Nitecore UM4 Battery Charger: Review

[@MrBazReviews]

Amazon USA - amzn.to/33downI UK - amzn.to/2IFm0Nv Nitecore Store Amazon - amzn.to/3TmGWf3 Support the channel on Patreon - www.patreon.com/mrbazreviews

[@brycenew]

Another excellent review. Detailed pros and cons is very helpful. I'm very appreciative of what you do and how you do it - thank you!

[@MrBazReviews]

I appreciate that!

[@bernardtan1]

@@MrBazReviews Does the UM4's LCD screen go DIM after 10 minutes of inactivity or no pushing of C & V buttons ?

[@lorandhorvath4466]

I have a Nitecore UMS2 which cooks the Eneloop Pro AA 2500 mAh when charging at 1000 mA (which is a 0.4C charge rate). At the end of the charge, they get quite hot and it takes forever to terminate the charge. Any idea why?

[@MrBazReviews]

I have charged AA at 1.0 amp, but usually I'd go a bit lower 500-700. It should terminate, when it detects the delta V aka the slight drop in voltage once fully charged. There is a bit more heat produced using this than a voltage/top off charge method (Xtar VC4). I've not seen a termination issue on this unit, if you have problems get in touch with the seller/nitecore

[@lorandhorvath4466]

@@MrBazReviews Thanks, I will try the default 500 mA current on Eneloop AA 2000 mAh and 600 mA on Eneloop Pro AA 2500 mAh. That would be about a 0.25C charge rate. It should still terminate, but with less heat when approaching the end of charging...

[@lorandhorvath4466]

@@MrBazReviews Alright, so I did 2 tests on the Eneloop Pro AA 2500 mAh with the Nitecore UMS2 charger: One charged at 1200 mA (~0.5C rate) pushed 2888 mAh in it and got quite hot after it passed the 2700 mAh charged value - not good. The other charged at 600 mA (~0.25C rate) pushed 2738 mAh and only got slightly warm at the end - that's what I was after, since it's well-known that the Eneloop Pro's are very sensitive to high temperatures. The 2 batteries were from the same package and almost new (3 or 4 recharge cycles). So yes, you were right to charge at a lower rate, albeit I had to wait more than 4 1/2 hours at 600 mA, vs 2 1/2 hours at 1200 mA charging current. Another interesting thing to notice, regarding the charge termination concerns, is that the lower rate 600 mA detected the termination point faster (@ 2738 mAh) than the higher rate 1200 mA (@ 2888 mAh - that was too slow, hence the battery getting hot at the end).

[@rondeschanelgarcia4963]

Hi Mr. Baz, what specific Brand of charger did you use in this video, and how many Watts is it rated? I used a QC 3.0 5V-3A 18W charger on my UM4 but it doesn't show the "Quick Charge" display on the LCD screen. Should I get the ones with 40W? I hope you can help me.

[@MrBazReviews]

This is the one used in the video amzn.to/35BbEYS. That one is rated to 39W

[@richard1113]

5:56 You mention something about the "FC4" having higher resolution? Which charger is this? I can't get any good search results.

[@MrBazReviews]

It's the SC4

[@bigfella6629]

Not sure if I missed it but can the UM4 do a charge discharge charge to show full mah battery capacity at all?

[@MrBazReviews]

Not on this one only charge capacity, no discharge test. Nitecore currently don't have a tester/charger, maybe they will in future

[@bigfella6629]

@@MrBazReviews Thanks for reply, I have been watching your vids most of the day, trying to decide on a charger for my 18650 batts. Would like something like the xtar dragon VP4 plus but without the hefty price tag...lol

[@petrvalkoun4539]

thanks for the info and the warning about the higher reported IR values!

[@MrBazReviews]

It's an OK charger apart from that for Li-ion it's not great for AA/AAA as they cells can slip off the contacts. Just needs more spring pressure

[@Studat]

@@MrBazReviews my ir shows poor on a couple of my olights batteries but the voltage is fine.

[@MrBazReviews]

@@Studat Did you watch the video? IR values cannot be trusted

[@Studat]

@@MrBazReviews I watched it and agree. I turned off the charger and turned it back on and it changed to good.

