Nitecore UMS4 Intelligent USB Battery Charger

[3Avape_Dara]

Product introduction
The Nitecore UMS4 Intelligent USB Charger, with 4 battery slots, is designed to recharge your batteries fast, safe and efficiently. The UMS4 will reach a maximum total output of 4000mA when using a 2A output USB power adapter. When the charger is connected to a quick charge (QC) power adapter, the screen will show “Quick Charge” and the single slot will achieve a max output of 3000mA.

Parameters:
Input: DC 5V/2A or 12V/1.5A 18W (Max)
Output: 4.35V±1%/ 4.2V±1%/ 3.7V±1%/ 1.48V±1%
QC Output Current: 3000mA*1 (Max), 2000mA*2 (Max), 1000mA*4 (Max)
Standard Output Current: 2000mA*1 (Max), 1000mA*2 (Max), 500mA*4 (Max)
Compatible battery types: AA, AAA, AAAA, C, D, 10440, 14500, 14650, 16500, 16340 (RCR123), 16650, 17350,
17500, 17650, 17670, 17700, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22500, 22650, 25500, 26500, 26650, 26700

Features:
-Fast and Efficient Charging
-Intelligent USB Charging with Multiple Input Sources
-Compatible with USB adapters, power banks, solar panels and more
-LCD display reports real time information including battery health and charging status
-Automatically detects battery power level and selects the appropriate voltage & charging mode

Package includes:
1x Nitecore UMS4 Intelligent USB Charger

 

[DJ Colonel Corn]

How can the UMS4 put 2A into each battery (2 slots used), when the unti itself takes 3A (the charger is rated 3A and the QC charger is 3A) ?

I have yet to understand how this is possible, and, comparing charge times with the alleged 2000mA per slot in the UMS4 with the 1500mA of the UM4, the UM4 charges the 2 batteries FASTER.

So, could you shed some light on this situation for me ?

I bought the UMS4 for the additional charge rate, and any updated safety features it might have.

I AM using a 3amp QC charger, I've switched QC chargers on the two units so it's not that.

Any info would be a great help. I am also staggering them, using slot 1 and slot 3, or slot 2 and 4, as per the manual's instructions.

 

[3Avape_Dara]

How can the UMS4 put 2A into each battery (2 slots used), when the unti itself takes 3A?

I have yet to understand how this is possible, and, comparing charge times with the alleged 2000mA per slot in the UMS4 with the 1500mA of the UM4, the UM4 charges the 2 batteries FASTER.

So, could you shed some light on this situation for me ?

I bought the UMS4 for the additional charge rate, and any updated safety features it might have.

I AM using a 3amp QC charger, I've switched QC chargers on the two units so it's not that.

Any info would be a great help. I am also staggering them, using slot 1 and slot 3, or slot 2 and 4, as per the manual's instructions.

Hi there, for this question, please contact our customer service dept at support@3avape.com, they will reply to you asap, thanks

 

[DJ Colonel Corn]

Hi there, for this question, please contact our customer service

So far, no answer, after 8 days.

 

[DJ Colonel Corn]

There's a discussion about this charger here : Nitecore UMS4 Charger Question .

I've re-sent the request to customer service with a different email account.

 

[HigherStateD]

Just a thought, but a qc 3A charger is putting out 3A at 5v, which equals 15w. The charging voltage of the cells terminates at 4.2v, but the amperage will trail off as it approaches this, as for the less robust model charging faster, an uneducated guess might be those safety features you were wanting. Overheat protection could throttle charge rate drastically.

 

[DJ Colonel Corn]

might be those safety features you were wanting

The issue isn't really the peformance.
It's that they claim 2000mA per slot with two batteries, when the QC can only supply 3000mA.

 

[HigherStateD]

The issue isn't really the peformance.
It's that they claim 2000mA per slot with two batteries, when the QC can only supply 3000mA.

Right, but 5v @3A is 15w, where as 3.7v@2A*2 is 14.8w, so there is no issue that I can see.

 

[DJ Colonel Corn]

Right, but 5v @3A is 15w, where as 3.7v@2A*2 is 14.8w

What resistance are you using in your equation and where did you get it from ?

 

[HigherStateD]

What resistance are you using in your equation and where did you get it from ?

Resistance is irrelevant to watts law. I got my equation out of a physics primer. Watts = Volts * Amps

 

[DJ Colonel Corn]

OK right.
That is correct, Watts is Volts x Amps.
The max output of this charger is 18 watts.
So 4.2volts at 4amps equates.
I guess I don't understand why the QC charger and the Nitecore charger both list "3A" as their limit, then.
My myopic understanding of electricity is apparently showing.
Care to explain why they are both rated 3 amps max ?

 

[HigherStateD]

The 3 amps is at 5v. When you step that down to 3.7v, the available wattage stays the same, so the amperage increases to balance the equation.

 

[DJ Colonel Corn]

When you step that down to 3.7v

Even if you are using 4.2 volts, that's still within the charger's wattage output capability, at 18 watts.
4.2 volts x 4 amps = 16.8 watts. The charger is listed at 18 watts max output.

I understand all the math, I'm acquatined with ohm's law and watt's law already, and it al makes sense.
I guess my only remaining question was, why both the Nitcore charger and QC charger list a 3 amp max output, while in this scenario, 4 amps are being used.

Here's handy chart for everyone, you'll need this when you are (most likely) relying on building your own coils on your mech mods. It's also handy for discussions like this thread.

​

On the upper level of the image, showing Ohm's Law, E= Watts, I = Amps, R = Resistance.
On the lower level of the image, showing Watt's Law, P = watts, I = amps, V= volts.

 

[HigherStateD]

I really think my lack of understanding is now showing, as I'm not quite sure where the confusion is...

4.2v * 3.7a = 14.8w <= 5v * 3a = 15w

In this way, the charger seems to be supplying more amperage than it's getting, but that's ok, because it's not pushing more wattage than it's its pulling.
Based on how hot they can get, I'm surprised it's even that efficient.

 

[DJ Colonel Corn]

I understand all the math, I'm acquatined with ohm's law and watt's law already, and it al makes sense.
I guess my only remaining question was, why both the Nitcore charger and QC charger list a 3 amp max output, while in this scenario, 4 amps are being used.

I'm not quite sure where the confusion is...

4.2v * 3.7a = 14.8w <= 5v * 3a = 15w

uhh
the confusion is......
why the chargers list 3 amps as their 'limit' while it's clearly using 3.7-4 amps.

EDIT: You know what, it's OK I give up on this one.

 

[zoiDman]

Think 12v