Powerchute battery runtime calculation

[Anonymous user]

I have a BackUPS ES550R with powerchute personal edition 2.0 installed. its configured to allow max run time and hibernate with 5 mins of battery power remaining. its hooked to a Pentium 3 1.13 Ghz, 640 megs RAM, SB live 5.1, 160 gig HD, ATI 9600 256 meg video card. a samsung 22" WS LCD and a 4 port USB hub is connected to the powered outlets, the printer and speakers are plugged into the surge only side.

when testing it (with a fully charged battery) it gives about 10 minutes run time before hibernating.

when I open powerchute, initially it said 48 minutes run time. after twice testing it till it hibernated it now says 22 mintes run time. does it recalculate after every run down?

also its been on battery for about 20 minutes now (the two ten minute runs) yet in the performance statistics it shows 1 hr 27 minutes on battery power. all other statistics are correct (shows the two intentional blackouts plus a 2 second switchover the other morning while I was there).

will the "on battery" time also adjust as it gets used?

neither of these questions are biggies (unit works fine) Im just curious.

EDIT: just found there is a separate forum for Powerchute questions. if this is in the wrong place, sorry. if a moderator could move it if needed, please do.

Message was edited by: CharBroiled

[BillP]

OK, you should be getting somewhere [near these values|http://www.apc.com/products/runtime_for_extendedruntime.cfm?upsfamily=21] for your actual runtime experiments.

[BillP]

hi

the runtime reported within powerchute is an estimate so it will change when the UPS is running on battery or when something is powered down, etc. also, right out of the box, it will also adjust. since you have used it and it has fully discharged and charged back up (a sort of calibration), this also accounts for the drop in runtime.

thus, as the battery gets used, after a while the runtime should drop as the battery nears its end of life (usually 3-5 years depending on usage). the calibrations you are doing will wear it down of course too so APC usually recommends doing a calibration maybe every 6 months to a year or so. it also calibrates of course when you have an actual outage. i realize you were just testing it out though to see what you bought.

i am not sure why the performance stats say its been on battery for 1hr 27 mins especially if the other stats are correct - reporting 2 blackouts that you did and then 1 that was brief that you witnessed. that should only go up as the battery gets used more often, it shouldnt go down. the only two things i can think of to explain this are - 1.) either its just completely wrong, 2.) we are missing something here (which I am not sure what).

has anyone else seen anything like that before?

[Anonymous user]

heres a bit more info.

this is running XP home SP3 fully updated and with all drivers the latest and greatest. powerchute has never been installed on this computer before and the install went perfect. FWIW its hooked up via USB 1.1 and the machine has a mild 13% overclock, however its been fully stable for over a year at this setting and can run prime95 and memtest for days on end with no problems. it does protein folding 24/7 (folding@home).

when I pulled the plug it went to battery, the estimated time remaining immediately went to 10 minutes, counted down to zero, hibernated and 3 minutes later the UPS went to sleep, so all went exactly as planned.

it looks like it just used its initial approximately 48 minute run time estimate and multiplied it times the 2 blackouts when it found itself waking up with an almost dead battery (16%) rather than actually counting the minutes. just guessing though.

I realize that running the battery down during testing will reduce its life a bit but Im not too worried about it, my curiosity overrides a few months less battery life 🙂 Ill probably do a few more full rundowns in the next couple weeks and let you know what it reports but after that Ill just let it do its job.

thanks for any info you can provide on this.

[Anonymous user · Accepted solution]

yup, Im pretty much right on the money there, I figure total power load is around 210-250 watts (LCD-100 watts, PC - 100-140 watts (depending on system load), USB hub with EVDO modem - 10 watts). I get 9-10 minutes actual run time before hibernation, which is right in line with the chart.

powerchute still tell me on its main screen (with AC power) that I have 22 minutes run time but as soon as I pull the plug it immediately goes to 10 minutes and counts down. it started at 48 minutes so its learning 🙂

Ill probably do another run down test this week and see if it changes the estimated run time and what it says its been on battery for.