Year 2025 UNIROSS compact NiMH charger with 9V charging ports UCU004 Mini Review

[Kiriakos GR]

UNIROSS - France, this is an invisible company, regarding internet marketing.
I am clueless of the quality of their Chinese import of NiMH batteries, but this topic it is relative to UNIROSS NiMH chargers alone. 

UNIROSS UCU004 Compact ( Input Source Micro-USB & Type C) 
This is a product design of the year 2021, product availability started at 2022, now at 2025 UNIROSS selected to discontinue this model, reason unknown.

UCU004 Compact this is marketed that supports six individual slots, supports Negative DV detection, along charging timer.   
Charging currents:
AA 300mA   
AAA 120mA
9V 35mA

This is an excellent choice of charging currents, especially for AAA in combination with Negative DV detection.
I got motivated due product datasheet alone, and I did buy one, this is from last available Greek stock.

In general, UNIROSS UCU004 datasheet this is poor at explaining technical details.   
After charging complete for AAA & AA, there is no information, if there is Trickle charge?
Is Negative DV detection also active at 9V slots?
At 9V 35mA there is no reference of max supported in capacity 9V Battery.

I did use a cross-reference several UNIROSS datasheet,  and in my surprise, UNIROSS skipped entirely the use of Negative DV detection in all of their chargers.
UNIROSS UCU007  Dual 9V charger, this also at 35mA per port, this will use a 10 Hours timer as charging termination. 

Currently available UCU009 compact-basic model this is a stripped down version of UCU004.
This is a very slow charger, constant current mode, its does not cause harm at the batteries, but this is not worth such a high retail price either.

UNIROSS brand, after receiving three email from my end, they did talked back, they did verify that at 9V ports, their products support timer protection, and or no protection ( UCU009).

And finally, due inspection of UCU008_UNIVERSAL datasheet, I did found a clue of supported 9V capacity under 10H Timer.
Charging Time range   9V 200 – 300 mAh 8-10 Hours .............

Yes, combine four datasheets so to find the truth,  this is the UNIROSS way. 

-----------------------------------------------------------------------------------------------------

I do feel partially optimistic about this UNIROSS UCU004 Compact ( Input Source Micro-USB & Type C)
If it proven to work as advertised? Then I will buy few more, and I will stop using all these ANSMANN chargers, with the aggressive charging current presets for AAA and 9V.

UCU004 Compact  
This requires external power supply of Micro-USB or Type C, this charger uses some sort of DC/DC 5V step down Buck for AAA & AA.
For the 9V ports, this must be using  DC/DC 5V to 11V step up buck.
Along of Micro-controller for Minus DV detection.
Along of a another Micro-controller as six channel timer.

In a few days I will be the first to discover, if UCU004 Compact this is truly a charger this designed to include innovation, or a false presented low-end gadget?   

Attached few stock images, after arrival I will say more.

Note:   IKEA STENKOL this has similar features set, and using Holtek HT46R004 IC.
I truly hope to see something even better at this Uniross charger.

[Kiriakos GR]

Charging Time range   9V 200 – 300 mAh 8-10 Hours ..

According to math calculation for battery charge table.
280mAh  * 1.4 = 392mAh / 0,035A = 11.2 Hours

Identical calculation with a lower factor.

280mAh  * 1.2 = 336mAh / 0,035A = 9.6 Hours

Unorthodox calculation with average 1.3 factor.

280mAh  * 1.3 = 364mAh / 0,035A = 10.4 Hours

The truth this will be found after my own actual testing / mini review.

[Kiriakos GR]

Lets go, unboxing.     

UNIROSS User manual = useless printed paper, with a single instruction, install first the batteries then plug the charger to USB supply.

UNIROSS Micro USB cable = Just an 22cm long cable, the wire hard as to was made by plain iron, an useless accessory.

UCU004 production of 2020, this has large in diameter rubber feet.
My UCU004 production of 2021, this came with smaller in diameter rubber feet.

When the charger this is plugged at the PSU, there is no LED activity, for a minute I thought that this is DOA.
But the PCB this is alive,  there is no DCV output anywhere, but the DMM it can measure in AC mode, pulsing voltage.

UNIROSS UCU004  Micro - controller
All information's erased, I am unable to verify if this is an Holtek IC, or custom work.

I started testing right away the 9V slot, I have here a fully discharged battery from yesterday.
The charger started to deliver almost 40mA right away,  under 30 minutes of temperature stabilization,  long pulse this is at 30mA.
Indeed charger specification this mention 35mA, but the battery this is old with high resistance, and anything that I do measure this is as expected.
UCU004  Micro - controller, it does a good job, and I am very happy and calm, the operation of 9V Slot this is excellent.

But there is something peculiar at the current curve,  in theory 9V charging this is supervised by timer,  but the charger makes short and long pauses.
Short pause, this is indication that there is active a voltage monitor ...  my new question ... Do I have minus DV sensing and at the 9V slots? 
Or this can be just an inspection, from the side of Micro - controller, if there is still a battery on that slot. 

