Charging cheap 2400L light

GarryM

I've just bought one of these on eBay:
3x CREE 2400 Lumens XM-L T6 LED +2x XPE R2 LED Bike Bicycle Cycle Lights 6400mAh

No instructions came with it and I can't find anything on the forum. Does anyone know how long it should take to charge the battery? I'm reluctant to just leave it on charge in the hope the little green light on the charger will eventually go out!

Thanks in advance.

t.m.h.n.e.t

Have a look at the output of the charger. Probably in the region of 4-6hrs though

GarryM

Thanks. I don't have it to hand but will look this evening. At the risk of sounding very dim, how do I calculate how long to charge it from the output? Is it simply 6400(mAh)/output of charger?

t.m.h.n.e.t

GarryM wrote:

Thanks. I don't have it to hand but will look this evening. At the risk of sounding very dim, how do I calculate how long to charge it from the output? Is it simply 6400(mAh)/output of charger?

It's something like capacity / 1000 = 6.4amp maximum charge.

But I honestly can't see the charger that's bundled with the lights putting anywhere near that out.

GarryM

Thanks. In case anyone else stumbles upon this looking for an answer: the charger with mine outputs 1A. An on-line calculator http://www.csgnetwork.com/batterychgcalc.html tells me that with a 20% efficiency loss (apparently to be expected) it will take just over 7.5 hrs to charge my 6400mAh battery fully.

t.m.h.n.e.t

GarryM wrote:

Thanks. In case anyone else stumbles upon this looking for an answer: the charger with mine outputs 1A. An on-line calculator http://www.csgnetwork.com/batterychgcalc.html tells me that with a 20% efficiency loss (apparently to be expected) it will take just over 7.5 hrs to charge my 6400mAh battery fully.

Nice find

Ouija

GarryM wrote:

I've just bought one of these on eBay:
3x CREE 2400 Lumens XM-L T6 LED +2x XPE R2 LED Bike Bicycle Cycle Lights 6400mAh

No instructions came with it and I can't find anything on the forum. Does anyone know how long it should take to charge the battery? I'm reluctant to just leave it on charge in the hope the little green light on the charger will eventually go out!

Thanks in advance.

Got a couple of these. The little green light doesn't go out. It's red when the battery needs charging and switches to green to tell you it's charged already......

diy

You have to be very careful charging these since very few of them have balance circuits and thermal controls, so if you are going to leave it charging 7 hrs + then you need to think about using a time switch and some basic fire proofing. The risk with these packs is that over time the cells will get out of sych and hold different levels of charge. Simple chargers either work just in phase 1 or just in phase 2. If you keep charging a fully charged cell in phase 1 you get a fire risk.

Charging in biscuit tin on a time switch is the best option, away from any combustibles. This lack of safety features is the primary reason why these lights are only sold in the far east. That aside you get very powerful lights for not much cash.

diy

worth reading this too:
viewtopic.php?p=17939012#p17939012

andy_s_t

I have some Cree lights and they came with a charger that flashes red when charging and then changes to green when charged. I haven't taken the charger apart and checked it, but I'm assuming that it has some simple detecting circuit in it. If yours is like mine it'll be powered by A123 style cells, which are very stable lithium based cells, in fact they are what are used in your laptop battery etc. so no need to worry about them. I did stick mine on a far more intelligent charger (a very expensive shulze) not long ago that I use for balancing and charging lithium polymer cells that I use elsewhere, the cells were in very good health and were very well balanced, so I have no issues about just using the supplied charger.

diy

in a laptop they are connected to a high quality charge and control circuit. 18650s are fairly stable but you should not leave them charging unsupervised for long periods