well, just got the tracking number for my light, should arrive next week if all goes well!
Sadly they were not able to add the 21700 cells to the package.
So looks like I am on the hook to get some if I am to see what the real world max performance is. Anyone know of a good deal on 40T cells? I saw some for $5.99, that the best deal around? I know that is cheap for these but dang that adds up quick lol.
I can just use 18650 and swap the cells after a few mins and it should get close to the same thermal output but won’t help with getting peak output numbers. I assume VOB will have some 21700’s to test with though, so could just use his numbers for that. I tend to focus more on the technical side of things, making sure everything is built properly and will survive and last to the best of my ability.
If you really want push max then 30T cells are better but lower runtimes…also the Molicell should be very good if u can find it, Molicel INR21700-P42A 4000mAh - 45A if not 40T are just fine also to use i bet.
Great thanks for the info. I knew about the 30T but figure the difference in output is not worth the difference in runtime according to the discharge graphs I saw.
I had not heard about the Molicel though, I will look into those. Are they really 45A 4000mah?
Molicel is a serious player, right up there with Samsung, Sony, Panasonic, Sanyo and LG. The P42A can do 45A, but it gets really hot. Mooch rates it about 30A continuous. They are not really cheaper or easier to get compared to a 40T. About the same. I doubt Neal could get them.
They were on sale awhile back… I got 10 of them at this $4.99 price… and 8 VTC5A’s for $3.99… shipping was decent like $6.00… it pays to be on their mailing list…
Yes, unprotected, first the protected cells might not fit but mostly this light can pull over 30A, so I don’t think that would play nice with most protection circuits.
The Molicel P42A was reviewed by Mooch and it actually beats the 40T except at the beginning of the discharge curve. However, I think the later revisions of the 40T might have caught up because the recent 40T I bought almost reached 4200mah in my test despite the earlier versions were 4,000mah. Not sure if I just got lucky.
Though I did test a fully charged 40T to output noticeably higher in the Fireflies E07 compared to fully charged P42A. I’m sure the P42A will output higher along the rest of the discharge curve per Mooch’s test but I have no way to test that myself. If you want to get batteries to test max output, 40T is more suitable and capacity is about the same as the P42A, maybe just a bit lower. That’s why I prefer 40T, which is also the most common high power cell, and is likely the cell used by manufacturers in their runtime/output ratings.
Here is my .2 cents (My views aren’t worth 2 cents yet :), get whatever is cheaper. They are both great cells. I have built a few 3v XHP50 FET driven lights and I cannot tell a difference between 40T and P42. If I had a meter I’m sure I could note higher output with the Samsung. If I used a timer, I’m sure I could see better runtime with the Molicel. I don’t really do either and I’ve never noticed the lights pooping out early with the Samsung or being too dim with the Molicel. The top is raised a bit more on the Molicel. I’m not sure if it would be enough to not need to solder blob them though. They are both really good cells.
I can’t tell the difference in output with my eyes. It can only be measured. I think P42A is probably the more practical light because it maintains higher current throughout the discharge but the 40T gives you max output, which most flashaholics are after.
Mooch says the P42A beats the 40T but I think it depends on your usage.
The Molicel P26A 18650 on the other hand kicks serious ass and is easily the best high output cell IMO. I measured a good amount higher output with the P26A than the VTC6 and VTC5D in the E07 and still has decent 2,600mah capacity. The VTC6 and VTC5D outputs higher than the 30Q.