   
First technical impressions:
This charger has manufacturing date 49 week 2021 ( 6 ~ 12 Dec 2021).
The soldering is very good.
PCB design modern.
AAA negative pads they are separate, from AA negative pads.

AAA and AA charging system, this will be inspected later on.
All that I can say, this is so far, so good !! ( despite the poor  user manual, and the cheap and useless Mini USB cable. 
   

[Kiriakos GR]

But there is something peculiar at the current curve,  in theory 9V charging this is supervised by timer,  but the charger makes short and long pauses.
Short pause, this is indication that there is active a voltage monitor ...  my new question ... Do I have minus DV sensing and at the 9V slots? 
Or this can be just an inspection, from the side of Micro - controller, if there is still a battery on that slot. 

Dear Kiriakos, you do have minus DV sensing and at the 9V slots 

But guess what ?  The Moron whom programmed the Micro - controller, he made a huge mistake.
If you add a fully charged battery, and voltage termination this get at 10.454V  in five or seven minutes of time, the LED on the charger this flashing as to was an Error condition.

Yes its embarrassing for UNIROSS, this to explain at consumers,  that this overall super smart 9V circuit, this deliver erroneous information's at the user.
Due this programing error, and while this is irrelevant with charging system functionality, UNIROSS selected to discontinue this product. 

Mixed feelings but 95% in the positive direction for the 9V ports.
UNIROSS UCU004, it is now verified that I have in my hands, an charging system this working correctly according to electrical specifications, for 9V NiMH charging.
Minus DV sensing = Pass
Termination voltage = Pass
Charging current = Pass
Trickle current = Pass

What I missed to inspect, and I have to recheck, this is actual timer limit, I did use an old battery with 193mAh capacity,  this was charged for 9:56 minutes,  the charger when to Trickle, I was not here so to verify of what kicked in first.
The charging ended due Timer decision, or due reaching the termination voltage?

About the micro-processor,  and it programing bug, I do not care that much, but this is because I gained enough confidence due my own in-depth tests 
Is this programing bug part of the 1.5V charging system too?  This will discovered in 24 hours from today.   

[Kiriakos GR]

New pack of discovered experiences due AAA testing this time. 

UCU004 at AAA charging it uses an super fast pulsing storm  
I had to switch measuring setup,  and use instead my FLUKE 8846A this capable for 14 recorded measurements per second.
At 5 digits resolution, 1 PLC,  I am now able to record REAL TIME DC current measurements.

At UCU004 name plate, and charging currents per battery type, this is a number which comes from Averaging of delivered magnitude of a pulse within a specific time domain.
Naturally the best instrument for time domain explorations, this is one oscilloscope, but one super fast and high precision DMM, this is the appropriate tool for accurate electrical measurements.

Due my U1272A an fastest HH DMM, I did understand due the bar-graph, that now my charger this has an output of much faster pulses, these be beyond of this instrument capabilities about be recorded or measured.
Especially and due a Bluetooth connection.

I am now exploring the charging process
I did discharge four LADDA 750mAh AAA, with my computerized battery discharge capacity tester, with 50mA discharge current.
All four batteries when down to 0.9V, and they were ready for charging.
Right now I have leave my UCU004 to charge them.
I have add single DC current monitoring setup at a single battery.
I am currently recording for 5H 9M and charging this is still going. 

One of my happy moments, this is seen my 8846A, this measuring and verifying the averaging of 120mA for the AAA.
https://www.ittsb.eu/TsDMMViewer-Data-Logger-2020-Japan&Greece.html

Another one of my happy moments, this is monitoring charger and batteries temperature under charging.
Ambient 21C
UCU004 plastic casing  25C
Batteries temperature 27C  =  Remarkable 

[Kiriakos GR]

This charger it is a great school for me.   

Indeed AAA charging system, this is different from the 9V Slot.
Uniross UCU004 micro controller, this is programed to do things differently.
When four batteries charging = we have high speed pulses with accurate current control.
When two batteries are full and two charging = we have medium speed pulses with accurate current control.
When three batteries are full and one charging= we have slow speed pulses, DC current this become stable at 120mA.

This is my first charger supporting Auto Cut-OFF, instead of trickle charge
This is something new, how it is possible one charger to perform Auto Cut-OFF?

I will start explaining this by the reverse order,  without DC power, the charger causes at AAA slot one current draw of 36 Micro - Ampere  (1000 uA = 1 Milli Ampere).
36 Micro Ampere this is a tiny quantity,  but in long term this is able to work as electrical DC load.

Uniross UCU004 micro controller, this perform this Auto Cut-OFF, by sending or feeding the AAA port with DC current of 190 Micro Ampere.
By doing so, charger electronic circuit, this zeroing any loses from this be an passive load, this draining down battery charge.
190 Micro Ampere this has zero impact for the battery, if we think of it as trickle charge.

Charging voltage this gets as high as 1.5V,  and when charging stops, and after a few hours, all four batteries they simply are in a relaxing state.
Charger LED stays on:
Battery voltages after 8 Hours:
1. 419V
1. 419V
1. 422V
1. 422V 

Voltage differences down to milli-volt this is relative to battery condition / internal resistance / actual battery capacity...
And or charger passive electronic component tolerances +/_1% or other.