[@Palaryel]

I have an Nitecore i2 for years now and it serves well, however I decided to get a 4 slot charger now and thought of going Nitecore again considering I (nor any of my friends who own them) didnt have any issues with them so far. Particularly UM4 and SC4 caught my attention, however I'm not sure which one of the 2 to go for since they seem quite similar on paper (except that the SC4 costs ~10$ more). Could you please tell me if there is a big difference between the 2 models considering you reviewed both of them and which one would be preferable to get?

[@MrBazReviews]

SC4 is mains higher res screen has higher charging speed, UM4 can charge protected 20/21700's (SC4 cannot unprotected) I think the UM4 is better overall based on that last point bar the IR measurements which seem off. I do like the SC4 screen but that's my take (1.5A charging is fast enough if not then they have a faster version)

[@Palaryel]

@@MrBazReviews So considering I use unprotected baterries 99% of the time and I prefer them being charged faster if needed (mostly use them for vaping) SC should be the better option in my case. Thanks for taking the time to reply :)

[@mouthmw]

@@Palaryel he forgot to mention one big difference as well - SC4 can be plugged into the mains and comes with the standard Nitecore power cable, UM4 only comes with the USB cable.

[@Palaryel]

@@mouthmw I was aware of that at the time of writing. Not a big deal, but I do prefer a normal power line connection. Anyways, I bought the SC4, have it for about 6 weeks now, the device is amazing. I really like how it allows me to charge my 18650s to 4.3V, the extra capacity comes handy at time (I do realize it may impair the overall battery life tho). Anyways I can only recommend the device.

[@mouthmw]

Awesome! Mine is on the way! Mind if I ask you something about it? I'm curious about one thing - I'm only gonna charge 18650 batteries on it (Sony VTC6, VTC5A and LG HG2). Now, I'd like to set the charge rate to 1A, perhaps even around 800mA for LGs. If I change the charge rate setting, does it save that setting if I unplug the charger (I always unplug the charger when it's not in use), or will I have to change the setting every time? Thanks!

[@fiocco10]

Hello, UM4 can recharge Li-ion ICR 19/66 ? thx.

[@MrBazReviews]

That's a battery pack? Only the cells listed on the box can be charged

[@fiocco10]

@@MrBazReviews Solar battery 3,7v 😉

[@MrBazReviews]

@@fiocco10 If it fits it can charge

[@fiocco10]

@@MrBazReviews Li-ion ICR 19/66 - 3.7V/1300mAh = 18650 form factor so i bought UM4 charger and it work perfectly, thank you.

[@MrBikboi]

For quick charge do you just require the wall plug in with QC, will the supplied usb cord suffice for QC with that?

[@MrBazReviews]

Yes QC output cable of course supports QC

[@Orvis25]

Do you happen to own a um2 or ums2? The cover on the box of the um2 shows it can measure internal resistance (screen), but not in the description nor any reviews, while the ums2 both shows and documents that function. Is paying 2x the price ($14 vs $28) worth getting a internal resistance reading for above average (but not expert) users of rechargeable batteries? Thanks.

[@MrBazReviews]

UM2 is same spec just 2 bays less, IR test isn't that accurate best feature might be variable charging rate/speed ie user selectable

[@Orvis25]

@@MrBazReviews but does the um2 series measure internal resistance? If so, does the ums2 series have more accurate measurements of internal resistance then the standard um2 series, or is the only major difference between the two the increased charging rates depending on power source?

[@lorandhorvath4466]

@@Orvis25 UM2 does not have IR measurement. The others have it: UMS2, UM4, UMS4.

[@deandemafiles4162]

I have the ums4. My battery capacity display is 0000mA but all other like IR, voltage batt health display is working. How do i fix this?

[@MrBazReviews]

If it's not counting the mAh then it's not working correctly so get in touch with the place you bought it from

[@bernardtan1]

Does the UM4's LCD screen go DIM after 10 minutes of inactivity or no pushing of C & V buttons ?

[@MrBazReviews]

It dims after 3 minutes

[@l3875]

I have this charger but I don’t know how to fully charge a IKEA LADDA 2450 AA batteries, any idea?

