While I wait to see if any of the more traditional battery case vendors come out with a nexus 5 solution, I decided to buy this charger accessory in the meantime. My need for something like this is not a daily driver. It is very specific days like traveling all day in airports or an extremely long day of kids activities where I know I will not have access to a charger. I do own one of the battery backup chargers but there are some instances where that is a pain to carry outside of a bag and still have frequent access to your phone. This PowerSkin solution seemed like the best option at this point for my needs. I've received the product this morning and so far I am pleased.
They sell two different microUSB models of this accessory with the only difference being the orientation of the micro USB connector. Note that the Nexus 5 does not have a USB port oriented in the way that other LG phones do so it is actually the HTC version of this product that has the correct orientation and not the LG model. However, it turns out that this does not matter at all if you have even the thinnest case on your Nexus 5. The default tip that comes with this case is not deep enough to penetrate through even the thinnest case and make appropriate contact in the Nexus 5 USB port. You need to have an accessory flex cable in order to use this accessory on your Nexus 5. The model number for that flex cable is PN09 and you have to request it from customer service. It is kind of a pain but it is the only thing available on the market at this point. You have to disconnect the plug that comes with this charger and connect the flex cable instead. The battery is 2000 mah so it should give us a little less than twice our battery capacity on the Nexus 5.
This is a very nice looking accessory with a glossy black finish that is entirely one piece and very smooth. There is a on off button and for LED light that give you an indication of battery capacity. It is charged using a micro USB port on the side of the battery from any standard USB charger.