Have a new m43 i have been playing with. Right off the start i noticed something strange. I put in 4 brand new and fully charged (to same level in same charger) Panasonic NCR18650PF (10A). After only a few minutes of use the battery level indicator light dropped a step, continued to use the light and test it, noticed that it dropped once more and i was surprised as i thought battery life would be better. Did not think to much of it, maybe the battery level indicator was calibrated for a different type of cell, so continued using the light on and off for a week.
Put my 4 cells in the charger today. 3 of them took 1600-1900 mah. One of them was very quickly fully charged at 388 mah. I was quite surprised. I heard of the dangers in using differently charged cells in such a light that is wired parallel. I am wondering what is wrong. The light? The cell? The user?
I have an Xtar VC4, cells are brand new from trusted supplier. Light is new from trusted seller.
Did one battery not have contact?
What if that battery suddenly did get contact? Would it rapidly discharge and damage?
Need some ideas on what to troubleshoot. I have an Imax B6 hobby charger. Could discharge all cells to check that they hold the equal amount of energy. Or shove them in the m43 and run it for a while, then check voltage over each cell.
Maybe this is the reason of the strange battery level indicator?
If one battery did not make contact, then this means that only three cells were used to power the M43. This would significantly increase current draw per cell, hence voltage sag as well. The PF is also an older type cell with more voltage sag than 30Q or GA, so this could explain how the battery indicator quickly showed depletion of the cells (blue>green>red). What kind of PF do you use? Rewrapped or solder blobbed? I would start by trying different cells, preferably the ones that are advised.
Edit:
Tape the inside of the battery tube, and mark each bay 1, 2, 3 and 4. Also mark the cells 1, 2, 3 and 4. Also note which cell was hardly depleted. You can check whether it is be a battery problem by inserting that cell in a different spot in the battery tube. You should be able to figure out whether it’s a battery problem, an M43 problem, or perhaps a charger problem…
If you are using the unprotected PF battery, it has a flat top. So while most of my PF does stick out a little, maybe one of your battery is not making good contact with the light. You should try to using some button top battery to check.
Well, i remember reading it on here somewhere. To my own knowing it is when the batteries are in series that this is a danger. However, i always want to run equal cells anyhow.
Thank you all for the quick feedback. Fantastic forum this is!
I am using this cell Panasonic NCR18650PF 2900mAh - 10A - 18650 - Li-ion - Oplaadbare batterijen | NKON . It is listed my mtn as a recommended cell. Not sure if mine is different somehow? The cells barely peak over the edge of the tube before screwing them together. Maybe 1 or 2 mm tops. I have put them back in and run them for a while on the highest double click setting in the mimimalist UI (3A). I do notice that the difference between that and turbo is really small, should be a larger difference in my opinion. Barely visible.
After running it for some minute i took the cells out, noting the positions in the tube and the cells voltages. Light said 5 flashes indicating correct voltage with fresh batteries. 4.05-4.2 volts. Each cell measured between 4.182. and 4.189 after a nights rest after charge. After this minor use light says 3 flashes inticating 3.7 to 3.85 volts. After some minutes rest it indicates 4 flashes 3.85-4.05 volts. Strange!
Cells after minor use
cell1 3.958
cell 2 4.185
cell 3 4.186 - This is the cell that was left charged previously but possibly in another position.
cell4 4.189
Putting them back in the charger i received the same answer. 3 cells had not seemed to be used by the light as they received basically zero charge. The one cell was munching mah happily until 520mah . This time it seems only one cell was being used? I noted the batteries position in the tube this time, forgot that yesterday. I am guessing my batteries are too short? But they are recommended, or i have some different version that i do not know about.
Doesn’t the M43 require button top cells, or you risk losing contact? The cells Mt. Electronics recommends are button tops. The PF’s he has listed for recommended cells are button tops. OP bought flat tops.
Probably will get new button tops. Was unaware that the panasonic one had different versions as the “flat top” looks a little like a button top. Rookie mistake i guess, new to 18650s. These batteries felt like quite good value in relation to their specs, but i understand why now. They do however work great in my other single cell lights, and at the price they seemed hard to beat.
Is neomagnets a bad solution? To “create” a button top. Hehe… feels like a hack, wont try this. Will stick to new cells.
Thanks for the help! Will fix this asap, and might post back when i am blown away by the real turbo mode…
Don’t use magnets on the M43. When you screw it together the magnets may shift and could cause a short. Either get button top cells or do what Will says and add a solder blob to the top.
