Need advice on how to power my newest mag project.

[Justin Case]

Re: Need advide on how to power my newest mag project.

Option #1, presumably 4S2P. That gives 1200mAh and 14.8V nominal, not 4800mAh. Total energy density is 14.8*1.2 = 17.8Wh.

Option #2, 3Sx26500 gives 2300mAh and 11.1V nominal, not 6900mAh. Total energy density is 11.1*2.3 = 25.5Wh.

Option #3, 4S 14500 cells gives 14.8*0.6 = 8.9Wh.

At full power, an SST-90 draws about 9A * 3.6V = 32.4W. Thus, at best, you might get the following run times:

#1, 17.8/32.4 = 33 min
#2, 25.5/32.4 = 47 min
#3, 8.9/32.4 = 16 min

I would go with #2 if you want a realistic chance of getting 30 min run time.

 

[DKlaser]

Would you not multiply the mah per call by the total amount of cells to get total mah?

I am seriously considering doing option #3. I think that would be cool as all get out... If you guys think I could get a solid 15 minutes of runtime out of it I am seriously considering it. It's either that or option 2. Option 1 is way too expensive and not as good as #2.

 

[Morelite]

Would you not multiply the mah per call by the total amount of cells to get total mah?

Not when used in series, when used in series you add up the voltage while the capacity remains as a single cell and when used in parallel you add up the capacity (mAh) while the voltage remains the same as a single cell.

 

[DKlaser]

Ahh, got it now. I really like the idea more and more of having a 1D stubby :devil: If it was your light and you had to choose between the 2 options of using the 3x IMR26500 cells in a 2D mag and the 1D stubby with 4, IMR14500 cells which way would you lean already having a good utility light that has good output?

EDIT: I just found some IMR 14650 cells that have 950mah. That would bump my run time up a tad...

 

[vestureofblood]

Dk,

This is just MHO, but I'd say at this point go for exactly what you reeeealy want. I have a feeling that if at this point we advised you to go with the 3 26650s in the 2D you would be disappointed.

Besides if you already have a responsible "use" type build why not build the light that makes you excited when you pick it up. After all thats what this hobby is realy about anyway.

I say GO FOR IT!!!

 

[DKlaser]

Sounds like a plan...... I'll keep you guys updated.

 

[Justin Case]

Better check the ID of your D Mag tube. Most likely, you'll need to get it bored to fit four 14xxx sized cells.

 

[DKlaser]

I am aware. I am going to have jesus take care of that when he shortens it to a 1D and finns and flutes the head