A couple of 3S converter measurements

[tino_ale]

Hi all,

Not much but still interesting IMO.

First, starting from 4.3V input voltage and going down :
- In low mode, the output drops at about 2.0V
- In medium mode, the output drops at about 2.1V
- In high mode, the output drops at about 2.0V

Conclusion : the converter is a perfect match to 2AA battery pack.
Regulation will drop around 1V on each cell which is quite perfect to protect Ni-MH from overdischarge. BTW after the converter drops out of regulation, the output drops dramatically every little input voltage drop. On Ni-MH the signal will be pretty clear.

Second, the three levels are as follow (taking high as a reference) :
High : 100%
Medium : 27%
Low : 4%

The more I'm using this converter the more I think it is a perfect, KISS, user friendly converter.

That's it

 

[Codeman]

That's good news for those of us wanting to use 2xAA NiMH in the new pak.

Thanks for the work, sir!

 

[McGizmo]

Hi Tino,
Thanks for the data points. I was warned by the converter designer not to use a bench supply because any voltage spike could damage the controller. It has been less than ideal for me bench testing these Light Engines because I use a primary battery as a power source. I have done some limited bench testing but with caution and knowledge that I could damage the LE being tested.

I was told by the designer via interpreter that the 3S was viable on 2xAA batteries prior to going forward with the 2xAA pak and suggesting its use with the 3s converters. I admit up front that these converters are black boxes to me and I wish I understood them better but danged if I could build any LED flashlights without them!! :bow:

 

[tino_ale]

Smokin the converter would have suck for sure! :sick2:

Wow, looks like I'm a lucky guy, the LE seems to be just fine! haha

My bench supply is a dirty ebay piece of junk but quality bench supply should no produce any spikes even on startup or switch off.

 

[FrogmanM]

Thank you for the info tino_ale!

-Mayo

 

[fyrstormer]

I don't think you can really over-discharge nickel batteries. Last I checked, they actually benefit from being run into the ground every once in a while.

 

[tino_ale]

I don't think you can really over-discharge nickel batteries. Last I checked, they actually benefit from being run into the ground every once in a while.

You can definetely overdischarge Ni-MH cells. If you go under 0.9V, at a low load or for any significant period of time you are not doing them any good to say the least.

Ni-Cd are different animals.

 

[fyrstormer]

Hmm. I didn't think the anode material mattered that much. shows what I know, I guess.