Experiences with Nitecore SC4

[aLyr]

Hello all,

I've been using the Nitecore SC4 charger for several months by now.

This charger shows for the selected bay in 2 second turns:
a) cell status (good/bad) + cell internal resistance
b) charge current + cell voltage
c) charged mAh + charge time

I do not find the value of the cell's internal resistance to be reliable.
For one and the same cell, there are remarkedly high differences from one charge to another.

The Nitecore SC4 does not charge LiIon cells up to 4.2V, although it shows this value at the end of charging.
Half an hour after charging, cells have 4.16V at most.
This is not bad, as this can enhance the lifetime of cells.

This charger also works slower than e.g. a Nitecore SC2.
But despite that, it keeps the cells colder during charging.

I do not exactly like to charge two cells at 2.6A each simultaneously, though the system current is 6A.
But I tried that with a Samsung 35E matched pair, and it worked very well.

There is also the capability to define 2 cells to be charged first; when done, the other cells will be charged thereafter.
A nice feature.
Depending on required charge currents, you might call it a 2 after 2 charger.

Though the Nitecore SC4 may have some deficiencies, it will remain my preferred charger.
It gives me some good information and does not stress my cells.

Regards,
aLyr

 

[aLyr]

At this time, I am charging a Samsung 30Q with my Nightcore SC4 as a single cell in the 4 bays.

At the beginning, the charger reported an internal resistance of 74 mΩ, which I found quite high.

Thus, after 2 minutes of charging, I disconnected the cell from the charger for a split second. Thereafter, the charger reported merely 67 mΩ.

This makes me feel that the charger's measurement of cell internal resistance is far beyond being reliable.

After 30 minutes, after another disconnection, the internal resistance was reported as just 61 mΩ.

Thus, when it comes to internal resistance,
I do not trust this charger at all, though it seems to perform well in other regards.

Anyway, it measures internal resistance only once at the beginning of charge and not thereafter.

So please, just ignore the indication of internal resistance of this charger, which does not seem to be trustworthy.

Regards,
aLyr

 

[aLyr]

Back to my single Samsung 30Q.

Charging it in the Nitecore SC4 took 1h24m.
In CV mode, the charger stopped at ~100mA,
which is quite OK.

Removing the cell from the charger, it did hardly feel warm, rather below body temperature.

Its resting voltage a few minutes after charging was 4.11V.

This is excellent, considering that charging up to 4.2V will reduce the lifetime of cells.

Other of my cells go up to 4.16V in this charger, but this is still excellent.
Main thing for longevity of cells is to stay below 4.2V.

(You may ask Mooch about this; he will probably confirm.)

Regards,
aLyr

 

[aLyr]

While charging a good old Aspire 18650 2.5Ah cell right now, I am asking myself when my charger changes from CC to CV mode.
I will have an eye on that in the future.

The cell, initially set to a charge current of 2.0A made it after 1h24m up to 4.16V resting voltage, with the temperature being below warm to the touch.
Again, this is a good value.

 

[flavourchaser]

I've been looking for a 4 bay charger that show the IR. This seems to fit the bill, so I bought one, just now. Thank you for the review.

 

[Mooch]

The IR measurement accuracy for most of these chargers is lousy. The DC internal resistance should be about 20mOhms or so for the Samsung 30Q. The AC IR is even lower.

It should also be consistent if you remove and reinsert the battery multiple times.

 

[flavourchaser]

It's a good rough estimate of how the battery is. It's better than nothing. But isn't the proper way of testing IR is with a load

 

[flavourchaser]

This is what I use atm. It's a 2 bay 18650. It also reads the IR. Upgrading with the 4 bay Nitecore SC4 sometime this week hopefully

 

[Mooch]

It's a good rough estimate of how the battery is. It's better than nothing. But isn't the proper way of testing IR is with a load

That charger may use a load to calculate DC IR. It can be a small resistor since all you need is a short pulse of current.

Measuring AC IR requires injecting a low current, low voltage 1kHz AC (I’ve seen 100mV/100mA used) signal into the battery and measuring its response.

IMO, an inconsistent IR measurement is worse than none at all. But, at a consistent though inaccurate reading can be used to track cell performance changes over time.

 

[flavourchaser]

I'm going to compare it with my ISDT when I get it, see how it stacks up.

