The thread is Diversified. Original topic is P45B and where to get it.
The test of my K1 involve all three batteries listed. …P42A,P45B and 50S.
The P42A is listed and tested in my K1.See Screenshot.
it’s the very first battery. He says, AFTER the “Full mods” and then P42A. It is the first line in the screenshot.
Tom E. Modded it. Tom E. Measured it.
Not me. I don’t have that skill.
OK… so the results have nothing to specifically with the P45B ?
Just clarifying… as that was what we started discussing here.
I think if you put that light in a Measuring Device ( sphere/tube ) you would be amazed how fast your modified light output drops
I’m with your boy Jon on this one and what he’s saying about the P45Bs
I’d be willing to bet – Tom E tested the amp draw when the cells were full — They don’t stay at that output unless it’s a regulated driver or a serious battery pack
This I do know for Sure.
I use HIGH DRAINS that are best suited for me.
I am far from an expert regarding Electronics of flashlights and exactly how a battery functions. I know the basics and what my preferences are.
When outside on the hiking trails I like Max output until battery depletion.
I do know that when you have a 5,000 Lumen light I’m not going to notice a difference of 200 or 300 lumens. These technical experts proved that about the human eye. Don’t ask me to explain I can not.
-The most important thing to me is a combination of good output and the best run time while not sacrificing run time for a few hundred extra lumens.
When a light(K1) ONLY has 10 minutes of max output it is more important to me to have a minute or two more runtime(50S) than an extra 200/300 lumens?(P45A?)
To me there’s a big difference of an ending voltage(battery change)of 3.58 volts(50S) versus 3.49 volts(P45A).
-I think it’s fair to say that the battery with the lower voltage night after night after night is not going to last as long, in terms of his overall life.
In order to benefit most of you guys, that’s all I can think of for now.
It sounds like you should try out a light with a good regulated output so that you’ll have the same lumens throughout your whole hike (no matter the battery voltage).
Did the P45Bs have less runtime than the 50s — Are you going by when the light steps out of Turbo
The 50s might be a better fit for that light ----- Shoot, I use Pany Bs in some of my direct drives-- Less Turbo output , but longer runtime at a better average Lumens before I burn my hand
Of course he tested them when they were full. That’s how all the tests are done. Turn on 30 seconds . ANSI . He measured them at 0 /10/15 and 30 sec.
Look at the screenshot he has the starting voltage of the batteries. Any of these batteries we’ve talked about on here are going to drop. Some are just better than others. He mentions how the P42A will catch up with the 40t. Not in that screenshot but we exchanged like 180 messages from the beginning when I asked him to help me until he was done.
I’m taking a wild guess just by visual after 5 minutes, the K1 is probably more like 4300/4500 lumens.instead of 5,800. By the time it gets to 10 minutes it’s probably 3500 lumens. That is incremental obviously. Even in the winter I can’t run it for more than 5 minutes at a time. In the summer it’s like 2 minutes let it cool off 3 minutes so battery is going to last me a lot longer.
So I think what we’re seeing here is totally expected behavior from the cell. FET driver, full open. The 45 can deliver more current and be happy doing it compared to the slightly less capable 42, right. Remember that the bench tests are done using constant current, so when you see the graph lines for 10A and 20A, the cell is being drawn consistently at those levels and we’re recording the behavior.
If the FET allows a more capable cell to give 25A in a light than a cell that starts feeling stressed and maxes it at 20A, then yes, you’ll see reduced capacity/run time from the 25A cell. If the driver were regulated to stop at 20A then the better cell would have some headroom and reserve and certainly run longer. With the reduced voltage sag at all currents, as the truth-telling bench tests do show, then the P45B is actually a better cell, no question. Whether that applies to every use case just depends on all the other electrical parameters like the driver and the emitter(s).
Here’s a case where in real use a full open give-it-all-she’s-got FET driver is allowing a “better” cell to go full monty and do it’s thing, but in doing so it’s predictably using up its juice a little faster.
Well said @Correllux, that makes perfect sense to me. The P45B does indeed appear to be the more capable cell!! It just may, for whatever reason; not appeal to some individuals or meet their specefic need.
