if sst-50 can handle 5 amp, why do 2800 mah versions exist?

[waddup]

not sure Amps and mahs are even the same thing?

but if they are, and an sst-50 can survive with 5 amp,

why are so many lights only driven to 2800mah?

 

[csshih]

simple. 8 x 7135 driver.

 

[waddup]

simple. 8 x 7135 driver.

errm, doesnt help me much, elaborate a lil please

are you saying a driver exists to drive the sst-50 to 55% so people use it instead of driving it harder with a different driver?

 

[LotusDarkrose]

I think he's saying that the 2800ma ones use a a 8x 7135 regulator board. Since 4x 7135 boards are 1400ma. Please, always correct me if I'm wrong the first chance you get, lol. I needs it when appropriate

 

[mvyrmnd]

A lot of it will come down to heat. If you were to push a SST-50 to 5A in a P60 module, for example, it would be spectacularly bright for about a minute... until it caught fire.

In a small host, under-driving it at 2.8A gives similar brightness to a P7, a smoother beam than a P7 and maybe even less heat than a P7 at 2.8A (i'm theorising on the less heat bit, feel free to correct me on this)

If you want a balls-out 5A SST-50, then you'll need something like a Mag with a britelumens heatsink, or something the size and heft of a Jetbeam RRT-3, purely for heatsinking reasons.

On a side note: mAh is a measurement of battery capacity. mA is a measurement of current. I think in your OP you mean 2800mA (2.8A).

 

[csshih]

errm, doesnt help me much, elaborate a lil please

are you saying a driver exists to drive the sst-50 to 55% so people use it instead of driving it harder with a different driver?

oh! so sorry about that! was posting when I was sorta sleep.

the 7135 chip seems to be one of the most common chips used in medium end lights -- each chip will do 350mA -- so 8 of them will do 2800mA!

don't think any more chips will fit due to heat and size constraints!

 

[flashfiend]

As all the above have mentioned or alluded to, there are no 5 amp drivers that fit in the commonly used P60 format. Now if you jump up to mag sizes you may have a few options.

 

[joe1512]

Some lights push the envelope more than others.

For example, this Lumapower D-mini ultra is very heavily driven for such a small light.
http://www.candlepowerforums.com/vb/showthread.php?t=256647


Another issue besides heat is amperage pull. A 1x18650 battery can only pull so much current. Anything past 4 Amps is pretty hard on the battery unless you use a special "IMR" one that can pull lots of current but has less runtime.

 

[flashfiend]

Another issue besides heat is amperage pull. A 1x18650 battery can only pull so much current. Anything past 4 Amps is pretty hard on the battery unless you use a special "IMR" one that can pull lots of current but has less runtime.

I'm sure you already know but an 18650 2600mAh battery can handle 5.2 amp discharge and the new 2900mAh battery can handle 5.8 amp discharge. Not that its any easier on the cell itself but it is more than safely capable of handling a 5 amp discharge.l

 

[carrot]

the "h" shouldn't be used here. It's 2800mA, or 2.8A, not mAh or Ah.

A and mA is a measure of current, and Ah and mAh is a measure of capacity.

 

[flashfiend]

the "h" shouldn't be used here. It's 2800mA, or 2.8A, not mAh or Ah.

A and mA is a measure of current, and Ah and mAh is a measure of capacity.

Don't know if you might want to clarify that you are referring to the subject head.

 

[waddup]

thanks all, much clearer in my mind now :candle: