Enlighten me - Liteflux LF2 vs LF5

[alltracturbo]

I was just talking about the looks, I don't plan on buying the older model. I would prefer the rear button than the twist, but i'm sure I would have been happy with the twisty version if I bought it when they didn't have the rear button.

I think the looks got worse with each newer model. I like a smooth clean looking light in a solid black or bare metal. I'd love a newer version that looked just like the original LF2, but with the rear button.


What happens to your settings when you take the battery out. Is there a limited ammount time the settings will be stored with no battery? I checked the .pdf manual on their website, but didn't see anything mentioned about it.

 

[Runo]

Why does a Li-ion cell with only 750mAh last the same or longer than the 2000mAh NiMH eneloop on every power level under 100%? Shown here: http://www.light-reviews.com/liteflux_lf5xt/

Theoretically the LiIon-Cell has more Wh - 3.7V *7 50mAh = 2.775Wh while eneloop has 1.2V * 2000mAh = 2.4Wh. That the one thing.

But then, as far as I know, the electronics are also more efficient with the LiIon-Cells because the Voltage doesn't have to be uptransformed for the LED to work. So for the same brightness you probably need less power [W].

Jojo

PS: Please correct me if someone with better technical knowledge is around

 

[Flying Turtle]

What happens to your settings when you take the battery out. Is there a limited ammount time the settings will be stored with no battery? I checked the .pdf manual on their website, but didn't see anything mentioned about it.

I've never lost my settings during a battery change with the LF2XT. I suppose there could be a time-out, but I'm not sure. I think this came up a long time ago and I'm inclined to say, no, settings are not lost.

Geoff

 

[BabyDoc]

You won't lose the settings, no matter how long the batteries are left out.

 

[alltracturbo]

So for the same brightness you probably need less power.

I don't think it's the same brightness.

LF5XT
750mAh Lithium-ion at 15% - 582 Lux, runtime 6:06
2000mAh NiMH at 15% - 405 Lux, runtime 5:21

The Li-Ion has 1250 less mAh while putting out 177 more Lux and still lasts 45 minutes longer.

 

[Runo]

I don't think it's the same brightness.

LF5XT
750mAh Lithium-ion at 15% - 582 Lux, runtime 6:06
2000mAh NiMH at 15% - 405 Lux, runtime 5:21

The Li-Ion has 1250 less mAh while putting out 177 more Lux and still lasts 45 minutes longer.

You can't just compare mAh without taking voltage into account. Always compare electric energy [Wh] (or mWh if that suits you better), ergo electric charge [(m)Ah] * voltage [V].

Jojo

PS & Edit: You could only compare the el. charge directly if in case of the eneloops the LED was run @ 1.2V while in case of LiIon it was run @3.7V - but that is definitely not the case.

 

[alltracturbo]

OK, I think i'm understanding a little better. I need to do some research on electricity.

I thought the mAh rating was how much power the battery contained, but I guess thats not right since amps are a rating of current. If I understand correctly, the Li-ion can supply 750mA for an hour at 3.7v and the ammount of power the battery has would be shown in watts. So it would be around .75A x 3.7v = 2.775 watts. And the NiMH would be 2A x 1.2v = 2.4 watts.

If that is correct, than a lithium primary with 2900mAh at 1.5v would have 4.35 watts? That seems like a lot.

 

[HKJ]

OK, I think i'm understanding a little better. I need to do some research on electricity.

I thought the mAh rating was how much power the battery contained, but I guess thats not right since amps are a rating of current. If I understand correctly, the Li-ion can supply 750mA for an hour at 3.7v and the ammount of power the battery has would be shown in watts. So it would be around .75A x 3.7v = 2.775 watts. And the NiMH would be 2A x 1.2v = 2.4 watts.

If that is correct, than a lithium primary with 2900mAh at 1.5v would have 4.35 watts? That seems like a lot.

What you write is mostly correct, but you are mixing power and energy. Power is how much you can get immediate and energy is how much you get in total. A battery might be able to deliverer 20 watt, but only for 15 minutes, because it only contains 5 watt hours (Wh).

Another problem with calculating watt hours, is that the battery voltage will slowly drop while using the battery. Here is an example from my 18650 LiIon comparison, the 3 curves are with different load on the battery.

The AA Lithium battery is rated at about 4Wh (depending on load) according to a curve in the data sheet.

 

[Runo]

Yeah, I only let voltage drop (and the raised initial voltage) out of the equation to not make it more complicated.

But... we seem to be trailing far off topic here, perhaps a new thread would make sense.

Jojo

 

[alltracturbo]

Thanks for the info.

But... we seem to be trailing far off topic here, perhaps a new thread would make sense.

Your right, I said earlier that I wasn't going to talk about the batteries here and I would start another thread if I needed to. I was planning on doing some research and searching the forums for the info I need since i'm sure it's been covered before and then start a new thread if I needed to.

This thread was just to get info on the 2XT vs the 5XT and I think I got all the info I needed and decided on the 2XT (until I can afford them both).

 

[burntoshine]

yeah, i've had them both and prefer the LF2XT.

i ended up selling my LF5XT so i could afford a titanium version of the LF2XT with a tritium vial in the button.

best light ever!

 

[alltracturbo]

I like how the tritium vial looks.

What made you sell the 5XT. just too big? Did you carry it much or did it end up getting left behind b/c of it's size.

Edit: When your showing someone the light and they see how bright it is, they'll ask what type of battery could be that small and power a light that bright. Then you can show them the button and say thats the power source. It's a tritium reactor powered by radioactive hydrogen and it only loses half its power in 12 years.

 

[bansuri]

What made you sell the 5XT. just too big? Did you carry it much or did it end up getting left behind b/c of it's size..

IMHO, too long and too thick.

 

[KuKu427]

When your showing someone the light and they see how bright it is, they'll ask what type of battery could be that small and power a light that bright. Then you can show them the button and say thats the power source. It's a tritium reactor powered by radioactive hydrogen and it only loses half its power in 12 years.

LOL! I have to remember that one the next time I show off my light.

 

[alltracturbo]

Thanks for everyones help. Just placed an order for the LF2XT, XP-G R5 upgrade, Sapphire window, and Li-Ion set.:twothumbs

 

[CNR]

You won't regret it :twothumbs
If you can, do tell us your impressions when you try it

 

[alltracturbo]

I just got the light today and it's great. It's the perfect size and very bright.

I had the stiffer spring installed and after playing with it for about an hour and learning how to program it, it feels like a workout for your thumb. I think this is good though. That way it won't turn on in your pocket by accident.

The compact user interface is very easy to use and the Full function user interface is a little more involved, but not that difficult after you read the instructions.

The only thing that I don't completely understand is the brightness readout. I don't think the instructions are clear enough explaining this part.


Edit: Nevermind about checking the brightness percent, I figured it out. I didn't know you could only check the brightness when you were in the programming mode. I was trying to check it while normally using the light and it was giving me the voltage, thats why I was confused.

I got to use it for the first time at night and it's really bright. I do feel the same way as a lot of people about the lowest brightness, it would be better if it had a lower low for reading.