Strange? .... and partly inexplicable!

Sangean WFR-28D 2 pieces I use for about 1 month, mostly in battery mode (4 x Ansmann NiMh battery of 10,000 mAh capacity).
My needs / desires were: FM / DAB + and WIFI receiver, and mains and battery-battery operation.
After a long search and try (formerly Medion MD86062 Internet Radio, generally not as good, also Bedienungskoncept not very good) I've been using the Sangean WFR 28D finally found the right radio. With the sound through speakers, I am very satisfied (sound much better as Medion). Here is amazed, what makes this radio sound. With eyes closed you would the housing grant twice the volume. Playback via the headphone output sounds great. Playback via LINE OUT and the stereo sounds almost fantastical.
The reception is very good (particularly DAB + and internet radio). DAB + tuner is very sensitive. Wi-Fi reception is possible in every corner (Medion MD86062 was not as sensitive). The Bedinung is very intuitive. Connecting to Wi-Fi is very straightforward (I use Fritz! Box 7390).

Negatives:
1 / the number preset number (5 buttons per area, ie 5 webtv, 5 DAB stations, 5 FM stations is far too little!). Here the double would be angberacht.
2. / FM radio without autom. Channel scan!
3. / FM reception is only durschnitlich! Other Sangean Modele did much better FM tuner on board.
4 / as the weight with batteries is quite significant, would be a carrying handle or support bracket from benefits
5. / no battery status indicator.

General:
WFR-28D is a very power HUNGRY device (which is why I use rechargeable batteries)! Term until recharging for about a week in an operation of about 1-2 hours per day.
In battery / battery various power saving modes are enabled, I've left as default. The LCD display is switched off radio dark (that does not show the time in; only the 230V power mains plug), WiFi is disabled, etc. After switching on, the radio will automatically connect to the WLAN and launches start of the stream in about 20 seconds.
The large battery make the device more difficult and in conjunction with the non-slip feet quite stable, so that one-handed operation is possible without any problems, without the device from slipping.
The monochrome amber display is not very good, the contrast is extremely viewing angle dependent and scrolling jerky.
The firmware update was easily over wireless network and must be carried out in the network operation.
The menu and menu language is "ex works" English (with the latest firmware update are different languages, including German, as menus and menu language can be selected).

Anyone registered with Frontier Silicon, can create favorite channels of his choice. The required code can be found in the Radio menu under "Help". The possibilities Webradio database of Frontier Silicon to web radio station search, to the radio-favorites management and to access the most recently heard the radio station has, I like very much, also that you have deposited in Web Web radio favorite channels at all registered web radios available ( easy synchronization).

The playback of MP3 files from the USB stick (max. 64GB) shows that Sangean here provides better solutions than many of its competitors. You navigate through the Ornderstruktur which folder and file names are advertised (some special characters also work). Then you play a file obtained successively the information from the MP3 tags using the INFO button. When the competition is here very often only 8-digit MS-DOS Shortcuts. The unit plays the files of the folder, where you can adjust Shuffle and Repeat.

In addition to the USB port for USB flash drive the unit with line-in, line-out and headphone jack offers much more than many other manufacturers.
WFR-28D also offers audio equalizer with the following fixed settings: Normal, Flat, Jazz, Rock, Film, Classical, Pop, News and flexible user-EQ.

What I find strange or inexplicable?
==============================================

1 / BATTERY OPERATION (4 piece LR20 batteries; 4 x 1.5V = 6V supply voltage)
---------------------
If the battery voltage reaches about 5V, red LED (.... and WFR-28D automatically turns full off). To continue using WFR-28D, you must change unbediengt batteries (costs money).

With total voltage 5V ARE LR20 monocells NOT YET EMPTY !!!!
og batteries with 5V voltage can continue to use eg in flashlight or other devices (NOT DISPOSE !!!)!
WFR-28D work properly ONLY from 6 to 5 volts (total only 1 V range; ie only 0.25V voltage drop per cell)!

Sangean engineers THINK ABSOLUTELY NOT !!! ÖKOLIGISCH
Actually, you can construct such radio that more battery potential / voltage is used!

ATTENTION! A corresponding slide switch inside the battery compartment of the radio must be set to "Alkaline" (the device's internal battery charger is switched off)!

2. / BATTERY OPERATION (4 pieces Ansmann NiMH batteries with 10,000 mAh capacity; 4 x 1.2V = 4.8V supply voltage)
----------------
When the battery voltage reaches about 4V, red LED (.... and WFR-28D automatically turns full off). To continue using WFR-28D, you must charge unbediengt batteries.

The battery charging function of the device is described as an "intelligent fast charger" (along with supplied plug adapter model XKD-C1600IC7.5-12W)!

Ansmann 10,000 mAh batteries are only after about 12 hours of charging FULL (green-colored LED lights up permanently)! Unfortunately, this is not particularly fast!
WFR-28D has at this time FULL AUSGESCALTET BE. The charge function is indicated by a blinking in approximately every second green color LED.

Currently The following questions remain unanswered:
- Treated "intelligent fast charger" batteries correctly and optimally?
- Guaranteed "intelligent fast charger" very long battery usage / max. Life (4 Ansmann batteries 10,000 mAh are not exactly cheap)?
- Why "intelligent fast charger" will only work if WFR-28D is turned off?

ATTENTION! A corresponding slide switch inside the battery compartment of the radio must be set to "NiMH"! Only then the batteries are charged at off SANGEAN WFR-28D through the device's internal charger.

TOTAL:
All in one, a great device that is worth every penny.
A good lot of functional radio for kitchen, balcony, bathroom, garden and go. The operation is logical. Listening to music with a variety of sources is mobile in the apartment. Accessing a DLNA server, USB, Web radio, DAB +, line-in and even FM works very well.
The Remote Control / Operation via smartfone with the Sangean app works flawlessly.

I recommend the same as the Ansmann NiMH batteries with 10,000 mAh capacity to order with.