Bought this unit to run my Bi-PAP machine during power failure. The Bi-PAP instructions said to turn the humidifier, and the heated hose off to prolong operating time when on portable power, and I forgot. With all the heated accessories on, I still got Five hours before it was exhausted. And five hours is a good nights sleep, I expect I could have gottten eight hours easy, had I reduced the load per instructions. plus Unit can be recharged in car lighter socket. Very happy with performance. Company gives good service, second to none.