[Skywise]

(03-31-2015, 09:36 PM)Duffy Wrote: I'm not to bad at bench testing and elimination, but I'm far from understanding the inner workings of laptops, I was hoping you could shed some light on why a 14" Dell with a 6 cell battery can operate for 8 hours, when similar size and year models like Fujitsu or Samsung operate for 3 to 4 hours?. I don't think it's different battery tec because I have several old Toshiba laptop's here (11 to be exact, stamps isn't really my thing), all the same year and model, but with 6 different serial numbers. I've tested them all with a new internal battery, and they all operated for a period of 2 to 2.5 hours, the intriguing thing here is, when I ran them on a 153Wh external battery at 6900mAh output, only one particular S number operated for 7.5 hours before the internal kicked in, (same one's I now use for the quakes) the next best was 3.5 hours.

Short answer, there's too many factors at work and you're not truly comparing like items.

The only way to truly compare would be identical makes and models of computers and batteries. And even then you'll have differences, although it should be on the matter of minutes, not hours.

Different computers will have different power consumption.

Different batteries will have different characteristics, in spite of their labeling. Batteries wear down. It also depends on how they are charged. Different manufacturers will introduce differences even if the batteries are supposed to be the same ratings.

And on top of it, the software running on the computer will have an effect. Modern processors don't consume a fixed amount of power. It all depends on how much work they are doing. Although you are running the same programs on each, there are differences behind the scenes with the OS and anything else that may be running in the background. It may be a small difference but it can add up.

When I used to play with remote control aircraft, I used lithium polymer batteries. I have a computerized charger. I used to log the charge times and milliamp-hours used put in. The electronics in the plane could monitor power usage out. I could see the battery slowly loosing it's ability to be recharged over time as it wore out.

Hope that helped more than confused.

Brian