High drain vs. High capacity?

[uriel250]

@Kos70

Но я дочитал эту ветку до конца, и понял из нее, что не все так просто. Хотя с одним я согласен, чем-то все же приходится жертвовать.

I trust the manufacturer’s data more:

https://batteryservice.bg/wp-content/uploads/2018/12/INR21700-50E.pdf

The datasheet you sent is for Samsung 50E which is a different cell.

[Kos70]

Yes, I'm sorry. Well, find it yourself, it's not difficult ...

[uriel250]

@Kos70

Yes, I’m sorry. Well, find it yourself, it’s not difficult …

Capacity ≥ 2,940mAh @ after 250cycles(60% of the standard capacity)

- Charge : 6A, 4.20V, CCCV 100mA cut-off

• Discharge: 25A , 2.5V cut-off

② Capacity ≥ 2,940mAh @ after 100cycles(60% of the standard capacity)

- Charge : 6A, 4.20V, CCCV 100mA cut-off

• Discharge: 45A, 2.5V cut-off
  (80℃ cut-off, re-discharge release < 50℃)

This is from the manufacturer datasheet, pretty much as stated in the review I sent previously.

[zoulas]

If you are gonna have just one battery, it would be hard to beat the Panasonic GA’s. Like many, this was my first battery. This will work in most lights with the exception of the big gun lights.

[uriel250]

@zoulas

If you are gonna have just one battery, it would be hard to beat the Panasonic GA’s. Like many, this was my first battery. This will work in most lights with the exception of the big gun lights.

I just ordered the Lishen LR2170SD (Sofirn 5000mAh) because I ordered other stuff with it so it is eligible for free shipping.

I will probably buy more cells down the line along with new flashlights from nkon.nl but it will cost me 30$ in shipping, so I need to make quite a big order to justify the expensive shipping costs.

Thanks everyone for the help!

[Jerommel]

@uriel250

@Jerommel

That Convoy has that Osram LED that can only handle 6 Amperes or so (it may handle higher currents but it won’t add much output, plus Convoy always uses current limited (constant current) drivers), so i’d go for a 10 Ampere max discharge current cell for that light.
Some high capacity (>4600mAh) 21700 cells are rated for 9+ Amperes, but that will suffice too.

The Samsung INR21700-50E 4900mAh - 9.8A is what i would look for.

My M21E has SFT40 if that matters, but I still believe it will not exceed 10A.

You’d have to find out what the maximum current is that the driver provides to the SFT40.
My guess is 7 Amperes but could be 6.

[Chicken_Drumstick]

@jon_slider

I vote No High Drain, Yes High Capacity

High Drain only has a brief advantage on Turbo output.

I don’t think that is 100% correct.

Take these two batteries at 3amp (not really Turbo these days). The high drain battery performs much better.

It’s only when the battery is mostly flat that the higher capacity has any advantage, but it won’t be putting out the full brightness either. It’ll just be dim for longer…

Even at 1 amp draw the higher capacity has very little total advantage. It’s really sub 1 amp draw rates that you’ll see meaningful longer runtimes.

[Chicken_Drumstick]

@SIGShooter

@uriel250

@jon_slider

I vote No High Drain, Yes High Capacity

High Drain only has a brief advantage on Turbo output.

I am not a Turbo user. It drains the battery faster, produces excess heat, steps down quickly, exposes my eyes to extra bright light, that constricts my pupils and makes me less adapted to lower output.

I am more interested in the 25% longer runtime at sustainable medium outputs from a High Capacity cell.

The thing is that the 10A discharge rate from the higher capacity battery seems to be more than enough for 99% of the flashlights? Or am I wrong?

I don’t really notice much difference on turbo or even high between high drain or high capacity batteries unless I’m doing a side-by-side comparison. Even then I have to look hard to see any difference at all. Even laptop pulls give me enough brightness for my lights.

I always go with higher capacity given equal prices.

It depends on the light and the batteries, but it can make a huge difference in terms of outputs. Also how long you can sustain high outputs can be markedly different.

[Boaz]

When is the last time you charged a cell 250 times ?

[uriel250]

@Boaz

When is the last time you charged a cell 250 times ?

It’s not about that but the much smaller capacity, at 100 cycles the 4000mAh is roughly 3000mAh, that’s 40% less runtime compared to 5000mAh cell.

[Kos70]

Yes. It will, but only when you operate with those charge and discharge currents that are shown in your link. That is: never...

[SMOKEU]

I wouldn't run my Mateminco PD90S (SFH55 LED with FET driver) on turbo with anything other than a high drain cell. I run mine on either 30T or P42A. Using a low drain cell would significantly reduce the output.

Doing tailcap readings, a 30T gives about 3A more than the P42A. The difference would be much, much bigger if I used a low drain cell, like an NCR21700 (5Ah, 15A).