thanks for the info fossy, this thread has been a good read

 

[fossyant]

Have a good read through it. There are also a couple of other sources I use. Bike radar MTB buying advice on lights, has its own thread. And also MTBR light threads.

But the summary is here, just read through it, it's worth the time.

The biggest change I've noticed over the years are, these Chinese lights are bad, dangerous too cheap, then the MTB crowd have got into them and really rate the lights, and are able to be modded. The biggest issue has been crap batteries, but that was sorted by making your own pack at first, but now there are the cases for quality batteries to be fitted. Winner as the lights are very cheap. It's the batteries that cost now, but nothing like what the big manufacturers charge for their lights.

PS, be careful with road use please, and I will always say this.

 

[Lanzecki]

Ohh look at something like http://www.amazon.com/Angle-MagicSh...e=UTF8&qid=1389825697&sr=8-4&keywords=t6+lens

goes from spot to a wide beam.

 

[Lanzecki]

As per this post by a really smart bloke called lanzecki :

http://www.cyclechat.net/threads/my-first-time-riding-in-the-dark.143062/post-2757166

The Lens gives this effect from standard :