Panasonic doesn’t have a button top version, nor do any of the other manufacturers. Button tops and protection circuits are added by 3rd parties. Companies like Keeppower and Efest don’t make cells, they buy in bulk and re-wrap Panasonic/Sanyo, Samsung or LG cells with their name on the wrappers.
Now I have read it too somewhere online, because you have written it. Does that make sense? :laughing:
Everyone says about the dangers of cells in series.
Now should you use cells that are different in capacity, internal resistance and of different charge in a parallel light? No
of course not.
Have all identical cells, charger 3 of them to 4.2V, charge one to 3.9V only
Put the cells in the light for and hour. You will see all cells balance, so all 4.2V cells will drop to lower voltage and
the 3.9V will rise in voltage to match all other. That is quite ok.
That is what happens normally, if the contact is good and all cells are identical.
I personally have soldered some brass caps to my flat top cells.
And of course do not use flat tops, only button tops, the light is it made that way to have issues with the flat tops.
There is a mechanical anti-reverse (at least on my model there is I do not know if there still exists) which if you put the
cells in reverse, meaning the “flat” bottom, it is too wide to make contact with the brass ring and it wornt work.
I am talking from experience, I did put the cells in reverse. Beacon button did not work, I did not even had to try to turn on the light,
just looked at the OFF mode beacon light not working.
This feature was totally cloned by other manufacturers.
Putting a fully discharged cell in parallel with a few fully charged cells (especially hi-capacity low ESR cells) poses the risk of exceeding the manufacturer’s maximum rated charge current, for a short duration, on that discharged cell.
Likely not dangerous at all due to the relatively short duration that excessively high current will flow (if the cells are quality), and any quality cell will vent in a safe manner if things are drastically exceeded; however, it could potentially reduce the discharged cell’s cycle life / capacity a tiny bit due to the excess current causing a higher quantity of once free / mobile ‘ions’ becoming permanently fused / embedded to the battery’s anode material, thus are no longer free to move as charge carriers (not dangerous, just reduced capacity / cycle life & higher internal impedance). If done only once, the negative effects would likely be within allowable cell-to-cell manufacturing variance, and thus statistically irrelevant… If done repeatedly, it would most definitely be measurable over the cell’s expected cycle life span.
The max rated charge current is not only to prevent excess heat production / thermal runaway (most common danger & unlikely in this specific scenario due to the relatively short duration), the max charge specification is also specified to limit uneven charge state within the rolled laminations of the cell, which would cause faster lithium ion plating of the Cathode material in the localized areas of faster charge (Potentially dangerous in very poor quality cells due to increased dendrite formation, but mostly just reduces capacity / cycle life & increases internal impedance and self-discharge rate).
A quick rough check to see whether one of the battery springs is sagging a bit, would be to put all the batteries in the carrier & see how even the tops are to one another in reference to the top of the battery carrier. Proper length batteries should sit nearly flush with the end of the battery carrier, if not a millimeter or so proud of it. The springs allow for approximately 5 mm of displacement, around 2 mm are taken by the positive terminal of the driver PCB, so that leaves just over 2mm of height above the top of the battery carrier for the batteries to stick out, until you’ll run into compressing the springs flat & not being able to screw the head all the way on.
The converse is also true, if your batteries positive terminals sit much more than 1mm below the top of the battery carrier, you’ll likely have poor connection issues due to a low amount of spring force keeping the battery against the positive plate in the head. If the battery positive terminal sits below 2mm, you’ll definitely have issues with connection…
Yes, agree’d, and also do not attempt to solder on brass pucks to the positive terminal of flat tops, unless you’re extremely quick, else you risk compromising the plastic vent’s operation, where it will likely no longer be sealed, causing corrosion & reduced battery life over time as gasses leak out & the electrolyte dries up.
I will not run flat tops in this light. Good that i did not continue using it and checked on here. I will not experiment on 18650 with soldering yet since it is my first encounter with these batteries, so button tops from trusted dealer will be my solution. I need some extra 18650s anyway so it is the best option. My flat tops can be used elsewhere.
Just thought i would come back with the results. As expected everything works fine! 18650 Newbie mistake with the flattops. Got the NCR18650GA and they hold a lot of energy which is nice. Flashlight performs better than ever on Turbo and voltage meter gives a more fair assessment in relation to expected battery life.
So everything is good thanks to all the quick replies. M43 is a great light at the current price.
