Re: [IDEA] Poor man's UPS

[Christian Trefzer <ctrefzer@gmx.de>]

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Hi there,

On Sun, May 21, 2006 at 09:31:30PM +0200, Pau Garcia i Quiles wrote:

> [interesting idea with complex implementational problems]

I think it would be cheaper ("costs" for your solutin in terms of
required I/O power and hard disk space) to use two or more lead
batteries which are charged and discharged in a round-robin fashion,
controlled by some smart home-brew circuitry, and connect the beast to
some control/monitoring software via RS-232 ; )

The logic should at least completely drain the battery before
recharging, and maybe even do a quick-and-hot charge-discharge-charge
cycle every now and then to reduce chemical byproducts at the cathode -
or was it the anode? Well, one of them is dissolved over time, and the
other one collects some sulfate or sulfide or something. If you want it
really complicated and robust, you might want to monitor the electric
parameters of the batteries at all times, to estimate the minimum
remaining time once the power is cut. You'd then have to shut down, or
better hibernate, the system cleanly within that time frame to be safe
from data loss.

I'd love to do something like that sort of in-between the PSU for a
single machine, for this would avoid the need to go from AC to DC and
back, but lacking the electrotechnical skills I'm not self-confident
enough to try and waste my PSU. Anyway, this has gone way off-topic by
now.

Kind regards,
Chris

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