[@MrBazReviews]

You just put them in the charger I mean that's what a charger does right?

[@mattcousins1707]

Hey Baz - can you run the UM4 off of your Suaoki solar panel? Thinking of doing this, just not sure on the minimum current to keep it running.

[@MrBazReviews]

It will run on a low ish current under 1.0A, but winter time off that panel forget it for any serious charging. Summer it will work fairly well. I would normally go with a single or dual slot charger off that panel

[@paulb2769]

Curious what you would recommend to charge NiMH - AA & AAA's? For flashlights 🔦. A 2 slot simple charger / don't need fast charging but one that would extend battery life! Thanks much!!!

[@MrBazReviews]

Up to 1 amp AA, 0.5 amp AAA is usually a good bet

[@paulb2769]

@@MrBazReviews After doing more research I found a Klarus K1 single cell charger. Would you recommend this one? Or do you have another recommendation ? Thanks again!!!

[@MrBazReviews]

@@paulb2769 I still use the K1 it works fine assuming it fits the battery sizes you want. You can control the charging speed I use it quite a bit

[@arisuryapagi]

Why when you charging NiMh( on video) , the voltage until 1,56V to cut off? In the box that write 1.48V(+/-1%), why that, maybe you know

[@MrBazReviews]

It's delta V, very common for cells to hit just over 1.5V

[@cheeseyboy2121]

does this charger discharge the batteries before charging for longer life, if not what charger would you reccomend?

[@MrBazReviews]

No discharge on this one, try the Opus charger

[@chefgav1]

I agree about the resistance tester.I charged a brand new 26650 at a resistance of 350 when it said charged at 4.2 i changed slots and with same battery it went to 170

[@MrBazReviews]

Yes it's not accurate so something for Nitecore to work on I think. Not a major issue as the other areas are working well but it's strange. Just important to not rely on the readings to determine battery health

[@chefgav1]

Mr Baz Reviews yes.I saw one vaping review on this charger and the tester said he threw out a lot of batteries because of test lol. Your review is excellent.Thankyou for taking the time.

[@MrBazReviews]

@@chefgav1 Thanks for the comment. I cross compare results so with the Dragon I can test IR also as it didn't match up or close even allowing for the circuit adding to the figure (which it does). Higher IR doesn't mean cells are useless (they can drop voltage if it's really high) it's the capacity that is most important and easily tested. Worn out cells have much lower capacity

[@ziarehman2357]

Mr baz What would be the best charger to charge most li-ion battries for flashlight high drains and others 'protected n unprotected' .that every port charge separtely ,charge discharge shows battries capacity.there are plenty on the market and it hard to decide.your kind suggestion please Thank you

[@MrBazReviews]

For cost Opus or Zanflare C4 they are both decent enough

[@ziarehman2357]

@@MrBazReviews opus bt300 than Thank you Mr baz

[@Neonb1bLes]

What’s the difference between this and the SC4? Total 6amp charging and a different power cable is really all I see.

[@MrBazReviews]

Quite a few longer slots on the UM4, display better on SC4 and that is also mains powered

[@bikesandfamily3082]

Very good review. Just bought one. Curious if it automatically charge fast when using fastchargers? Or do you have to manually change it on settings? If so how do you do it? I am using samsuns 18650 battery. Sorry english isng my first language

[@MrBazReviews]

It doesn't make any difference default speeds are same, it just lets you use more power for more channels ie faster on the other bays

[@bikesandfamily3082]

@@MrBazReviews is it faster if you only use one bay?

[@MrBazReviews]

@@bikesandfamily3082 No because it's 1.5A per bay the S one can do faster charging it's all shown in the video in detail

[@VeritasVortex]

How does this compare with the Liitokala Lii 500?

[@MrBazReviews]

This is a charger which might appeal if you want to charge say protected 21700 cells or use the USB. The Lii 500 is more a charger/tester. Depends what you want to do

[@koleuslybra]

Very dissapointwd about this charger... please help me in order to better understand how to find the total capacity of the battery; it's the value displayed at the end of the charge? or to that value I should add the initial value is displayed when inserting the battery? Thank you so much!

