PD68 Review: Thorfire S70 - XHP70 Monster

Just did a tail cap reading with my new Basen 26650”s which I bought after the good reports on here about them & am disappointed.
4.20A compared to 5.24A with my KP”s, 4.94A with my Thorfires & 5.01A with my 18650 Efest 3100 mah IMR”s.
Post about the Basens”s, post 34 & 35 Basen 26650 4500mAh Issue ?

Tail cap readings does say a lot but not everything!
It all depends on the type of driver used.
With a good buck driver, if the cells maintain a higher voltage the amp draw will be less. And the other way around, if the voltage sag is bigger (thus the cells have a lower voltage) the amp draw will be higher.

Let say the the driver regulates the current to 4.5A to the led.
4.5A x 6.5V = 29.5W.
With some driver losses (10%) that is 32.76W from the batteries, or 4.20A with a voltage of 7.8V (3.9V per battery)
The driver wants to maintain that 4.5A to the led, so the batteries has to deliver 32.76W.
I my above calculations I took your reading of the Basen’s, the voltage is a guess but that’s ok since this is just an example.
We know the batteries has to deliver 32.76W to the driver to maintain 4.5A to the led.
Lets take your other reading, 5.24A.
32.76W / 5.24A = 6.25 / 2 = 3.125V (per battery)
So your KP’s voltage does sag a lot more under load so the driver has to pull more amps to compensate that and maintain 4.5A to the led.
(assuming the Amps to the led are all the same)

If the above is true, it means that the Basen’s are very good batteries, even better then the Efest 3100 mah IMR’s

Pls correct me where i’m wrong, this is how I understand the workings of a buck driver.
I could be wrong, but then I wouldn’t know :laughing: .

Could you make a comparison of luxes, with this different batteries? if you do not have a lux meter, you can use your Smartphone with an App of luxometer. It’s not about getting accurate lux values. It is to see the difference between the batteries.

the Driver in the SD75 i reviewed lately does the same…
(8,4 V input vs. 6v LED)

review: Lumintop SD75 - YouTube <- this Link jumps to the driver test

i think you can understand how a buck driver works

What I am disappointed about isn”t the performance of the Basen”s compared to my other 26650 cells but their performance compared to the earlier Basen 26650 cells.
I know that they have less sag compared to say the KP”s but mine are lower resting voltage, lower capacity & give lower tail cap amps than the earlier Basen”s.
Or am I getting this wrong & the fact that these new Basen”s give lower amp readings than the earlier version actually means they are better ?

Could you make a comparison of luxes, with this different batteries? if you do not have a lux meter, you can use your Smartphone with an App of luxometer. It’s not about getting accurate lux values. It is to see the difference between the batteries.

147,055 with KP”s & Basen”s ?

Exactly the same with both batteries? lol

I don´t understand, same output but Basen 4.2A and KP 5.24A.

That is with a light meter app on my phone.
I have no idea whether the app is any good though ?
Guessing the app isn”t up to much as I just got exactly the same reading using a Thorfire C8s as well ?

Are you guys really in write only mode? Check the video a couple of post before… Buck driver pulls what the led needs. If the voltage sags the amp will be higher, if voltage does not drop under load the amps will be less.

My english is very bad, can you simplify? Are you saying that although the amperage reading is less with Basen, It does not have to give less light?

I guess that is the maximum that can be measured from the lightmeter of your phone. In that case you should be test more distance from the phone.

Yes I know I will phrase my question differently.
This is my question.
2 cells, one weighs 100g, has over 4500mah, resting voltage of 4.18v. & gives a tail cap reading of 5.4A
The other cell weighs under 90g, has just over 4000mah, resting voltage of 4.15v & gives a tail cap reading of 4.2A.
Which is the better cell ?
Is it the 4.2A cell as it is giving more voltage hence the lower tail cap reading ?
The second cell is advertised by the manufacturer as an improvement on the first cell.

Yes. Check my post .
It al has to do with power (watt), amperage only isn’t saying a lot.

We can’t say for sure based on your measurements, it takes a lot more testing to know what battery is better. Though I think that the lower weight cells has a lower internal resistance so you can draw more amps while maintaining a higher voltage. That doesn’t mean it’s better, it’s just capable of delivering higher amps. While the other has a slightly higher capacity.

With the solder pad’s bridged and springs bypassed.

Efest 26650 purple 3500mah on turbo - 8amps at the tailcap.

MNKE 26650 3500mah on turbo - 6.5amps at the tailcap.

Measured with thick short wire and a Brymen multimeter.

I’ve lost interest with my smaller light’s.

Steve Martin once did a skit about being an audiophile. Starting with a little AM transistor radio and moving up to FM Stereo, you want more and more and more, soon enough you have a 10,000Watt system and have to go to the Moon for best hearing experience.

The more lumens we get, the more we want. It’s an never-ending avalanche of incoming lights. Pocket book forewarned.

There’s no doubt about that. :wink:

(N.B. a few swears)

Hi all,

does anybody know which exact type/bin of the XHP-70 is used in the Thorfire S70? I´ve heard there are different ones, N4 or P2…

Also, I´m curious if a simple spring bypass without the “solder blob” driver mod would also slightly bump the amps of this light?
I´d want a little more “juice” from my S70 but I don´t want 8 or 9 amps, I´d like the light to be still practicable, not a pure “show off” light. I don´t want to shave the LED since I really like the floody beam.

Thanks,
K.

The bin isn’t specified anywhere but it’s a cool white.

Doing both spring bypasses will increase the current a little, bridging the solder pad’s will obviously increase it much more.

I did all on mine and I’m getting:

Efest 26650 purple 3500mah on turbo – 8amps at the tailcap.

MNKE 26650 3500mah on turbo – 6.5amps at the tailcap.

So it’s not just about the bypasses and solder blob, you can actually choose the battery type to vary the amount of current that’ll be drawn.

Even with my light drawing 8amps on Turbo you obviously have low, med, high and turbo so I just switch it to medium to conserve the battery and now and then switch to Turbo and then back again to medium.