Nimh "D"

[camaro09]

Hi all, as I am new to the whole modded light area. I just recently purchased a P7 3D mag and am curious if alkalines would be as bright for the mag as the Nimh 12000mah it calls for? Will the alkalines just have a shorter runtime or will the brightness suffer also? Thanks for the help.

 

[was.lost.but.now.found]

The way I understand it alkaline may be brighter for about the first 5 minutes due to peak voltage, but that is one of the only benefits of alkaline. After that there will be a quick drop in voltage to below the typical NiMH voltage, and the overall life will be shorter as well.

 

[camaro09]

Awesome that helps. I have some tenergy 10000mah Nimh on order and on there way to me.

 

[balou]

Alkalines have a much higher internal resistance than NiMHs, so they might never be as bright. They just can't put out the current necessary (you said a P7 mag, I just guess it's driven at over 2 amps)

 

[gswitter]

The graph I've seen comparing 3x Duracell alkaline D's and 3x Powerex 10,000 mAh NiMH D's direct driving a P7 showed the NiMH set-up was brighter from the get-go, but the alkaline set-up ran longer.

 

[was.lost.but.now.found]

The graph I've seen comparing 3x Duracell alkaline D's and 3x Powerex 10,000 mAh NiMH D's direct driving a P7 showed the NiMH set-up was brighter from the get-go, but the alkaline set-up ran longer.

Can you find that graph? I'd be interested in the comparison throughout the run.

 

[zelda]

A standard 22Ah alkaline Energizer D cell at 1A discharge, drop after a couple off minutes down to ~0.9v(tested on Futaba CDR 5000) At data.energizer.com are some datasheets from energizer.

zelda

 

[was.lost.but.now.found]

A standard 22Ah alkaline Energizer D cell at 1A discharge, drop after a couple off minutes down to ~0.9v(tested on Futaba CDR 5000) At data.energizer.com are some datasheets from energizer.

zelda

Based off the Energizer data, I don't think you can state their D cell alkaline is rated at 22Ah. Should not standard discharge be at .05C? Looking at the graph for capacity of 22Ah the discharge is .001C. A .05C standard would be more like a 500 mA discharge, 10Ah, and it gets really worse the higher discharge rate you go.