[@MrBazReviews]

Ma is the charge current, Mah is the capacity charged into the cell. To make it of use, discharge the cells then charge them, it will count the capacity charged into the cell. For me there are 2 issues, the strange IR readings, and the problem with small cells slipping off the contact points (AAA in particular), otherwise it's an alright charger. But I would like to see a good charger/testing unit from Nitecore

[@koleuslybra]

Thanks for the response! So actually, the battery needs to be completely discharged, in order to have an accurate reading... otherwise will show the value from that moment it`s charging, regardless what`s already loaded..

[@pedropedroza345]

I was thinking that the um4 predermined choice 1000mA per battery but if you put 4 batteries, are 4000 mA in total, do you if I need to adjust the slots? Because the obtion 750mA is not available

[@MrBazReviews]

The video explains everything charging speeds etc

[@pedropedroza345]

@@MrBazReviews yeah I saw the video but I don't understand everything, because I don't speak English bus thanks

[@kakegarcia8056]

Hi! Many years ago I used an ENERGIZER fast charger and I discover I was damaging all of my batteries so I have learned that fast charges are not good at all. So, is this one of those fast chargers? I have a power bank which delivers fast charging and I am looking for a good USB charger but I do not want to fry my batteries again. Thanks!

[@MrBazReviews]

The reason I made the video is to answer these questions it only takes a few minutes to get all your answers

[@kakegarcia8056]

Mr Baz Reviews And I thanks you su much. I saw the video but even though my doubt remains

[@micjubba709]

It's a detailed stats charger with various options to charge fast or slow and will tell u if batteries are good miles better then standard energizer one

[@khadeemzbashr44]

Nitecore UM4 or SC4 or Golisi S4?? Which one is good for 18650/21700 batteries? I use batteries only for vaping.

[@MrBazReviews]

They both work fine this has more features and charging control either will do watch the S4 review to decide: kzbin.info/www/bejne/gZDQcn5thNh_nrc

[@j.p.4541]

USB charging cable for a 4 battery charger? I have a D2 charger and it has a dedicated wall charger. I wonder if one is better than the other?

[@MrBazReviews]

D2 is OK this one can be 5V or quick charge, some folks like USB as it's portable It has more options v the D2 and you can get a 2 bay version

[@jamaiahahmad1472]

hello mr baz. did this UM4 show how many amp we charging per bay like xtar vc4? because i cant see it at the video

[@MrBazReviews]

It shows the charging current just cycles between that and IR, voltage, charge capacity

[@jamaiahahmad1472]

@@MrBazReviews what is charging current? its what we set how much volt we want per bay right?

[@kalmer5410]

Can this be used to charge samsung INR18650 35E cells?

[@MrBazReviews]

If it fits it works it's not brand specific erm 18650 is an 18650

[@oscremozzo]

Hi... 4,2v or 4,3v make any diference while charging?

[@MrBazReviews]

4.2V is the one for most Li-ion cells

[@mmortada1978]

I bought iclever 24 w dual USB ac adapter model: ic-tc02 Output : 5v 4.8A (each 2.4 A max) Does it fit with thats um4 charger to charge my vaping battery 18650/20700/21700

[@mmortada1978]

I have already D4 using now

[@MrBazReviews]

It will work but you need higher voltage for quick charge

[@mmortada1978]

@@MrBazReviews Which what write for me specifically one from your choice or share me link

[@Say0n]

I have error in slot 4 EE EE and there's nothing connected :/ and it is almost new!

[@MrBazReviews]

EE means it's not charging if a cell is inserted try pressing both buttons (press and hold) it starts the low current activation

[@-djs]

Hi there Mr Baz, Do you know if the battery trays on the UM2 are the same length as the UM4?, Many thanks,

[@MrBazReviews]

They should be from photos I've seen

[@-djs]

@@MrBazReviews Hi there, Thanks for the reply, I think that's the quickest reply I've ever had, I shall be ordering on shortly, Excellent reviews,

[@sylvesterstallone549]

whats the difference between the Nitcore UM4 and the UMS4?

