I recently purchased a Klarus G35. I really like the light but I am having a problem with it and thought someone here might be able to help me figure out what is wrong. This light will work with either one battery (in the designated slot) or with three batteries. It uses 18650 batteries. I have used three different batteries with the same problem:
LG HG2 unprotected flat top
Olight protected
Sony VTVC6 unprotected button top
The problem is that when using three batteries, they discharge at different rates. The cell in the slot designated for one cell usage doesn’t discharge at all while the other two discharge equally. An example of voltages after use would be :
Cell 1 4.20 v
Cell 2 3.95 v
Cell 3 3.95 v
I know that the slot designated for one cell usage makes contact because I have run the light using just one cell although at reduced output. Does anyone have any idea what is going on?
Since the battery configuration is not 3S or 2S+1P, a wild guess would be while the 3 batteries are present it will drain the two in series first then the “emergency” slot battery.
Yup, if you look up the reviews, that’s exactly how it was designed… it will deplete the first two cells first, and then operate on the third cell at a diminished output. This is why I decided not to buy this light.
I like to marry the cells to the light, but in this case it would appear to be impossible. I’m thinking that every time I use the light, I will have to discharge the one cell to match the others. Is this correct?
Actually since the third slot is not connected to the main two they can be discharged at different levels, you might end up with different cell wear after time but nothing really harmful to the batteries. The downside is that you will have to carry the weight of two empty cells inside the light when it is running on the backup.
Wonder if some people decide to put the three asymmetrically depleted cells in a different 3P or 3S light thinking the three cells are at the same voltage… :person_facepalming:
I’m new and am still have lots to learn…so pardon me if this seems like a really basic question or if I’m not understanding correctly. I own a G35 and I too have cells dedicated/married to this light. Forget for a moment any dislike for the configuration of the cells…from solely a “battery safety” perspective…it would seem to me that using the light doesn’t bring potential for problems, but rather the charging of cells after using the light?
I expect that this light will get moderate use (maybe 12-15 charge cycles) over a year’s time. It seems to me, that as long as I discharge “emergency cell” to equal the others and then charge them equally…I’ll be well within the safety zone and not too far from proper care for the 3-5 years I expect the cells to be in service. Yes/No??
This is my guess. I don’t think you need to discharge the third cell at all; that would be just time consuming. Just charge all three at the same time. One cell should be fully charged much faster than the other two. If you put the third cell in the same “spare cell” part of the light, then the other two cells will wear faster over time compared to the third cell. However, you’re only charging about 12-15 times a year, so even after 10 years, you should not measure too much wear. The trick is not to put the third cell in the same place in the light, but alternate positions. This way all cells will wear evenly. I think this makes sense.
Edit:
I think problems will arise if you put the 3 cells in a different light, or if you change positions of the cells inside the light when the two cells are almost depleted and the third is full. What will happen is that the third full cell will be in series with the almost empty cell, so low voltage protection will most likely not kick in. Then one of the cells could be discharged below 2.5V, which you don’t want. At least I think this is what would happen.
This does make sense. Thank you. I did give thought to marking and rotating the cells also, but wondered if I was just splitting hairs with the moderate use this light is likely to see. Rotating cells loses a few less points on the convenience meter than does discharging the orphan cell.
I’m still pleased with the light so far and have no regrets.
than does discharging the orphan cell.