I was looking for a form factor that is easy to hold but provide descent power capacity. The D-cell mag-light is king but due to not being able to get a full grip on it I would drop it 2-3 times a night. Someone mentioned that a C-cell is better for smaller hands and since I have had my C-cell only dropped it twice(when I hit my hand on something). C-cells have been somewhat Impotent so I was looking for a replacement. If they'd come out with a lithium cell the size of 2C-cells and 3.7v like the 18650 with higher mAh that would be ideal.
I have found a solution to my problem for the meantime(it dose waist some space though). Menard's has 3/4" PVC nipple(the12" length will work for 3-4 18650's SKU 38102) that fits 18650's perfectly. The outside has to be sanded down about .5 mm to fit the C-cell mag-light body. Three 18650's fit almost perfectly (2mm shorter) in a 4C mag and would provide 11.1v instead of 4.8v. Also a 5C cell can be used the same way to hold 4 18650's (15mm longer) if you remove the spare lamp and move the spring back to the spare lamp section. this gives you 14.8v (16.2v over-voltage) instead of 6v. with this set up I could almost drive 4 CREE's in series with only current regulation. might have to tweak a board to do this though.
Here is some of my rough calculations just using specs@1A to keep it compairable:
C-cell configurations
(4-cell light)
18650 3.7v@2500mah =9.25WH power density 3(27.75wh)@11.1v (Trustfire)7.5h@1A
C-cell 1.2v@2500mah = 3WH 4(12Wh)@4.8v (energizer)10h@1A
C-cell 1.2v@6000mah = 7.2WH 4(28.8Wh)@4.8v (accupower)24h@1A
(5-cell light)
18650 3.7v@2500mah =9.25WH power density 4(37wh)@14.8v (Trustfire)10h@1A
C-cell 1.2v@2500mah = 3WH 5(15Wh)@6v (energizer)12.5h@1A
C-cell 1.2v@6000mah = 7.2WH 5(36Wh)@6v (accupower)30h@1A
D-cell configuration
(5-cell light)
D-cell 1.2v@11500mah = 13.8Wh 5(69Wh)@6v (accupower)57.5h@1A
(3AA to 1D converter)
3AA@2500mah 3.6v@7500mah = 27Wh 5(135Wh)@18v (energizer)37.5h@1A
3AA@2900mah 3.6v@8700mah = 31.32Wh 5(156.6Wh)@18v (accupower)43.5h@1A
I have found a solution to my problem for the meantime(it dose waist some space though). Menard's has 3/4" PVC nipple(the12" length will work for 3-4 18650's SKU 38102) that fits 18650's perfectly. The outside has to be sanded down about .5 mm to fit the C-cell mag-light body. Three 18650's fit almost perfectly (2mm shorter) in a 4C mag and would provide 11.1v instead of 4.8v. Also a 5C cell can be used the same way to hold 4 18650's (15mm longer) if you remove the spare lamp and move the spring back to the spare lamp section. this gives you 14.8v (16.2v over-voltage) instead of 6v. with this set up I could almost drive 4 CREE's in series with only current regulation. might have to tweak a board to do this though.
Here is some of my rough calculations just using specs@1A to keep it compairable:
C-cell configurations
(4-cell light)
18650 3.7v@2500mah =9.25WH power density 3(27.75wh)@11.1v (Trustfire)7.5h@1A
C-cell 1.2v@2500mah = 3WH 4(12Wh)@4.8v (energizer)10h@1A
C-cell 1.2v@6000mah = 7.2WH 4(28.8Wh)@4.8v (accupower)24h@1A
(5-cell light)
18650 3.7v@2500mah =9.25WH power density 4(37wh)@14.8v (Trustfire)10h@1A
C-cell 1.2v@2500mah = 3WH 5(15Wh)@6v (energizer)12.5h@1A
C-cell 1.2v@6000mah = 7.2WH 5(36Wh)@6v (accupower)30h@1A
D-cell configuration
(5-cell light)
D-cell 1.2v@11500mah = 13.8Wh 5(69Wh)@6v (accupower)57.5h@1A
(3AA to 1D converter)
3AA@2500mah 3.6v@7500mah = 27Wh 5(135Wh)@18v (energizer)37.5h@1A
3AA@2900mah 3.6v@8700mah = 31.32Wh 5(156.6Wh)@18v (accupower)43.5h@1A