[@MrBazReviews]

6:40

[@sylvesterstallone549]

thanks just ordered one

[@MrBazReviews]

@@sylvesterstallone549 No probs I think the UMS4 is for vapers or those using high drain cells more as the default charging speeds are quicker, and you have more power (when using QC). For me I think the UM4 is better as I use a lot of protected cells so I rarely have to change settings

[@sylvesterstallone549]

It’s perfect for me then since im a vaper. I own a nitecore d4, had it for about 2 years. I was in between a golisi, Xtar, and decided to go with Nitecore for my vaping batteries, hopefully it’s as good as my D4. my d4 still works but I feel that it’s time to upgrade. Could QC affect my 21700 and 18650 batteries in the long run? or should I charge them normal? I’m a noob when it comes to this.

[@MrBazReviews]

@@sylvesterstallone549 Above a certain charge level it affects the no. of cycles some high drain 18650's can handle a big charge, and 21700's also are able to deal with it. Honestly for high drain cells 2.0A is fast enough, once you start going to 3-4 amps it's hitting the no. of cycles you'll get. Vaping eats batteries as they are fast discharging (using higher power mods), if you do normal charging speeds say 1-2 amp you'll get longer life out of them. Fast charging and discharging will give less cycles. I know vapers who get 6-7 months out of cells before they notice a big decline in capacity (as the cell wears out). I only use a single 18650 mod so I just keep spare cells and charge them at normal speeds.

[@daveycrockett5738]

I just got some batteries I ordered and they are the SAMSUNG 30Q 18650 3000MAH 15A BATTERY. One says 355m and some weird looking circle thingy and the other says 283m and then some weird looking circle thingy next to it. I’m new to all this battery charging stuff but had to get some for my new flashlight. I know you said the ums4 reads high in that aspect but is this too high and what does this mean. Does this mean these are used batteries or should I be ok because the device already reads high in that aspect? Also when I’m in the settings menu what does it do if I change the ma. Is that what charges it faster or slower? What does the mah number mean when it’s just being charged? And then also what does the ma reading mean when In charge mode? Thanks guys!!! I also have the Miboxer C4-12 on the way, I’m wondering if that will give me a more accurate reading. If not what can I buy that will give me a more accurate reading of the m and the little circle thingy? Good luck 🍀

[@MrBazReviews]

I'm super busy so don't have time for in depth replies. You can google most of the questions and the review covers the other areas like internal resistance. High IR readings won't effect charging

[@daveycrockett5738]

@@MrBazReviews is it bad to have high ir? I just bought these batteries they should be brand new why is it so high?

[@MrBazReviews]

@@daveycrockett5738 As the review says the IR measurements are inaccurate (hugely) so cannot be relied on. So don't ignore them

[@daveycrockett5738]

@@MrBazReviews you mean ignore them not don’t ignore them? Some of them are low, it’s confusing.

[@MrBazReviews]

@@daveycrockett5738 If you watch the review nothing is confusing I clearly say the IR measurements are completely inaccurate so you should not buy this if accurate readings are required. I can't be any clearer than that. As a charger is works pretty well, for IR testing it doesn't at all. So if I say IR is not accurate why would you be concerned about the readings?

[@zynaryzaidi7883]

Am bout to buy this charger. Does it charge my fujitsu battery 1000mah for my tamiya mini car?

[@MrBazReviews]

If you read the description/watch the video you will know what types of cells it charges

[@zynaryzaidi7883]

@@MrBazReviews how.long does it take

[@MrBazReviews]

@@zynaryzaidi7883 Charge at 0.5A for AAA, divide capacity by charging rate for a rough idea

[@Orochi_001]

I love the simplicity of my D2. What’s a good option if I want to see a bit of extra diagnostic info like mAh?

[@MrBazReviews]

There is a 2 bay version on this charger (giveaway for 3 of them right now) same functions as this ie counts the mAh charged into a cell

[@猫不吃鱼儿]

Great Reviews, help alot.

[@MrBazReviews]

I try thanks for the comment appreciate it

[@ThalesRod]

There is any test function?

[@MrBazReviews]

No discharge test, you can however count the capacity with flat batteries. Gives an idea of capacity

[@hdi08]

What does the CC, CV mode mean?

