why don't PSUs do this...

[jhh]

I've been thinking that a PSU shpould come with a Li-ion battery that it charges up for the first few mins, then shuts itself down before it gets too hot and then back on when the cell is almost drained, having had time to cool down again.

Not sure if this'd help cooling since it'd have to be at higher load to start with, but it could at least charge silently while the PC is turned off and act as a mini UPS. The battery could also provide power for HDDs to flush theeir cache after shutdown.

I've always thought the normal UPS method a bit stupid - mains AC copnverted to DC for cells, back to AC for a PSU which just converts straight back to DC for components! A mini, internal PSU could take up a drive bay or somthing and would be rather more efficent, converting power only once instead of back and forth 3 times!

[ChiefWeasel]

I've been thinking that a PSU shpould come with a Li-ion battery that it charges up for the first few mins, then shuts itself down before it gets too hot and then back on when the cell is almost drained, having had time to cool down again.

Charging batteries is far from efficient, and would create much larger amounts of heat in the PSU than the normal setup - not sure on exact figures but around 10% efficient?

Not sure if this'd help cooling since it'd have to be at higher load to start with, but it could at least charge silently while the PC is turned off and act as a mini UPS.

Hmmm, what happens when you want to use it continuously? The inefficiency of batteries would mean your PSU would be powered continuously at a higher power than without using batteries.

The battery could also provide power for HDDs to flush their cache after shutdown.

Wasnt aware this was a problem?? Surely it only takes a few seconds?

[jhh]

k.

I was thinking half as a usual method and half for people like me who need a UPS anyway (the wiring in my building is just shocking, no pun intended)

[jinu117]

Not a bad idea. Actually, some chargers are even more efficient. It charges in pulses (read PWM... basically same concept). Every 8 charges or so it discharges 1 pulse. This keeps temperature rise down quite a bit as well as prolonging the life of battery. (background knowledge from R/C racing stuff) Another thing I can think of is there really is no need for rapid charging. So... pulse cycle can be slower (even less heat).
Now, using the battery itself still generates heat though. (and quite a bit of it) I would reckon the size of battery that will power PSU for graceful shut down would be at least twice the size of current PSU.