Series, Parallel, and angle

[gcbryan]

OK, I have a two questions that I'm not quite sure of.

The XP-G has an output angle of 125 degrees and the XR-E has a angle of 90 degrees. Which will produce the narrowest angle using a reflector?

1.) Is it the XR-E because it has the narrowest angle or is it the XP-G because it has the widest angle and therefore wouldn't more light make it onto the face of the reflector and produce a narrower beam?

2.) Regarding a quad package (MC-E). Is the light output the same whether wired either 2S2P and driven at 7.2V and 1400mA or 4P and driven at 3.6V and 2800mA or 4S and driven at 14.4V and 700mA?

I've never been quite clear or certain about those two points.

By the way, wouldn't 3 XP-G R5 bin * (2) 18650 be the ultimate hand held light? Burn time could still be close to 2 hours especially with a 50% setting to go to as needed to make that time. This would be 1041 lumens (not OTF of course). Even if you kept it at 50% much of the time look at how efficient it would be and you would still have 500 lumens.

 

[gav6280]

I've never been quite clear or certain about those two points.

By the way, wouldn't 3 XP-G R5 bin * (2) 18650 be the ultimate hand held light?

No 4 would.......:laughing:

 

[znomit]

OK, I have a two questions that I'm not quite sure of.

The XP-G has an output angle of 125 degrees and the XR-E has a angle of 90 degrees. Which will produce the narrowest angle using a reflector?

1.) Is it the XR-E because it has the narrowest angle or is it the XP-G because it has the widest angle and therefore wouldn't more light make it onto the face of the reflector and produce a narrower beam?

2.) Regarding a quad package (MC-E). Is the light output the same whether wired either 2S2P and driven at 7.2V and 1400mA or 4P and driven at 3.6V and 2800mA or 4S and driven at 14.4V and 700mA?

I've never been quite clear or certain about those two points.

By the way, wouldn't 3 XP-G R5 bin * (2) 18650 be the ultimate hand held light? Burn time could still be close to 2 hours especially with a 50% setting to go to as needed to make that time. This would be 1041 lumens (not OTF of course). Even if you kept it at 50% much of the time look at how efficient it would be and you would still have 500 lumens.

1)The wider angle means more light is caught by the reflector and hence better throw for the XPG.
BUT the smaller die size on the XRE means it will throw better.
So the answer is the XPE has better throw than both, especially if you're willing to abuse them and run them at 1A. You weren't planning on getting 50,000hrs out of your dive light were you?

2)As long as each die is getting 700mA it doesn't matter how its delivered.

3)More LEDs is always better

 

[gcbryan]

Thanks Znomit!

 

[Z-Max]

2.) Regarding a quad package (MC-E). Is the light output the same whether wired either 2S2P and driven at 7.2V and 1400mA or 4P and driven at 3.6V and 2800mA or 4S and driven at 14.4V and 700mA?

.

2 18650 ior more? If 2 then 2S2P not intersting because part of worktime you need buckdriver and part of time yo need boost driver.
Driver efficiency the is more than Vin near Vf.

What battery you are going to use?

 

[gcbryan]

My question in one sense was theoretical as I wanted to make sure I understood how this works.

In fact I have a MC-E wired (I believe 2S2P) using (2) 18650's.

I'm not sure what you are asking when you ask what battery I'm going to use? What brand? I'm using 2500mA Trustfires.

2 18650 ior more? If 2 then 2S2P not intersting because part of worktime you need buckdriver and part of time yo need boost driver.
Driver efficiency the is more than Vin near Vf.

What battery you are going to use?

 

[Z-Max]

For 2S2P you need forward voltage 6.8-7 V.
In fresh 2x18650 has 8.4 V (need stepdown driver)
Min.voltage of battery 2x18650 is 5.5 V (step up driver).

As for me, 2s2p excelent choice if you have pack 3x18650.
For 2x18650 I would choose 4P (with step down driver) or 4S (for step up driver).

(sorry for my english )

 

[Packhorse]

I have built a couple of W200's with MC-E's wired 2P2S off two serial 18650's running thought 2 (or 1 3 or 4) AMC7135 chips.
It works really really well!
MC-E's generally have a low Vf so they will run at full output for most of the run time.
I get over 3 hours continuous.

 

[gcbryan]

I thought I read that even though the nominal value of a 18650 is 4.2V as soon as a load is applied it rapidly goes to the 3.7V range.