Charging with 12V power supply does not work

So on the whole, the part looks so not bad. To start I got it fortunately did not have to use. Wonder, however, where you really should leave the device in the engine compartment, with the 40cm short jumper cables, plus 17cm terminals. And the cables come out in 20cm height from the device, which costs also again length.

There is even a German manual, in tiny writing. The most important thing is, however, nowhere this: how much capacity has now actually because the built-in mini battery ?? 10Ah? 15Ah? 20Ah?

For the 4 built-in lamps low-power LEDs would have been useful, very practical for campers, but there are only traditional soffits bulbs in it ("Light 3W" - is the combined per lamp or both?) The bottom two areas under permanent light, and since Ran to get to the screws. Perhaps we could replace itself by LED soffits, but I have not tried.

The charging status is indicated only about 3 colorful LEDs: green-yellow-red
For that I would have much rather beside the much more detailed analog display, but unfortunately only for the air pressure as is (which I probably eh never need, and the thing is hellishly loud, you get a heart attack if you accidentally wrong switch pressed).

In the lower part, with opening flap on the rear, is a large compartment, since 2 cable including power supply, the air hose from the compressor and the instructions are in it. The battery must be behind quite small ...

TECHNICAL SPECIFICATIONS:
Sealed Lead-Acid Battery (sealed lead acid battery)
Peak power 900A
Input 12V, 0.5 amps (The only entrance is the jack at the front)
Output 12V, 6A max (= max 80W connect consumers nix hairdryer or disk fan)
Compressor max 17bar, max 10 min
Light 3W
Fuse 15W (replaceable)
Weight 5.2kg

CHARGING IN AUTO:
can the unit on the one hand through a cable that comes in the car cigarette lighter. It is acc. To instructions but forbidden while the store to go by car. To allow a car to idle for an extended period, however, is also prohibited for all I know, and that law, at least in Germany. So this "opportunity charging" is more of a joke or what?

Charging at 220V:
Or on the other hand is charging at a normal 220V outlet, a small, commercially available 12V power supply. Supposedly ...
From battery charger nothing stands on it, only "AC / DC adapter, 12V, 500mA". This part leads me to 2 points deduction because it does not really work!
When the Power Station arrived here, she was already fully charged, and is then first extended period rumgestanden unused. In between checked every now and then, what show the charge state diodes and had MONTHS green. Then it was finally yellow, and when the indicator turned red a little later, I got the unit with the supplied 12V power supply attached to the socket. That was fast roasting, and after 2-3 hours I's rather hung back, if possible, even before what happened. The state diode showed green afterwards, and only a few days, then was already yellow! So again, few hours to the socket, always totally unsure how long to stay for now plugged the bright hot thing before anything burns or explodes Has indeed determined not overcharge protection, in any case, because of what nowhere. It was then think again for a few days until the state diode was yellow again! But have to risk at any store that the hut burns down, kanns probably not be.
What a waste. After some research on the web I then learned that you should load with 14V car batteries charging current, otherwise they will not fully! Aha ... So I now had a 'great' Power Station, the only could be minimal recharge via 12v power supply, namely by Design!
Of necessity I then after some time trying to find out whether we not perhaps also a normal car battery charger could be anywhere Connect to load. And look at her, it works!
Have a supposedly extremely good (lt. Amazon Com), the CTEK MXS 5, which has a setting for large or small batteries (as is the charging current only 0.8A, so very weak). And that part indicates with diodes, which makes it just exactly at what point in the charge cycle. Is so much more secure than "no indication" at the power station itself, constantly in fear of hitting the hot mini PSU could explode or burn!
Only problem was, where tuck ?? The original power supply comes in a small jack front of the device, and the CTEK charger only has connections for a special connector or small terminals for battery terminals. In the end it was then luckily works beautifully, the small terminals easy to hang from the charger to the large terminals of the Power Station.
The charge was carried out as normal. It was not hot, not even lukewarm. The diodes of the charger have only this appears as usual, that the entrance test has been passed, so the battery is not sulfated, etc., then the normal charging diode for relatively flat batteries appeared, and then it was not believable for several hours, until the trickle charge jumped round. The Power Station was therefore really been empty, the original charger completely useless!
The whole thing is now inzw. A few weeks ago, and the state of charge is still green.