I run solar and a lot of batteries and inverter on our tow vehicle for our rig. However, when we are travelling and end up with a quick overnight somewhere (rest area, Walmart, truck stop, etc) I didn't want to have to take the time to hook up the truck to the trailer, so I purchased a plastic tool box from Home Depot and set in a couple of ES 12-12 batteries in series, a Samlex 24 volt 300 watt pure sine wave inverter, and an inexpensive wheelchair style 5 amp 24 volt charger. The 12-12's are in a plastic box inside the toolbox, and I mounted an XLR connector port for the charging, and a 50 amp Anderson Power Pole connector for the output to the inverter. So in round numbers it's 12 amp hours at 24 volts (or 288 watts). We run laptops, charge cell phones, grind coffee, sometimes run a floor fan off of it. It's portability is a key benefit, just grab it and go. Simply plug it in to 110v when it's available. You could run your laptop under a shade tree anywhere! I don't have a picture of it, but could if you want to see it.