That’s odd. What I do when I receive a bunch of cells is check the voltage first. The four Keeppowers for the L6 from Banggood had the same voltage within 0.002V. Supersweet, and it’s more likely that the cells are of the same batch. I wonder whether your cells were of the same batch; or maybe it’s a QC issue?
I just tested mine. 3.63V and 3.61V in that pair. How do you measure yours to within 0.002? My multimeter doesn't do more than .00 for volts that I can see.
and......the next question on my mind is.. if mine were not from the same batch, is it safe to pair them up considering the difference I have in the voltage from my above test?
4000 count DMM. Meaning it can display values under 4000, such as 3.676V. It cannot display fully charged cells in four digits, only 4.20V. For more accuracy in that region you need a 6000 count DMM.
0.02V difference should be no problem. Only if you have completely different values you could then check the capacity of the cells to see if they match. In practice I can’t imagine that it will be a problem. This is just my take, no doubt others have a different idea…
Thanks hIKARInoob. I think it is time to upgrade my DMM then! I have been in contact with Keeppower the last little while and I have to say, they are really great to deal with and always support their product. They just told me that they make the protected 26650 in flat and button top as the flat top fits much more flashlights and they suggested just now what I already did, and that is to use the flat top on top in the L6 to make it work if I got one of each, which I did.
Cheers man. The consensus seems to be that with decent cells you’re never ever going to have problems, unless you seriously abuse them. But it’s nice to monitor the cells in different ways to have a better feel and understanding of lithium ion. If you have a DMM, you know that 4.2V means full cells, and 3.5 means they’re almost empty.
Cells of the same batch/state means also that charging takes about the same amount of time. When I charge 4 Sanyo GAs from 3.5 Volts to 4.2 Volts, it takes like 5 hours or so. The time difference between the first cell fully charged and the last cell is less than 10 or 15 minutes. If I monitor this regularly with all cells being charged, I get a good idea of what normal behaviour is. So I learn. Also, just feel how warm the cells get during charging; same thing, you know what normal behaviour is.
Cheers! Yeah, it all seems to be good. I do the same thing when I put them on my VC4. I think that is the best way overall to keep an eye on them. Also got another email from Keeppower and they told me that since the battery chemistry is the same, just to charge them together the first time and then use them in series and they will equal out the same, so in my books I'm happy and also thankful that they did not hesitate to reply and help me out.
Yeah, I like Keeppower too for protected cells. P.S. For good fun you can also get a lux meter for as low as 10 bucks or so. You can measure output difference between your CW and NW L6 for example. Knowing the voltage of your cells, you can measure the relation between cell voltage and output. Pretty cool stuff…
Thanks J-Dub.
Got a 12mmX3mm round neodymium magnet between the cells for now, so I could check out the light.
Will hold off till I hear back.
Thanks, Nick
Just when I think I have all the tools I want and need lol.
They’re actually readily available as retrofits (H4 being by far the most common).
For some reason they’re usually keyworded as “bixenon”.
First result on eBay for bixenon even has this gif. showing how they work.
There’s nothing that special about them that makes them any harder to retrofit than “traditional” kits.
Here’s a neat video showing their operation:
At the time I did not have the L6 in my possession. Now I can confirm that that they Do Not work.
I have a magnet between the cells to create contact, so I an able use the light. These are my first 26650 cells. Again, Glad I only bought 2 pcs.
You can get XHP70 versions from China:
https://www.aliexpress.com/item/Ossen-P70-XHP-70-LED-Headlights-H4-3-Hi-Lo-110w-13200lm-H8-H9-H11-HB3/32758687621.html
Only real design difference is the passive cooling. While not as fancy, it should be more fault-proof.
The seller is even honest enough to show how much current they’re driven at.
They also have an XHP50 version: (Note how they have less cooling braid than the XHP70s)
https://www.aliexpress.com/store/product/Ossen-12V-2-8A-R3-H4-40w-LED-Headlights-4800lm-6000k-High-low-beam-XHP-50/1899072_32764203887.html
(For unfortunate people like me with H3 headlights, this is the only option as XHP70s are too big for the opening in an H3 reflector)
I got my second pair of Keeppowers and both came with one flat top and one button top each, so I got them to work in the L6 by having the flattop on top so the driver spring can contact it and the battery that is slightly raised below it. The raised top batteries are only up by a hair, but this works fine in my L6 keeping them under the flat top ones. Maybe you could try switching them around, but looks like maybe both yours are recessed and that won't work.
Yes Both are recessed. Actually the tops are flush but the bottom is recessed. No workie.
Been looking on BG at the 2 versions of the 5200mAh KP’s and neither match what I have received @ 68mm OAL.
Also I can not figure out what the SKU and other number are or mean on my individual boxes the cells came in. Nothing matches or makes sense. No other wording on the boxes.
SKU447221-SEZ0
I think these are the boxes the cells came in. They are too short to hold them properly.
Mine just came in a clear plastic bag in a white box with no writing at all. I guess they just pull them and use any packing available to keep the price down since the battery themselves are labelled.
Just added pics of boxes to previous post.
Yeah, they need to box them for safety. But those must be generic, use whatever is available boxes.
My boxes had a thick white foam wrapped around them as well and arrived undamaged.
Which battery configuration and driver would be best to put triple XHP 50s in this light
2 26650 in series
fet driver with zener diode (see Mtn electronics)
And what reflector will you use ?
^ What Giorgos said… and wire the 3 XHP-50’s in parallel. There are some touting series as giving more output, which may or may not be so, I don’t know, but I do know that if 3 are in series and one blows a bond wire or something then your light goes dark. Parallel will run with 2 or 1 and you’ll have light regardless.
I think I’d mate up 3 spare C8 reflectors, with the orange peel for a smooth beam.