[Nut-upsuser] MGE Pulsar Ellipse 800 offearly or box shutdown late

[tovis]

I'm struggling to configuring nut for MGE Pulsar Ellipse 800 (at least
Ellipse 800) for two boxes - home firewall and file server. I'm using
Debian 4.0 Etch, every one of them.
I'm built (after some dangerouse experiments) a testing configuration,
where boxes are plugged to line, server playing as a master, firewall as a
slave, and UPS connected to an electric heater about 300 Wats (no
reactance).
Batteries where recently changed - two 12V - 5A/h.
Using mge-shut driver - it seem to be the best for this modell.
I experienced many problems:
  - driver not starts every time (about 2 times failed from 5 tries),
    some where I found that the solution could be a 5 time retry in the
    start script (/etc/init.d/nut);
  - if I use POLLFREQ 5 (recommended default) I have been "staled" about
    2-3 times in an hour. But on ONBATTERY situation it could could be
    more frequent!? - I think this is the core of the problem.
  - the UPS switchdown early, and after 5-10 seconds the boxes follow him:(

I'm trying to set lobatt=70, offdelay=20, ondelay=60 (10 minutes),
notification=3 - but the situation still remain, and UPS switchoff quicker
(on about 70% charge?).
I'm lower the charge, instead of 300 W I'm used about 120 W (three 40 W
lamps), the system in this case work correctly. I think my problem that
this UPS allow me shutdown as quickly as possible, no wait for "LOW
BATTERY" situation, what is set by manufacturer.
Is it possible to catch not only ONLINE, ONBATTERY and LOWBATTERY but when
battery at spcified charge (ndependently what is set in UPS)?
It seem to be much better then using some kind of timers (using
upssched.conf seem to be quite messy). I'm affraid that I'm want more then
my UPS can handle, but really it is not a big prblem (in my situation)
that staff stay to wait line, but nice shutdown is crucial!