I have a 3C Mag with a Malkoff XM-L2 drop-in that I plan to take on a trip with me. I’m not too sure how many opportunities I will have to charge batteries. So, all other factors being equal, more capacity is better. And, at least within a certain period of time after charging, 5000mAH Tenergy Premiums would give me significantly more runtime than 4000mAH Tenergy Centuras. Of course, the Premiums will self discharge faster. So my question is this: within what kind of timeframe will HSD batteries self-discharge to the point that they hold the same charge as a LSD batteries? Could it happen within just a couple of days? Or are we talking about weeks or months? In other words, if I can only charge my batteries, say, every couple of days, am I still better off with HSD batteries vs LSD batteries?
too many variables, the internal construction being the biggest and we don’t have that information to work with, so unless someone has done this test with batteries the same age as you would be using (age is another factor) i don’t think we have enough info to give you an informed answer
Unfortunately, all I currently have are LSD batteries. So I can’t do the obvious and do a runtime test without first buying HSD batteries. The only batteries for which I have both HSD and LSD batteries are AAA batteries. Not sure if a runtime comparison would tell me anything here.
I have tested so far some cheap hsds and LSD and after 3 weeks the hsds were less than half full…and the LSD were at about 90% of initial capacity…so I threw almost all of my old HsD I had in the bin. I also got such feedback from a friend who complained that every time he grabs some of his rechargeable batteries these were empty…
But it’s kind of unfair because the HSDs most people have are significantly older than the LSDs
I have no D batteries to test, I am not sure if Ds behave better or bader.
I would say in this particular case that one week is no problem…but I would not go for HSD if I could get LSD with about same capacity.
But I have seen some HSD D cells claimed about 10000Ah… tempting.
Just for info: I bought a pair dura loops last year and they were sitting for years in a cheapo store these had 1150mAh capacity remaining…
Actually, the batteries I will be using are C’s (and not D’s). In either case, I would be using Tenergy batteries. So quality would be the same between the two. And, of course, in my case, the HSD batteries will actually be newer. Also, I’m more concerned about how HSD batteries will perform vs LSD batteries after a few days rather than a few weeks.
Temperature is an issue - if it’s hot, self discharge will be worse - like trebled at 45centigrade. Or so it says here. Nickel–metal hydride battery - Wikipedia
It really is very highly dependent on your usage pattern. I’d use the numbers in the Wiki article to see what’ll work best for you.
At 40C (100F roughly) or above I’d go for the LSDs as normal ones could (But probably won’t) lose 50% in a day.
NiCd of the same capacity might be a better bet.
Or might not.
I have 6 of the Tengery 5000mah ‘C’ cells and they self discharge very slowly.I have left them in flashlights for several months with little aparent self-discharge.It seems that the newer, larger sized ni-mh cells just don’t discharge as quicly as the older Nicad cells.I would stick with the 5000 mah cells.-Rick
Although not a scientific evaluation, I just discharged 4 x 10,000 mAh “D” tenergy cells (not LSD) after sitting fully charged for around 9 months. I observed roughly a 25% self discharge rate… not bad at all. They will be cycled often during the summer months so its not an issue for me. They were stored at 50 degrees F, which probably helped maintain their voltage… I forgot to discharge them for long term storage. :~
I have 60 or so tenergy cells in the c size, half Lsd. Unless you are using the entire battery on day 1 then there is virtually no benefit not buying Lsd. I wouldn’t tell a friend to buy anything else but the centuras.
With NiMH or NiCd they won’t fare any better being discharged for long-term storage.
That’s a lithium thing.
Keep them cool and don’t worry much about charge level. I’ve stored NiFe cells fully charged at 50C (No alternative where I lived then, those cells were the power supply for the school lab I worked in - they got charged by my motorcycle.) and fully discharged at the same temperature. Seemed to make no difference. But these were huge cells, they weighed around 2kg each. They even got stored fully charged until all the electrolyte had evaporated - at least the aqueous bit of it.
