Run-Time Plot - UBH-P91 3x123

[Roy]

This runtime plot is for a Universal Battery Holder (UBH) with a P91 bulb and 3x123 Surefire Li batteries.

Equipment used is a photocell and a Radio Shack 22-805 multimeter with a PC interface that is using ScopeView software (V 1.08).

The vertical axis in ma and horizontal axis is 10 minutes per division.

Be aware that your actual battery milage may vary from than indicated by the runtime plot.

After about six minutes the batteries shut down. The UBH was too hot to touch, so I would guess the batteries quit due to thermal overload.

 

[Roy]

 

[Josh]

Looks really nice with the C2 bezel /ubbthreads/images/graemlins/thumbsup.gif

 

[MR Bulk]

Roy, if the battery tube is brass, that could be why. It sucks the heat away, but then hangs onto it. Thermal dissipation into free air is minimal...

 

[this_is_nascar]

[ QUOTE ]
Roy, if the battery tube is brass, that could be why. It sucks the heat away, but then hangs onto it. Thermal dissipation into free air is minimal...

[/ QUOTE ]

The aluminum version fails the same way in 8-10 minutes.

 

[MR Bulk]

Wha...? Then why not the SF bodies themselves?

 

[this_is_nascar]

[ QUOTE ]
MR Bulk said:
Wha...? Then why not the SF bodies themselves?

[/ QUOTE ]

Maybe due to the wall thickness of the SF tubes. They are much thicker or at least feel like they are anyway.

 

[Roy]

Has anyone ACTUALLY done a runtime plot with a 3x123 SureFire flashlight with a P91? The 20 minute runtime figure comes from SureFire spec sheets and I have no reason to believe that SF's numbers are anymore beliveable than any other manufacturers' spec sheets.

 

[this_is_nascar]

[ QUOTE ]
Roy said:
Has anyone ACTUALLY done a runtime plot with a 3x123 SureFire flashlight with a P91? The 20 minute runtime figure comes from SureFire spec sheets and I have no reason to believe that SF's numbers are anymore beliveable than any other manufacturers' spec sheets.

[/ QUOTE ]

Yep. Runs fine for ~12 to 15 minutes.

 

[MR Bulk]

Hey Nascar,

And then what? Thermal shutdown, or battery juice shutdown?

 

[this_is_nascar]

With P91 with the stock SF configuration, it suffers just the normal "ain't enough juice left in the cells" as opposed to the thermal shutdown with the UBH.

The stock P91/SF config yeilds 12-15 minutes, whereas the UBH configuration just goes from really bright to off (the thermal shutdown of the cells) at the 8-10 minute timeframe. I tried this test twice with consistancy.

 

[Brock]

I did a runtime test on them a while ago, but just to compare batteries not an actual run time. Sanyo’s shut down due to heat, but Duracell Ultras ran just under 20 min. They didn't make the SF123 at the time.

I would guess the reason is the amount of metal to use as a heat sink in to in the SF lights. I would suspect that is why SF isn't making an HOLA for the E2, it would go in to thermal shutdown or literally be too hot to handle, not enough metal.