I ordered the 9000 battery because it ample power with 2 USB ports offers me and it is still acceptable in terms of weight (250gr). The price of around 30.00 euros is absolutely ok. Instead of shaking (so it loads connected devices), I need him only lightly touching with a finger. I find good and better shake than stupid. Charging the battery itself, takes a looong time. If it is empty, you have to, depending on the cable and source, expect 8 to 18 hours. However, then you have to charge enough power so that about 4 to 5 times its empty Smartphone, or 12 times his headphones. Personally, I would get along approximately 1 week without power. Even hardcore users are likely to loose manage an entire weekend. The anchor Astro2 feels classy us also looks classy. Was supplied USB cable. So you can either load it yourself, or you use it to his Smartphone to charge it. Both (load and loaded) at the same time is not possible, since the electronics prevents this. Well, I find that 2 devices can be loaded simultaneously. I would have wished that there had been there a USB / 220V adapter. Either you have already such an adapter, or one is forced to charge the battery to the USB port of his laptop (up to 18 hours!). In some videos you can see that an iPhone adapter is also supplied. This was not there with me. As mentioned earlier, I would have liked and it also paid a few bucks more a little more accessories. Nevertheless, I am very satisfied and would buy this exact product again. 5 stars would have given it if more accessories would have been (except the USB cable) it.