Tronix Explorer 1200Ws
For the last couple of years I have happily used my Bowen's Esprit 500 heads in the studio but after a recent encounter with the new Gemini outdoor power pack I have been left wanting the ability to take my gear into the field well away from mains power.
It soon became apparent that it would be prohibitively expensive to re-equip with Gemini gear so I began looking for a more economical alternative. I purchased a 1000Ws inverter from Maplins with the intention of mating it to a car battery, only to discover that its modified sine wave was incapable of powering studio lighting. Looking round at pure sine wave inverters left me feeling cold, as they are not only heavier than modified sine wave inverters, but also several times the price.

After much internet searching I discovered a company in the Philippines that seemed to provide the answer. Innovatronix produces electronic scoreboards and portable power supplies for markets such as photography. Their product catalogue contains the Explorer portable power supply.
The marketing blurb suggests this pure sine wave inverter with integral battery is suitable for powering most common brands of studio lighting is smaller and lighter than a car battery alone, and most importantly, retails for an outstanding 249 USD.
I was initially quit sceptical as I could not find much information out about the explorer on photography websites, but in the end took the plunge and placed my order. As you can imagine it came as a pleasant surprise when I began to receive emails telling my order had been processed, then a day later shipped, then a further day later had cleared customs. I think it was 3 days door to door.

If the packaging and general build quality were anything to go by my fears about potentially buying cheap electronics that would kill my lights were relieved. The Explorer is built like a small tank!
After following the instructions and charging the device for a day I was eager to get out and use it. The weather was less keen however. After a week or so the weather cleared up and I got the chance to head out for a days shooting. I borrowed my dad's old Jaguar and set up by an industrial scene for some car shots. The Explorer performed faultlessly with surprisingly fast recycle times.
The following week I used the device for a wedding shoot. Once again it lived up to the marketing promises.

After several weeks with this device I find myself looking for ways to use it more and more. In conclusion I would say that for the money, this is the best possible way of shooting with studio lights out doors. In fact its the best 250 USD I have ever spent on photographic equipment.