UPS battery discharge rate

T

Tariqe

Well-Known Member
Joined
Mar 20, 2016
Messages
300
Reaction score
98
i have a KSTAR 1000va ups ( Two 7 amp/hour batteries ), connected a 20 watt bulb as a load, battery went from a 100 % charge to 70% within a minute and then took 2 hours and 50 minutes to reach 50 % according to the supplied monitoring software.
my question is dropping to 70% within a minute on a 20 watt load is normal, UPSILON monitoring software doe not display battery voltage.
 
Last edited:
Tariqe said:
i have a KSTAR 1000va ups ( Two 7 amp/hour batteries ), connected a 20 watt bulb as a load, battery went from a 100 % charge to 70% within a minute and then took 2 hours and 50 minutes to reach 50 % according to the supplied monitoring software.
my question is dropping to 70% within a minute on a 29 watt load is normal, UPSILON monitoring software doe not display battery voltage.
Click to expand...
I'd say its fairly normal, under load battery voltage drops, and the software uses voltage as a sign of how charged the battery is.

My mecer 2000va ups rigged with 20 x 7ah batteries instead of the factory 2 x 7ah batteries goes from 27.4v float charge to 26.2v when power trips to 24.8v 1 minute under load which reports 73% charge. this on a load of about 150w.

Just don't run below 50% charge if you can help it. else you'll start to degrade the batteries much faster.
 
yes, i don't let the battery drop below 50%, , unfortunately the supplied UPSILON software does not give you battery voltage.
 
another question, does anybody know if the two batteries on the KSTAR are hooked up in parallel or in series for a 24 volt system
 
Tariqe said:
another question, does anybody know if the two batteries on the KSTAR are hooked up in parallel or in series for a 24 volt system
Click to expand...
No idea, can't find a proper spec sheet, try using viewpower to monitor the ups as it gives battery voltage.
UPS's usually have very easily accessible batteries so they are user replaceable, you could always open it up and see. Usually just 1 screw, un-latching the cover exposing the batteries but not the electronics.
 
Tariqe said:
i have a KSTAR 1000va ups ( Two 7 amp/hour batteries ), connected a 20 watt bulb as a load, battery went from a 100 % charge to 70% within a minute and then took 2 hours and 50 minutes to reach 50 % according to the supplied monitoring software.
my question is dropping to 70% within a minute on a 20 watt load is normal, UPSILON monitoring software doe not display battery voltage.
Click to expand...

i think that indicates that the batteries are on their way out to be honest, also imo voltage is not a good indication of SOC, if you do a voltage SOC test you should let the batteries rest first
 
Tariqe said:
i have a KSTAR 1000va ups ( Two 7 amp/hour batteries ), connected a 20 watt bulb as a load, battery went from a 100 % charge to 70% within a minute and then took 2 hours and 50 minutes to reach 50 % according to the supplied monitoring software.
my question is dropping to 70% within a minute on a 20 watt load is normal, UPSILON monitoring software doe not display battery voltage.
Click to expand...
UPS battery SOC is a shaped display to predict what backup time one can expect from the unit. It does not measure available Ah from the batteries. So it's going to have limitations.
SLA batteries die even if the're not used. If your batteries are 5 years or older they are history.
My advice is when you have new batteries measure what the backup time is to keep your system running. (allow the UPS to shut down when batteries are fully discharged) Make a note of this time and you can then measure the battery condition by doing the same exerise and comparing the backup time with the benchmark when the batteries were new.
 
thanks, running a 20 watt bulb as a load, the ups took 3 hours and 7 minutes to discharge down to 50% ( according to the monitoring software ) , so I shall use that as a reference for battery life.
p.s It is a brand new unit from Takealot
 
Tariqe said:
thanks, running a 20 watt bulb as a load, the ups took 3 hours and 7 minutes to discharge down to 50% ( according to the monitoring software ) , so I shall use that as a reference for battery life.
p.s It is a brand new unit from Takealot
Click to expand...

seems about right, 2 x 7AH batteries is either 12 x 14 or 24 x 7 = 168W

Divide that by 2 = 84W
 
Tariqe said:
i have a KSTAR 1000va ups ( Two 7 amp/hour batteries ), connected a 20 watt bulb as a load, battery went from a 100 % charge to 70% within a minute and then took 2 hours and 50 minutes to reach 50 % according to the supplied monitoring software.
my question is dropping to 70% within a minute on a 20 watt load is normal, UPSILON monitoring software doe not display battery voltage.
Click to expand...

The fact that it drops down to 70% could also mean that the charger does not charge the batteries up to their full capacity.
Or the batteries are not the capacity they claim to be.
Or the software does not accurately measure the voltage under load correctly and reports the wrong capacity left
 
You must log in or register to reply here.
Back
Top
Sign up to the MyBroadband newsletter
X