I have spent time researching what are the best/most efficient/safest chargers for 10440s, but have not found any recent/new chargers for them. Earliest I could find (as in posts or comments) are from early 2019. I am still learning, but I have read that ideally it is best to charge 10440s at 0.2 A. One charger that I found is the Opus BT C3100 as it can be set to have a CC at as low as 200mA. There is also the XTAR MC2 2 which can charge at 2 x 0.25 A at the slowest, but that one can not be manually selected. I would like to know if there is something better and more recent for safely and efficiently charging these little guys? Most chargers that I have found charge at 0.5 A at the slowest, which I know is too fast for 10440s and thus not recommended.
I recently looked for the best charger for 10440, 21700, and NiMh. I ended up buying a Nitecore UMS2 as you can manually select the current all the way down to 100mA, and it supports everything I needed.
Discontinued, but the Xtar XP-1 does 250mA and 500mA and NiMH and li-ion, but only up to AA/14500 sizes. I have 4 of them.
Great little chargers.
Chris
Worth noting the Opus BT-C3100 charges and discharges using 2A+ pulses so not ideal for tiny batteries. It can trip sensitive protection circuits even at low selected current. The Gyrfalcon All-44 and All-88 will do 100mA charging. Has very slow termination but mine usually leaves rested cells at exactly 4.20V if that’s your thing. The SkyRC MC3000 will of course go down to 50mA charging but much more expensive.
Your are taking about the nitecore um2 which can go down to 100mA the UMS2 can only go down to 300mA.
I have the UM2.
Here hkj review on the UMS2
Thats odd. I have the UMS2 and it gives the option of going down to 100mA.
Maybe hkj is wrong
My Nitecore UM2 and UMS2 can have a manually-selected charging current of 100mA. In some places, even HKJ reports that the Nitecore UMS2 can have a manually-selected charging current of 100mA. For example,
https://lygte-info.dk/info/roundCellChargerIndex%20UK.html
Perhaps the UMS4 has a minimum manually-selected charging current of 300mA.
Maybe they ungraded the UMS2 as when i looked into it it was only 300mA.
I’m very happy with the UM2.
On YouTube there is a video by “Nitecore Store.” The video was made 5 years ago. At a time of around 2:10, manual-selection of charging current was begun. The display changed rapidly, but I saw “100mA” on the screen of the Nitecore UMS2 for a fraction of a second.
Seeing that this old post has been revived, I’ll say that my Xtar VC8 can go down to 250mA
Just fine for the Vapcell 330mAh 3A 10440s that I’ve got, which are rated for 500mA charging.
Presumably the newer Xtar high-end chargers can do the same (VC8S, VC4SL)
According to the manual the UMS2 can go down to 100mA while the UMS4 can charge lowest 300mA (can confirm for the UMS4)
The VC4SL can be limited to 250mA
Vapcells S4+ can also charge at 250mA, Dlyfull A4 and A4L at 200mA
ISDT C4 EVO can start at 100mA, increase steps of 100mA