DC power supply tolerance

[Takenaka]

Hi,
How about the tolerance of voltage of DC power supply?

[irads]

8-15V

[Mortimer]

Are those figures coming from the expected range coming from the supplied mains PSU, or is there are limit on the Voltage range the Fit-PC can take itself?

I would like to run a Fit-PC from a Lithium-Ion pack, but these being nominally 14.4V they are very close to the 15V given in the Fit-PC spec's. Especially when you consider that a freshly charged Li-Ion pack will be sitting at 16.5V, and only drop below 15V after being discharged by about 70%.

What sort of built in regulation is there, if any?

[irads]

There is switching regulation from 12V to 5V.
The risk in high voltage is capacitor breakdown due to overvoltage.
Seems like your battery is marginally within range, but you may use 3-cell Li-Ion to be on the safe side.

[Mortimer]

I don't really want to sacrifice the capacity. This is the largest Li-Ion pack I could find with decent capacity (6.8Ah). Also the pack has an SM bus monitor in it, which will mean we can hopefully monitor the pack status from the PC, and allow the PC to protect itself, by shutting down before the power gives out. So I'll probably put in a 12V regulator for the things that cannot tolerate the full range.

Many thanks.

[J_Werc]

I am using an 11.1V Li-Ion battery with the Fit-PC. Its over-discharge protection cut-off is at 7.2V, so under regular use it can go below the necessary 8V input for the Fit-PC. Will this damage the Fit-PC, or will it simply cut off at this power? Should I attempt to install a system input voltage monitor to automatically shut the system down at ~8V? Any suggestions on software or hardware to do this would be greatly appreciated!

[irads]

fit-PC2 will not cut-off power under 8V. As voltage decreases the efficiency of switching power supplies declines up to a point where they cannot sustain current peaks.
The manufacturer recommendation is do not go below 8V. Some devices like hard disks can be damaged by insufficient power.

[J_Werc]

Thanks for the info! I'd still like to run it on a lithium-ion battery, so I need to find some way to monitor it. I have been trying to monitor the voltage input through a program called powerTOP but I got this error message: "no acpi power estimate available". I also tried the using Intel's ACPI platform directly but still nothing happened... I'm guessing when ACPI is run on a laptop, it gets its information from some sort of voltage meter on the battery. Is there a way to get ACPI to monitor the voltage input to the fit-PC?

[irads]

No, there is no voltage metering in fit-PC2.