But NiFe is tougher than NiCd which is way tougher than NiMH (Which hadn’t been invented then)
Thanks for the tip Don. Mine are all NiMH and I’ll keep that in mind. Ive been rotating all my eneloops in the same way and keeping charged only what I use 30 days out… all the time I wasted there. lol
I’ve had non LSD rayovacs that had 80% charge remaining 6 months later, i’ve had non LSD energizers down to 15% charge (lost 85%) in 2 days so YMMV!
This proves you can’t make generalizations, and there are other factors such as charge method, temp, age of batteries, brand, charge they were stored at, how many cycles they have gone through, how badly they were were abused, how long have they been left empty, manufacturing variations, the odd bad apple battery (i used to usually get one per 4 pack for off brands), and many more factors that all affect rate of self discharge :~
I don’t know if this proves anything. But the other day, I fully charged a set of AAA Duraloops and 1000 mAH Japanese made Duracell AAA HSD batteries. I let them sit for three days. And I tried them in my new Tank 007 E09. The nice thing about this light is that it draws SO much current on high that the dropoff at the end of the charge is both noticeable and rapid. The Duraloops lasted about 25 minutes (plus or minus). And the HSD Duracell 1000s lasted about 30 minutes (also plus or minus). And this was consistent between two cells in each batch. When you do the math and take into account any innaccuracies in the time measurement, it comes out pretty much EXACTLY equal to the ratio of the capacities (1000/800, or 1.25). So at least with these particular batteries and in a time frame of a few days, HSD batteries are the clear winner. It just goes to show you that the all too common mantra of ‘Go LSD or go home’ is NOT always true. And it’s especially not true with smaller batteries, where you are going to burn through batteries in minutes or hours rather than needing a flashlight to be on ‘standby’ for months.
The rule of thumb for standard NiCd’s is about 1% per day loss at room temperature. NiMh will probably be different, and within NiMh there are now all sorts of nuances in the design, construction and materials, so for HSD NiMh cells it could be better or worse than the 1% for NiCd’s. I’ve retired just about all of my HSD NiMh cells and replaced them Eneloop XXX LSD’s, and they definitely hold a usable charge much longer, but I have made no attempt to measure it.
I get more run time from my Philips NiMH which are non-LSD than 3rd gen eneloop AAA in my Tank007 TK-703, but the light is also not as bright on the Philips. Since I was recharging the cells every 24-36 hrs I did not notice the self-discharge.
It would be interesting to repeat with high capacity non-LSD cells, but I find my eneloops are good enough for my needs in this respect.
That’s because the eneloop have a higher voltage during the discharge, that causes more current to flow…brighter light and shorter on time…
So these “how long lights it up until” tests are not a good instrument for measuring capacity or energy…
But they are good for having fun and playing around so everything is fine :bigsmile:
That’s why I hadn’t wrote it done, but since Chloe begun bashing I thought i have to join.
That’s why we should look at hkjs graphs to compare our batteries, higher voltage curve and higher capacity both are needed for an optimal battery.
But higher voltage could also lead to shorter runtime in a non regulated light.
Non-LSD is arguably more exciting. There is always that element of “will my light work or not?” :bigsmile:
Sort of like Flashlight roulette, lol.
Remember, though, that I’m not talking about a flashlight in the drawer that needs to be usable at any time for the next several months. I’m talking about a flashlight that is going to be used for the next several days. For instance, if you’re going camping for a few days and may not be able to recharge, the higher capacity of HSD batteries is probably going to win out over the low self discharge rate of LSD batteries. In that timeframe, it would appear that self discharge ISN’T going to bring available capacity down to that of a fully charged LSD battery. Also, from what I have noticed, the HSD batteries sold today (like my Japanese made Duracell 1000s) seem to be MUCH better than the HSD batteries of yesteryear (like, say, Energizer 2500 AAs) when it comes to holding a charge. Now what I woukd REALLY like to see is how Tenergy Premium C cells compare to the Centuras.
Yes, its day max, but I have only experience with AAs. But you also have to count in much longer usable life of the cells as the HSD degrade faster with constant charging and self-discharging and they also seem to be more robust and durable. I wouldn’t buy anything else than LSD today.