This post will be lengthy and I apologize in advance.
I have read time and time again how it's better to only partially discharge a Li-Ion cell before recharging it. It's better for cell life. I cannot seem to find advice on this regarding Eneloops no matter how much I search. In short, what I want to know is, would it be harder on the Eneloop to discharge it waaay down then recharge it, or discharge it half way and charge it twice as many times?
To be more clear, let me give an imperfect example: 2 cells have a 2000 mAh capacity. Cell 1 is used and drained to 0, then recharged 100 times. Cell 2 is used and drained to 1000 mAh, then recharged 200 times. At the end, which cell would have a higher capacity remaining? I'm guessing the cell that was only half drained and charged twice as many times would be in better shape, but I can't find opinions in other threads to support this. These Eneloops are listed at 1500 cycles, but surely the cycle count has to be affected by the "depth of cycle"
I know Eneloop reversal is bad, so for the sake of the question, lets rule that out. Lets focus on single cell lights here (like the Zebralight EDC and H series lights)
I sometimes find it hard to gauge when to swap cells. This is especially true on my single cell AA lights. If I use it in 5 minute bursts, some on high, some on high 2 (which has double the run-time) and several times on lower settings, I lose track of how much juice is left. I might grab it out of my pocket, go for high, only to realize all I have left is medium and low. Is this hard on my cell or is this getting the most out of my cell? Is 1500 cycles 1500 cycles regardless of charge/discharge levels? Surely not, but maybe moreso than I think. Maybe you are better off letting it go at least 85% of the way down before a recharge. That's what I'm reaching to find out here.
Because this has been bothering me and I haven't found enough opinions in past threads I've searched, I'm considering doing a test. Taking maybe 4 new cells evenly matched in capacity, then doing some long term tests (at least 25, maybe 50 or 100 cycles or more) then taking results of capacity. The new capacity may be a gauge of cell life or how these circumstances wear on the cell. I can also look at the initial voltage given on the C9000. I don't really want to do this test. It will be time consuming and equipment consuming. I'd rather just get some of your opinions. Surely if I do this test I will share my results.
Has anyone done a similar test that I'm missing? Can you tell me your opinion on when to recharge cells for best lifespan? I appreciate your thoughts!