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

[JoeyB]

I just bought a second battery pack for my Cree T6 jobby, doesnt get used much but need the life on the night ride next week

 

[moo]

The cheap Chinese battery packs have between 1500mah and 2500mah, despite claiming more. The average battery pack will get you 1.5 hours run time on high. I get over 6 hours using a Panasonic 6800mah battery pack from hunk_lee.

I'm currently running 2 single Cree lights off the same battery. With over 3 hours run time on high it only needs charging once a week on Sunday. Sure the pack was "expensive" at £28, but not having to charge every 2 days was worth it to me. If going for a long night ride I would need 3 Chinese battery packs for the same run time.

Also:
Cree XML U2 light head (no battery or charger) for £7.59 at AliExpress

 

[tincaman]

This might be ok, Halfords own brand but the battery pack could be a good one.
http://www.ebay.co.uk/itm/141212215493
1200 lumens for £20 delivered
The same seller also has the lower rated Bikehut front lights as well, the 450 lumen one is only £12.99

 

[tincaman]

Well I received this light set today and am impressed so far, its not like the usual Chinese fare. The LED inside is listed as a Phillips Luxeon Rebel one, but you can see the led die and the words XML-T6. The handlebar clamp is very solid with a quick release. Inside the box is a helmet mount, an extension cable, O-ring, cable ties and velcro strap for the battery pack (looks like a 2 cell, 4.2V, claimed 5200mah)The light modes are: Flash (it flashes medium/high without going off), low, medium, high. On the top are a series of very small blue LED's to indicate which mode you are currently on.
The battery pack has a press switch on the end to indicate charge
The beamshape is rectangular, cut off at the top.
I found the original manufacturer and they have this video of the light head
Its a NLTEK Altion

 

[tincaman]

An update on the above:

It a variant of the NLTEK Altion. It runs at 4.2v, the NLTEK website lists the battery pack at 14.4v
There are other slight variations, the battery pack does not have an on/off switch or the extra leds's on the head for battery charge state.

I would like to run this off a 4-cell pack, but all the packs I have are 8.4v, whats the risk of trying this? Would it be that the driver board accepts an input range of voltage do you think?

 

[crazyjoe101]

You can build a 4 cell pack using two two packs wired in parallel. I'm not sure how handy you are with a solder or about the availability of packs or cases though.

Also, my T6 died after about a month so I'm moving on to the spare I ordered, judging by other's reviews of the T6 lights I was just unlucky. The status light is there but the light no longer switches on.

 

[tincaman]

You can build a 4 cell pack using two two packs wired in parallel. I'm not sure how handy you are with a solder or about the availability of packs or cases though.

I have most thing I need to do this including a protection PCB but I much prefer the type of pack with removable batteries

 

[crazyjoe101]

I have most thing I need to do this including a protection PCB but I much prefer the type of pack with removable batteries

There are advantages to charging cells induvidually or in performance matched pairs if I recall correctly, is it something to with that?

 

[tincaman]

There are advantages to charging cells induvidually or in performance matched pairs if I recall correctly, is it something to with that?

Yes something like that, every battery pack I have had has had to be disassembled to remove a duff or unbalanced cell, so the idea is to have a pack which can be charged as normal but have the ability to take apart easily and repair. Also you get to choose the quality of the cells you are using.

 

[stumpy66]

Yes something like that, every battery pack I have had has had to be disassembled to remove a duff or unbalanced cell, so the idea is to have a pack which can be charged as normal but have the ability to take apart easily and repair. Also you get to choose the quality of the cells you are using.

Something like this, i think this is the pack that fossy bought recently http://www.aliexpress.com/item/Sola...tery-case-used-for-bike-light/1314568186.html

 

[tincaman]

Something like this, i think this is the pack that fossy bought recently http://www.aliexpress.com/item/Sola...tery-case-used-for-bike-light/1314568186.html

I have one of those, but the new light unit runs on 4.2v, these packs take 2 or 4 cells to make 8.4v. I was thinking about the risk of trying to run the new light on 8,4v

 

[Lanzecki]

I have one of those, but the new light unit runs on 4.2v, these packs take 2 or 4 cells to make 8.4v. I was thinking about the risk of trying to run the new light on 8,4v

You might get a few seconds before it blows. Don't they do a 2 cell version?

"Compatibility: 2 or 4 pieces 18650 li-ion batteries in any capacity."

There's a fix. The specs say it'll run with 2 batteries. As it's 2 in parallel and 2 in series, it should (don't quote me) take 2 in the right way to give you the 4.2v you want.

 

[crazyjoe101]

If that doesn't work, you should be able to find something similar in a true 2 cell version, and solder two of these together in parallel, and stick the protection in series after them. You could glue them bottom to bottom such that the batteries can be removed and then tape the wiring onto the side to keep it insulated.

On another note @tincaman , are you able to compare the above light to one of the generic T6 copies?

 

[tincaman]

You might get a few seconds before it blows. Don't they do a 2 cell version?

"Compatibility: 2 or 4 pieces 18650 li-ion batteries in any capacity."

There's a fix. The specs say it'll run with 2 batteries. As it's 2 in parallel and 2 in series, it should (don't quote me) take 2 in the right way to give you the 4.2v you want.

Most 4 cell packs are 8.4v 2S2P (2 series 2 parallel) I could make a 4P to get me 4.2v, but I would like a suitable battery holder instead of soldering the pack together. Alternatively source another of the 2 cell 4.2v packs and wire them in parallel with a splitter cable

 

[Lanzecki]

Most 4 cell packs are 8.4v 2S2P (2 series 2 parallel) I could make a 4P to get me 4.2v, but I would like a suitable battery holder instead of soldering the pack together. Alternatively source another of the 2 cell 4.2v packs and wire them in parallel with a splitter cable

Read the specs from that site. It says it'll work with 2 cell. I'm not sure if that'll work 2p or 2s though. Maybe both. Talk about versatile.