What we should focus on, this is the smart technique in use, so the charger to become an invisible load for as long the batteries they are not removed from it.

Bellow there is a rare electrical measurement.
High speed / 1mA Range / 60 seconds

Measuring accuracy this is warranted by the measuring instrument, and due a high qualify DIY dual-side pad, this made of 100% real copper.

[Kiriakos GR]

What happens if you add half charged or fully charged AAA at the UCU004 ?

In this type of batteries, the micro controller this does exceptional work. 
Even fully charged batteries, accidental restart, they will have a quick charging cycle of about 16 minutes.
The charger will start lowering it three modes pulse train, according to how many batteries they get classified as fully charged over time.

What it does pleases me with this specific charger, it does charge the batteries and them, they stay at low temperature from start to finish.
I definable buy and a second one. 

For all the nerds out there, I did one image with Peak DC currents, this charger generates three steps pulse train.
And the smart micro controller, adjusts with precision the average DC current per battery.

Next to be explored .... AA 1.5V slots       

[Kiriakos GR]

What it does pleases me with this specific charger, it does charge the batteries and them, they stay at low temperature from start to finish.
I definable buy and a second one. 

I got triggered to discover, of how its possible, this charger to not cause heating at the AAA batteries?

For a first time, I am recording and monitoring the entire progress of a charging process.
And I feel truly amazed due my discoveries, UCU004 this using at least three different charging patterns.

First pattern = First hour full speed.
Second pattern = 20 minutes half the charging energy / 20 minutes full speed
Third pattern  =   30 minutes half the charging energy / 10 minutes full speed

It never stops charging, it constantly selecting a different charging pattern, with ultimate target, all four batteries to stay at bellow 30C, no mater what. 
Over all battery temperature this is 4.5C above ambient for AAA.

Charger case this is 2C above ambient at charging AAA. 

[Kiriakos GR]

The sum of charging patterns these are four  

At this charger the operation of Trickle charge, this is not here.
There is instead an fourth pattern, this named as: Low current Top UP
The duration of this pattern at the time domain, this is not fixed.

If you charge a half full battery, the charger keeps this Low current Top UP for approximately 30 minutes.
If you charge an empty battery, the charger it might decide no using it at all, or activating it for less than a few minutes.

Never seen before so much added thought at Micro processor programing within a NiMH charger!
This comes close to self driving vehicle concept.
Since the insertion of a battery, this charger will measure battery voltage, and it decides the charging patterns sequence all by it self.
Is it empty?
Is it half full?
Is it charged but not fully?   

Another detail not that obvious, this is the attempt of the charger this to deliver voltage balancing, it goal this is to deliver four charged batteries and its one this staying at 1.44V as fully charged.
No there is no Ghosts here    
No I do not imagining things, its simple hard for me to transfer in to words, all the information that I can see within my recorded measurements.

This new attached image, this has value as time domain measurement.
This has also value as demonstration of how smart this micro controller behaves, as it does micro metric adjustment at current control over time, all by it self.

An linear power supply cannot behave that way.
An digital programmable power supply, neither this cannot behave that way, it can execute a few commands, and it can use a single programed pattern.
Long story in sort, there is no bench-top power supply, this be able to do all the tricks, that this charger is programed so to perform.

[overvolt]

Excellent work at testing, I could never imagine that this Fluke 8846A, this is such a speed daemon. 

At high resolution its a king at measuring precision, at low resolution this imitates the work of an Oscilloscope.   
I am truly impressed of what this 8846A can do.

And about the charger, this is truly another one impressive gadget!

[Andrew-88]

Excellent work at testing, I could never imagine that this Fluke 8846A, this is such a speed daemon. 

At high resolution its a king at measuring precision, at low resolution this imitates the work of an Oscilloscope.   
I am truly impressed of what this 8846A can do.

And about the charger, this is truly another one impressive gadget!

Yes in a way, 8846A multi role capabilities makes it simile to F-35 Lightning II.
From the other hand, with out having an TRUE Expert pilot driving such a plane?  No one can enjoy a worthy demonstration of it hardware potentials.

Fresher Chinese designs of RIGOL and SIGLENT bench-top DMM, all of them untested by experts.
No one ever bothered to test them and to prove, that these can perform successfully high-Speed PC logged measurements.   
 
8846A this came from the marriage of American technology and Japanese components!
Two continents tested it performance and agreed, so this be in the production line.

Even so, a portion of praise this worth to be delivered at the Japanese software developer of Ts-DMMViewer Data Logger.
With out this high quality of software,  8846A this it would be still unable to deliver proofs of it advanced technology under the hood !!

[Kiriakos GR]

Yes T. Shimazaki did his part, I did my own, this collaboration was not easy, we also had moments of tension, but the fruits of our work these was of higher importance. 

Personally I do find pleasure, when a products solution, this delivering real world performance.
Its a nice feeling to know that you are surrounded by useful tools.