[@MrBazReviews]

Constant Current/Voltage

[@pumpqnbelly3895]

vro, when setting changed are thos setting are reset when im unpluged the power???

[@MrBazReviews]

Yes reset when powered off all chargers I've used to that

[@CartubeCoIl]

Thanks for the review. I don't understand why they didn't use USB type C. Almost no one use micro USB any more and since it's kind of travel charger I'll need to make sure I bring two cabels and not just one. I will have to skip this one.

[@MrBazReviews]

Type C is becoming the standard, though micro is still very common. Long term it would make sense to use mainly type C, probably not a deal breaker though

[@simonspencer397]

Yeah, hardly anyone uses micro usb anymore, apart from the hundreds of millions who do.

[@cjr1881]

@@simonspencer397 only new stuff is usb-c. Micro usb is still way more popular if you want the facts.

[@cjr1881]

Micro usb is more popular

[@simonspencer397]

@@cjr1881 Here, have a parrot. Whoosh

[@gabsantiago7676]

Hello Mr Baz, I have an request to review XTAR VP4

[@MrBazReviews]

I'm not sure if I will get more samples from Xtar who knows but I can ask if I have contact from them again

[@gabsantiago7676]

Mr Baz Reviews nice, thanks mr baz. I know xtar vp4 is pretty old but it is a good charger

[@rvalentino3565]

Can u named 3 good battery charger (4 slot) with IR measurement?

[@MrBazReviews]

Opus or the Zanflare C4 are decent enough at the price

[@Aranimda]

Will it fit 4 D-cells?

[@MrBazReviews]

Will fit 2 on the outside bays

[@blueback21]

which is best for AA and AAA

[@MrBazReviews]

It works fine for AA/AAA smaller cells might need jiggling about a bit that can be annoying. VC4 also a decent charger for Ni-MH

[@uriahsteele1887]

Can I use a apple iPhone wall plug in for this

[@MrBazReviews]

Yup though it depends on the speed most should work fine

[@mmortada1978]

Which adaptor can be used with that's type of USB cable

[@MrBazReviews]

You can use any USB port but you need a QC compatible one for the fastest speeds (ie extra amp charging across the 4 slots) or a 2.0 amp one. Any USB will work even a 0.5A port but it's going to be pretty slow.

[@mmortada1978]

@@MrBazReviews Sorry I have 3 phones chargers Nokia normal Samsung note 4 fast charging Huawei mate 10 type c fast charging Which I could use and gives me the fastest charging

[@MrBazReviews]

@@mmortada1978 Check the specs on the adapter see if it supports QC if not then the amps output (usually marked) ie 1.0 or 2.0 amps.

[@ggyubari5687]

Can it tell me the capacity of my battery? How do I check that?

[@MrBazReviews]

Fully discharge then charge it

[@ggyubari5687]

@@MrBazReviews Yeah, was wondering if there was any indicator, but thanks anyway.

[@MrBazReviews]

@@ggyubari5687 There is no way to get an indicator of capacity unless you perform a full discharge or charge cycle on any charger. With this one it counts the charge into a cell not as accurate as a discharge - but close enough to be useful.

[@reifenabhobeler4331]

Don´t have much did with the UMS4 charger, so only a short conclusion from me: + Build Quality, compatibility to many cells, good amount of charging currents. o Display (less information, only one bay at one time), AAA fits not good - 1A default current for AAA, only two buttons, with some NiMH-cells termination-problems, Power Supply not included, sensitive Micro-USB What´s really annoying: Shared slots; 1+3 on one circuit, 2+4 on one circuit. The charge current gets halved if you put 2 cells in at one circuit. OK, you can say now I just have to use the double current to get the speed, but if one of the cells is full the other one gets the double current. Hope Nitecore will learn in future and stops Bay-sharing, and it would be nice if they include more functions like discharge, more informative display and better operating concept

[@MrBazReviews]

I was hoping they would update their chargers to fix some annoyances, but it's not happened so far very few new releases from the company. These are OK chargers, but there is potential for much better ones.

[@reifenabhobeler4331]

@@MrBazReviews Yep, and so far it was the only brand who answered me a question, at least in a very short sentence. Skyrc, Xtar, Dlyfull and ISDT never answered.

