The There Are No Stupid Questions Thread

What is the Voltage rating, current and mAh/Ah rating of that battery pack?
Also what is the output the power brick puts (the charger)?

A Samsung 20R is a common cell used in packs - I found them in current Worx 5 cell 20V packs for example.

Here's the spec sheet: https://cdn.shopify.com/s/files/1/0674/3651/files/INR18650-20R-spec-sheet.pdf?13304021761413850609

High amp chargers are expensive and "rapid chargers" must be high amp. Nitecore chargers in general are cheap, least cheap in terms of highest rated amp charging, they are generally overpriced in the retail market - you pay for the nice packaging, etc.

The 20R normal charge rate is 1 amp (2 hours) while the rapid charge rate is 4 amps (30 mins). The datasheet doesn't get specific about the rapid charge rate effecting the battery's lifetime and performance, least that I could find. Usually it detracts from the overall effective lifetime. Batteries lose capacity and add resistance over time, so all depends how fast or slow the degradation occurs at.

They say in the datasheet:

7.10 Cycle life With standard charge and maximum continuous discharge. Capacity after 250cycles, Capacity ≥ 1,200mAh (60% of the nominal capacity at 25℃)

So, how does it perform using rapid charge? They don't seem to say, but guaranteed it's gonna be worse.

Yes. There are many factors involved, but generally there is a nominal charge rate. On a made up 3000mah battery, let’s say 0.5C and the cell is rated for 400 cycles before its capacity drops to 80% of new. So this 3000mah cell can have a nominal charge rate of 1.5 amp and get 400 cycles (from 2.5v to 4.2v) before it losses 20% of the rated capacity.

Then it might have a maximum charge rate of 1C, 3 amps in this example, and it might only get 250 cycles before it reaches 80% capacity from new.

It may also have a “max cycle life” charge rate of 0.75A. It might give 500 cycles to 80% capacity.

The same goes for discharge. If you subject this 3000mah cell to 10 amp discharges all the time it will loose capacity faster than if you discharge it at 3 amp all the time.

Basically the more stress you put it under charging or discharging the faster the capacity will drop.

With power tools you might see a case where they are optimized for a fast charge. They may have a lower voltage limit of 3.0v and an upper limit of 4.0v. This allows the battery to charge quicker since your only using the constant current phase of li-ion charging. The constant voltage phase at the end from 4.0v to 4.2v is very slow. (I say 4.0v as the transition point, but it can be slightly higher or lower)

So your Bosch is probably using a high drain cell to handle the high charging current and also limiting the max voltage to get that 30 minute recharge time. They may even set the low voltage limit higher to maybe 3.5v. They prioritize the charging speed over cycle life because that is what most people prefer.

Also note that generally smaller capacity cells can recharge faster than high capacity ones.

Nitecore D2 is only 0.5 amp per cell. Very slow.

I use a Miboxer C4-12 that can do 3A x 4. I like to charge fast so I can do other things.

Wait.

You don’t have a NarsilM light to test with? Aren’t you the creator? :stuck_out_tongue:

At work, not home. But I don't program lights/modded lights with NarsilM anymore - use my special version of Anduril now .

I swore at one point I'll never flash firmware again where I can't calibrate voltage and temp from the UI, so now that I modified Anduril to calibrate voltage, and extend temp range, and display a simple version #, I'm pretty happy with it as a NarsilM replacement.

Wow, that’s like letting your own kids sit at home playing with wrapping paper while you take the neighbor’s kids to the park. :open_mouth:

I didn't even follow the link.

Do I think you're an obvious spammer?

Ewww, they suck! I wouldn’t even let a crack-ho wear one of those shirts. :confounded:

So what’s the deal with OSRAM LED emitters? I’ve seen some growing enthusiasm for them. Looks like at least some models are ideal for throw. Are there any current production flashlights OSRAM emitters worth considering with ?

That’s precisely the case - there are several LEDs that throw significantly better than any other LEDs which understandably causes a lot of enthusiasm.

I can’t help myself…
Lowani under two moons.
Sokath! His eyes uncovered!

And for something completely different.
Lord knows what nether regions yon digit has erstwhile probed.

Thanks for the link! I’m looking forward to seeing how these progress. Are there any production hosts using them with notable success?

Here is a stupid question. ” If a XHP 70.2 led is tested for lumen output here on BLF to 8.5K lumens @ 12v and 8 amps ( not sure if accurate ), Can a big flashlight like the GT check 10.5K lumens ” ??

I am trying to verify a lumen tube for accuracy.
Any help is appreciated. :question:

It all depends on the tube and its calibration. Some people have gotten 8.5K, but it was not with Maukka calibrated reference sources. It is very hard to find the right calibration. Depending on your calibration you can make it whatever output you want.

With my 6 volt Convoy L6 with Lexel FET and P1 bin 5700K xhp70.2 with Aspire 4300mah cells it pulled 19.6 amp / 5500 lumen at 1 second and 18.4 amp / 5250 lumen at 20 seconds. This is out the front which includes losses from the reflector and lens.

With a bigger light like the GT you go from 2 x 26650 to 8 x 18650 so it can pull a bit more amperage due to less voltage sag. Instead of 19 amp it can in theory do 21 or 22 amps. Because the output curve of the 70.2 as nearly maxed out, you only see a tiny bit more of output.

So it’s possible to get more output. Especially between a med size light and a big light. For example if my L6 drew 15A and a GT drew 19A. Then you might see a bigger jump in output.

As far as calibrating a Lumen Tube, you need a proper reference source. Every Led varies in output even with the same bin and you don’t always know the details of how it was measured in the first place.

So based on a Maukka calibration source, your 8.5K and 10.5K are way too high. Even for a raw led.

Thanks for the explanation JasonWW.
I also have Maukka calibrated lights and 3 different lumen tubes. The problem I’m having is with big lights that are reading low in all 3.

For example I tested a MT09R at 29.8 amps in a 6 inch tube calibrated with Maukka calibrated lights it checked 14500 lumens. Should that number be around 22K to 25K ? it will burn paper and it has a TA driver.

My 8 inch lumen tube is calibrated with a MT07S with a xhp 35 HI @ 2700 lumens. It reads 24K lumens on the MT09R but also gives 9800 lumens on another light that should be around 8600 lumens. The 6 inch tube is ok for less than 2K from what I’m seeing. Maybe the various beam patterns is the problem. :weary:

I still think your numbers are low. ~20A in 6V XHP70.2 should be getting close to 7000 lumens, especially on a cold start. There are losses for “OTF lumens” but I wouldn’t expect it to be over 15%

According to who? Why do you think this?

I think most OTF losses are between 25 and 35 percent.

You should ask TA. He tested these same lights so he has a good database.