P7 1D Mag Output & Temperature Graphs

[Cheesy]

The setup:

DSXPJ P7 on Britelumens heatsink in Britelumens 1D Finned HA Mag with KD smooth reflector & KD unprotected D lithium, pointed at a light meter and temperature measured by DMM with Pt1000 sensor on the body behind the head.



Click for full size if you don't have a magnifying glass handy.

Green trace and left Y axis is output scaled as a percentage of maximum, blue/right is temperature in °C (still air, no cooling).

I'm not sure what the jump in the middle is but may be due to the magnet on the positive terminal shifting and altering resistance. This cell was previously used as the rearmost of a pair and the solder blob has flattened too much to make contact, the front one is OK.


Kev.

 

[Drewfus2101]

I'm assuming direct drive? What is the listed capacity of the battery? 5000 mAh?

 

[Drewfus2101]

Oh and good info. I'm about to do the same build, but with a protected KD D size lithium ion.

 

[Cheesy]

I knew I'd forget something. Yes, DD, there is a JST RCY connector between the switch and the LED for easier disassembly in the future. The LED is mounted with Arctic Alumina epoxy and the HS/body junction uses Arctic Silver 5.

The KD cells are 5Ah but even at 0.2C I don't think they return much over 4Ah, I have two protected cells that I'll try and test.

The resting voltage post test was 3.3V.

I'm glad someone found it useful.


Kev.

 

[Cheesy]

Alright, I won't have time to do a ~5 hour 0.2C discharge until Friday or the weekend so here is a KD protected D cell in the light, conditions as post #1:



Again, click for full size. I assume that with nearly 90 views, someone would tell me if the full size wasn't working?

I did intend to let it run until the protection cut off but I got bored. Alternatively, it may not have worked, the KD website doesn't say what voltage the over discharge cut off is at, the cell was resting at 2.84V afterwards IIRC.

The temperature trace ends early as I failed to anticipate the duration of the run and the DMM memory filled up due to too high a sample rate.


Kev.

 

[Aircraft800]

Great Work Kev!

This will give me an idea where to set the thermal shutoff on the D2Flex Driver. Looks like a nice setup, 1.5 Hr run at roughly 800 Lumen, I'm currently building one for a work light.

Thanks!

 

[Northern Lights]

Great Work Kev!

This will give me an idea where to set the thermal shutoff on the D2Flex Driver. Looks like a nice setup, 1.5 Hr run at roughly 800 Lumen, I'm currently building one for a work light.

Thanks!

Ditto for the D2FLEX, a shot in the dark without your input, thanks.