[@MrBazReviews]

@@reifenabhobeler4331 Doesn't shock me at all I've found most makers to be downright awful responding to questions/problems, often simply ignoring them. That's what I hear, and I've had poor experiences myself from some makers. Nitecore, I give them credit, they keep sending review items in, and don't complain about negative points mentioned (some makers like Olight just black list you for negative comments on products), and they do seem to reply to people, that's what I hear anyway. So, whilst I'd like some updated chargers and improvements, at least there is some kind of support service there! I gave up on Xtar a good while back, their QC is all over the place

[@reifenabhobeler4331]

@@MrBazReviews I want to mention Vapcell positive. I never asked them directly but they are active in Budgetlightforum and ask for features for the upcoming chargers. And they answer the questions from the users. I would be happy if their next charger really have the requested features.

[@MrBazReviews]

@@reifenabhobeler4331 Yes I see that, they were supposed to send some chargers in, but never got round to it, I see they updated some models who knows maybe I get hold of one to try.

[@arisuryapagi]

I have UM2, and consistent / stabil , will cut off at voltage 1.48V when charhe NiMh

[@MrBazReviews]

See other response, you can't take the charger reading it has to be off the cell

[@TopDog8762]

With the exception of the internal resistance measurements this seems to be a winner. A USB power bank feature is a nice extra, but not really important to me.

[@MrBazReviews]

The mostly got it right the power bank is a small point not really important but some like it. Shame the LCD doesn't dim more or able to turn off, though they charging speeds are spot on for different cells. Simple solution using the contacts to know if smaller or larger cells are inserted and the long slots for protected 20/21700 cells is a big one which should future proof it. Very few chargers can take those cells at the moment, and they will be much more common in years to come. Not sure what's going on with the internal resistance

[@chefgav1]

@@MrBazReviews not many digital smart chargers out there take 21700.great review

[@ericsuper2]

Dear Mr Baz, please may I know if the blinking bar reflects the remaining capacity of the battery? Thank You

[@MrBazReviews]

It let's you see the charging status ie more bars = closer to fully charged The mAh is the capacity charged into the cell, so for testing discharge cells not as accurate as a discharge test but still of use

[@kmuralikrishna1582]

@@MrBazReviews It seems like this charger is only to charge cells but not to get internal capacity means it don`t have discharge function.

[@ShijilThachilodi]

can we use this to test the lithium ion battery capacity ?

[@MrBazReviews]

If you fully discharge the cell it counts the "charge capacity" so that will give you a decent idea. It's not as accurate as a discharge test, but it's close enough

[@gray_wolverine63]

Thank you. 😊

[@MrBazReviews]

Any time!

[@gray_wolverine63]

@MrBazReviews I just received mine UMS4, and after looking at it and using it, I was impressed. I was going to order the UMS2 next, but when I just saw the price difference, it was only $10. I Instead, order the same UMS4. My primary use for this unit is to change my scuba diving lights. Hopefully, they will last as a scuba diver. Two is always better than one. Thank you again. 🇺🇲 👍🏼

[@MrBazReviews]

@@gray_wolverine63 Yes the price is close on both for some reason, still a few niggles aside they are decent enough chargers. Perhaps Nitecore will do some new versions soon

[@RichardCyberPunk]

the disabiliy to turn the display off is bad when using a solar panel. Otherwise I would buy this charger.

[@MrBazReviews]

Yeah it's a bit annoying and the fiddling around with small cells (AAA mostly) can be tricky to get them charging. It's alright in other areas - Nitecore haven't been doing much in chargers recently, I keep telling them to update the D4 and make a proper charger/tester!

[@Bergwacht]

i neede just a cheap charger for 18650 cells. iam fine with this thing.

[@MrBazReviews]

It's fine for 18650 just the AA/AAA's not ideal (not enough spring pressure)

[@Bergwacht]

@@MrBazReviews what? i can charge these remote control batteries? nice!

[@MrBazReviews]

@@BergwachtAs the review mentions I had issues with some Ni-MH cells contacting correction (AAA is by far the bigger problem)

[@HamedVape]

Tnx