 

[flavourchaser]

Just got the nitecore sc4 today, and compared it with my ISDT charger. The nitecore showed an IR measurement of 120m ohm while the ISDT showed 36m ohm. Not sure which one is correct there. This is on a Sony VTC6 new battery. The measurement is consistent it's not changing. Seems the ISDT charger is more accurate???

 

[Mooch]

Just got the nitecore sc4 today, and compared it with my ISDT charger. The nitecore showed an IR measurement of 120m ohm while the ISDT showed 36m ohm. Not sure which one is correct there. This is on a Sony VTC6 new battery. The measurement is consistent it's not changing. Just not sure which one is more accurate.

Are they measuring AC or DC IR?
The DC IR varies from about 15mOhms to 25mOhms for the 15A-35A cell’s we use.

IIRC, the VTC6 is around 22mOhms for its DC IR.

 

[flavourchaser]

Mooch I have no idea, I only go by what is says on the screen see my pic above of the ISDT

 

[flavourchaser]

Here's a pic with a pair of Sony VTC5A batteries. The IR measurements is a bit better on this.

 

[flavourchaser]

Here's a pic of the ISDT with the same battery measuring 20m ohms.

 

[flavourchaser]

Side by side pic of Nitecore SC4 and ISDT C4 chargers

 

[Mooch]

Appears that the ISDT is a lot more accurate.

 

[Mysteron]

I see a lot of sites advertise this charger as being 20700 compatible. I've also seen a couple of 'reviews' with 20700 in it, iJoys, though lord knows how.

I have a number of 20700 and none of them fit. The SC4 box and their own included instructions however do not list the SC4 as being compatible with 20700, max 26500 /26650. You can, if you are ultra careful, wedge a 20700 in between the contacts but it cannot go into the 'well' and sit correctly / safely, it just sits perched precariously (suspended by just the springiness of the contacts) and will break that contact easily. You could also easily damage battery wraps and put stress on the charger contacts. In addition, the charging indicator seems to lock up when batteries are inserted this way. The bays are simply not long enough for 20700, unlike the Xtar VC2/VC4 which takes them with ease and room to spare. Some of the sellers, following complaints (e.g. fast tech, Arron 3 on Ali Express), have since removed 20700 compatibility from their posted specs for the SC4. So I would definitely NOT buy this for 20700s. Pity, great charger.

 

[aLyr]

Hello all,

I'd like to add to my experiences with the Nitecore SC4.

Yesterday, I charged a Sony VTC5 in it, which I have since 2016-06-05.
This was its 40th charging cycle only. After 2 years, it is quite young in this regard.

My cells are typically reused in one of my mods about a month after been charging latest.

The discharging mod had been an
Eleaf iStick Pico 25.
In it, the cell's voltage went down to a resting 3.22V, which is quite a normal value.

(My Aspire NX75 mod, however, goes markedly lower; down to a mere 2.75V resting voltage. But I do not use it often any more.)


I charged the Sony VTC5 in the SC4 as a single cell at the default 2A.

First, the charger told me an internal resistance of 56 mΩ, which is too high a value, regarding what Mooch reported on this earlier in this thread on AC IR and DC IR.

Pittily, the charger decides if a cell is good or bad depending on the IR value it has found.
Luckily, it did not rate any of my cells bad so far.

The limit seems to be 120mΩ for LiIon cells.

Anyway, I looked at the charger's display of bars indicating charge progress.
I found this:

Bar 1 blinking : up to ~3.50V
Bar 2 blinking : up to ~3.80V
(If you want to charge a cell to only about its nominal voltage, stop charging while bar 2 has been blinking for a while; the display of voltage will help also.)
Bar 3 blinking : up to ~4.00V
Bar 4 blinking : up to ~4.10V
Bar 5 blinking : above ~4.10V until charging stops at markedly below 4.20V.

At ~4.06V, the charge current started to drop continually down to ~100mA at the end of charge.
However, the change from CC to CV was reported somewhat later than when the current drop took place. Not exactly precise.

½h after the end of charge, the cell was at room temperature and had a resting voltage of 4.15V, which is excellent. This means low stress on the cell and higher longevity, i.e. a higher number of charging cycles to be expected.

Regards,
aLyr