Test/Review of Danae DUO 9000 (Sometimes it is also called MAHA)

Batteries and Chargers Chargers
1

Danae DUO 9000 (Sometimes it is also called MAHA)






This is a charger and usb power bank, it has space for two AA or AAA batteries and with a switch it can either charge them or be used as a usb power bank.



The charger is delivered in a blister pack. In the last picture I have collected all the markings, if anybody wants to read it.



The package included the charger, mains power supply, car power adapter, usb power adapter and a usb charge cable for something.



On the back the charger has a very thin barrel (ø2.35mm)connector for DC input, either 5 volt ot 12 volt can be used. It can be used for the mains adapter, car adapter and usb adapter. The usb output is also located here.



On the side is a 3 position switch: usb output, off, charge.



There is two leds, one for each battery, they are used while charging:
Red=charging.
Flashing red=Error or full battery
Green=charging done



The slots are the common two positions for AA and AAA batteries.







Measurements

  • When charger is selected, but no input power connected it will draw 0.3mA from the battery.
  • Charger will detect at battery at about 0.3 volt and start charging.
  • Led will light steady red during charge and flash on errros.
  • When charge is finished the led will change to green.
  • Charging on a full battery will show error, not green.



Charging NiMH



The charger uses a bit below 400mA charge current. It looks like it terminates on voltage, but there is a small temperature increase, i.e. the battery is full. The charging time is fairly long at 5.5 hours.



On the second slot it does not look like it erminated, but more like a timeout after 7.5 hours.



With the eneloop pro is is a bit difficult to see if termination is due to timeout or due to a real termination.



The XX are terminated on a timeout.



With the powerex it might be a real termination or timeout.



For the AAA it looks like a timeout after 2 hours 35 minutes.



Starting with full batteries the charger do stop, but with an error indication.



Again termination on timeout.




The charger will work with both 5V and 12V input and in both cases the terminations is on timeout.



M1: 41,0°C, M2: 39,5°C, M3: 31,3°C, HS1: 43,1°C
The charger generates a lot of heat for the low charge current.
Note: Thermo test is done with the supplied 12V power adapter as power supply.



M1: 45,1°C, M2: 45,0°C, M3: 39,7°C, HS1: 56,9°C
A quick opening of the lid shows the battery temperature.



M1: 41,7°C, M2: 42,7°C, M3: 39,5°C, HS1: 55,2°C
The batteries are slightly cooler if I am charging with the lid open.



The charger is fairly fast to start. The voltage checks are used to terminate the charge with error if the voltage gets to high.



The charger current is the same with two cells.



USB output

  • Usb output is coded as Apple 2.1A, this is wrong for 0.35A output.
  • When usb output is not loaded it will draw 3mA from the batteries
  • Usb output requires only one battery to work.





The usb output cannot deliver much current. The maximum is about 0.35A or 350mA.



Using two batteries does not really change it.



The usb output has an efficiency about 55%, this is resonable for the low input voltage.



I did my test with 0.25A output and with eneloop it could maintain the output for about 2½ hour.
Note: The efficiency if wrong because I only measure current for one cell and assume same current draw for both cells.



With two pro cell I got longer runtime
Note: The efficiency if wrong because I only measure current for one cell and assume same current draw for both cells.





There is a lot of noise in the output, even at this low current: 250 mVrms and 4.4 Vpp (Some of the spikes are more than 2 volt).


Testing the supplied power supply with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.




Conclusion

This charger uses a fixed time when charging, when it stops premature it will show an error. This is not a very good charging algorithm for LSD cells and the current is also too high to be useable for old style NiMH cells.
The manual warns agains using this usb power bank with a smart phone and as can be seen the current is way too low for that.

This is neither a greate charger nor usb power bank because the charger terminates on time and lots of noise in the weak usb output.
I cannot recommend it.



Notes

I found this device on Ebay from buykingkorea_seoul

Here is an explanation on how I did the above charge curves: How do I test a charger
Read more about how I test USB power supplies and chargers

2

Thanks for the detailed review, so I will not buy this one.

Question: I have a (14W) solar panel with USB-output. With the sky overcast the output from the USB-port is only 250mA but it still charges my (XperiaZ) smartphone. It will take ages to charge like that, but 250mA apparently is not too low?

3

As long as the phone stays in standby you can probably charge most smart phones within 24 hours.

If you know the battery capacity on the phone (say 2000mAh) and how long it last on it (Say 20 hours), you can estimate the phones current consumption: 2000mAh/20hours -> 100mA, anything above that will go to the battery. With the above numbers it would be 150mA, giving a charge time of 2000mAh/150mA -> 13 hours.

The above assumes the charge circuit in the phone is smart enough to handle the low current.

This device here only last about 3 hours on two NiMH batteries, i.e. you will have to replace batteries a couple of times.

4

Too bad this doesn’t work well with either charging or power bank use, the 5v input could have worked well (theoretically) in sinergy with a solar panel.
Still looking for an AA/AAA based dual function charger and powerbank for the emergency bag then. Any interesting options available?

5

I have this Varta solar panel/2xAA charger with USB-in and USB-output. I never used or tested it much, so I do not know the performance other than that it works and that the solar panels are small so it will not charge very fast on them, it charges fine on the USB-in btw.

random link: http://www.amazon.co.uk/Varta-Charger-including-Rechargeable-Batteries/dp/B002GXGQ8O

6

Well that’s actually nice, thank you! Any clue on USB out current?
I guestimated charge current on USB input to a mere 150mA based on the statement of the only reviewer that it takes 14hours (!!) for the charge to complete. Is that correct?
I wonder if this charger is a smart current-sensing one or a dumb time-based one, the former would make possible to charge AAAs too with AAA-to-AA adapters, since it doesn’t natively support AAA format.
18hours (again, stated by reviewer) in sun to charge 2pcs of AA is really a lot of time, making it unpractical in reality.

7

I have this charger for two years now, but since it is still a relevant charger because it is still for sale, I could send it to HKJ if he would be interested testing it?