Yes…50S has slightly better run times than the P45B.Yes, for me 50S is a better fit.
No, not when the light steps down from Turbo… There is no step down for this light. Like most of my lights, depending on the driver , the step down is disabled or the thermal ceiling is set at Max. The light gradually loses output from the moment I turn it on until the voltage is too low for my liking. Then I replace the battery.
This output loss is not noticeable until about minute 7 to minute 10 of Cumulative max (output is lowered a few times to cool it off )where battery is replaced.
For me the 50S are better for indications that I’ve mentioned it’s this post and others. The only negative of the 50s, like mooch stated, is it does get much hotter than the P42A and P45B.
No worries about that, over the years my right index finger and part of my right middle finger have nerve damage and has slight loss of feeling because of all the Heat. 
When I put the light in my left hand it feels so much hotter because of that.
I do not doubt all this technical stuff that has been mentioned.
It’s simple, for me my battery preference and reasons for that have been mentioned several times throughout my posts.
I forgot something.
I know one thing for sure, I don’t need to purchase any flavor of 21700 batteries for a long time.
I have 14 Brand new in storage.
4X P42A, 4 X 40T, 4 X 50S and 2 X P45B.
I don’t like having that many new batteries in storage. I returned a light about 6 months ago and that’s when they started to accumulate.
I bought the batteries for that light. It only took two! But I wanted four, and then bought four more because they were on sale.
Most will be used for single cell lights.
Only Three of them will be for my WT90 when those batteries are worn. I’m guessing it’ll be 3 or 4 years before they are all in use and hopefully six or seven before they’re in the recycle bin.
I just got my P45B Cells today. Very fast shipping. Nice.
Charge them to 3.82 volts are as close to it you can get – They’ll hold up for years — I have some cells 6-8 yrs old and they’re barely degraded – there’s a switch in the Opus to terminate lower ( I think)
Time to get some from Liion wholesale to see how they compare to the Epoch “P45B” batteries I have in my NS73V2.
Also, in unregulated lights, a cell with higher internal resistance will almost always “last longer”, because less light is coming out overall, especially if it has higher capacity.
So runtimes with a 50S in 1st, P42A in 2nd, and P45B in 3rd makes logical sense in an unregulated light, because the 50S has higher resistance AND capacity, the P42 has higher resistance, and the P45B has significantly lower resistance such that having 300 extra mah isn’t enough for it to “last longer”.
You can very easily measure if a certain battery is brighter in an unregulated light by using a simple light meter app with any smartphone, put phone on floor in dark room, shine light at ceiling, take measurement done.
If you want accurate runtime tests to compare results between batteries, ALWAYS use regulated lights as it makes the testing much easier, otherwise you have to measure light output over time.
All of mine are stored between 3.55 and 3.60 volts. I would think that’s better than 3.82 volts. Less stress on the battery. That’s what I’ve read and that’s what I’ve been told we’ll see what unfolds!
I’ve stored some for over a year and the voltage was the same as when I discharged them to 3.6 volts.
Some were 0.01/0.02volts lower after 2 years.
Thanks for all the explanations about how these batteries act, unregulated drivers Etc .
I learned that there are variables that will change certain aspects of how a battery acts.
What made me decide to get this battery was part of mooch’s review where he said,“The P45B runs longer at about15amps or higher” I said great, it’s going to have as much run time as my 50s! That wasn’t the case. even though the difference isn’t that much.
I was unaware of how the above mentioned variables can change or alter that statement.
Mooch has responded as usual to two of my personal messages. I just sent him one final question so he can explain the above statement better.
Then the conversation/ new thread can shift to the Murata TRS21700 …5000mAh CDR 40AMPS👌
Now that’s interesting. What’s the secret code? Google gives me nothing and the Murata sites give me nothing.
It’s called trickery! I was seeing how gullible you guys would be.
That’s my dream battery if something like that ever comes out.
Past my bedtime.
… getting up at 4:00 a.m. as usual hitting the trail , the life of luxury!
Rest in peace a better battery is on the way. Can anyone be able to tell the slight differences between a lot of these batteries in real life? Just a minute, I have to go check my Atorch DL24/P. Oops I forgot it’s bluetooth to my phone.