…Not only exceeding rated mAh significantly, but landing on a nice even number! This gave me a kick.
I keep this battery in my daughter’s bedside D4V2 with aux always on. Pretty sure it could run for months.
These F38’s aren’t expensive for the capacity and are widely available. Between these and my collection of Molicel P28A’s I feel like I am well covered for unprotected 18650’s.
I’ve heard these are better than the 4000mAh Vapcell N40’s. Anyone know why? Both are rated at 10A CDR.
by Installed64
![[NMD] Shuolide SLD-12C with 12x FFL707A 4000k/5000k mix](https://www.edctips.com/wp-content/uploads/2024/10/3vhpw2lwkosd1-770x515.jpg "[NMD] Shuolide SLD-12C with 12x FFL707A 4000k/5000k mix")
3 Comments
They land a higher mah than the n40’s lol. They are an absolutely amazing cell
[Read the responses/discussion in this thread, ](https://www.reddit.com/r/batteries/comments/1f12krk/stated_capacity_of_this_aa_eneloop_is_1900mah_yet/)as I believe it explains why the charger is indicating that it is exceeding the battery’s charging capacity.
I had the same thing happen with an Eneloop battery (granted, that’s NiMH, but I believe the same thing is happening here)–*i.e.*, my XTAR charger said it added 2,596mAh when my battery was only rated for 1,900mAh. I asked over on r/batteries why the charger would indicate that the battery is being charged beyond its stated capacity. Check out the comment responses, [particularly this one from](https://www.reddit.com/r/batteries/comments/1f12krk/comment/lkdmosx/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button) from u/plasmaticD, who submitted my thread to the official u/XTARofficial account and received the following response back:
>”Thanks for your kind comments. I noticed the customer used Charge mode for this 1900mAh AA Eneloop battery, and the charger showed 2596mAh on the screen. Actually, the capacity statistics of VC4 PLUS charging include the capacity charged into the battery and the capacity lost during charging. As a comment below,”if your resistance increases faster than the capacity decreases, you will get “more” capacity for an older battery than a new one – when measuring charge capacity.” Those extra 696mAh was probably converted to heat. If this AA Eneloop battery internal resistance is high and the battery is old. Then this may happen. And battery capacity is measured correctly when discharging. So if users need to test batteries’ capacity, it’s suggested to use “Grad mode” on xtar chargers. Best Wishes,Hailey”
> these are better than the 4000mah vapcell N40s. anyone know why?
Lower Internal Resistance(about 10%)/less voltage sag under load. According to Mooch’s testing, F38 was the longest-running 18650 at 5A continuous discharge.
That said, it is not that big of a difference and F38/N40 is not meant for Hotrod anyway. Realistically your light will be drawing much less than 5A once the thermal regulation kicks in. So most likely N40 is still a better choice for a passively cooled single 18650 light.
I personally buy F38 due to the above reasons + my usage patterns(mostly burst of 100%, but sometimes hours of 20%ish steady output needed). And F38 at least to me is considerably cheaper than the N40.