UPS Voltage?

[BadNight]

I just bought a digital multimeter and wanted to check my battery and UPS.
When I check the voltage of my battery it gives 12.6. When I check voltage
of UPS ( not connected to the battery) it gives 9.7??? Shouldn't it be
higher than 12.6 for charging to take place or does it get higher when I
connect it to the battery?? When I check the voltage when Battery is
connected to UPS it gives 12.7 . The UPS is working fine otherwise. The
automatic charging red light is on when it should be charging and after some
time the blue light (charging full) turns on so every thing looks ok.

 

[Gerard Bok]

I just bought a digital multimeter and wanted to check my battery and UPS.
When I check the voltage of my battery it gives 12.6. When I check voltage
of UPS ( not connected to the battery) it gives 9.7??? Shouldn't it be
higher than 12.6 for charging to take place or does it get higher when I
connect it to the battery?? When I check the voltage when Battery is
connected to UPS it gives 12.7 . The UPS is working fine otherwise. The
automatic charging red light is on when it should be charging and after some
time the blue light (charging full) turns on so every thing looks ok.

You are probably looking at a smart charger.
It detects that there is no chargable battery connected, so it
doesn't charge anything.

 

[Rich Webb]

I just bought a digital multimeter and wanted to check my battery and UPS.
When I check the voltage of my battery it gives 12.6. When I check voltage
of UPS ( not connected to the battery) it gives 9.7??? Shouldn't it be
higher than 12.6 for charging to take place or does it get higher when I
connect it to the battery?? When I check the voltage when Battery is
connected to UPS it gives 12.7 . The UPS is working fine otherwise. The
automatic charging red light is on when it should be charging and after some
time the blue light (charging full) turns on so every thing looks ok.

[Follow-up set to s.e.b]

Here's a guess but perhaps you're reading the RMS voltage out of the
charger. If so, the peak voltage would be about 13.7 volts, a reasonable
value for an unregulated trickle charge.

 

[stan]

When you're testing a battery's condition with a digital meter, it's bestto
load the battery down somewhat, because (thanks to the superduper-high input
resistance of your meter) it can sometimes show a full, healthy voltage on
even a near-dead battery.

I use an old 50 watt 8 ohm resistor.

Sounds like he is connecting a DC reading meter across the output of
the charger circuit without knowing the output waveform and/or with
the battery disconnected. Doesn't mean a thing. If wishing to test the
charger alone (disconnected) could try a fairly big capacitor and try
and read the voltage; but even then may get a peak voltage; not
rectified RMS or true DC voltage!! A resistive load would be better to
get an average? Suggest a little reading about AC and DC electricity.

 

[[email protected]]

I just bought a digital multimeter and wanted to check my battery and UPS..
When I check the voltage of my battery it gives 12.6. When I check voltage
of UPS ( not connected to the battery) it gives 9.7??? Shouldn't it be
higher than 12.6 for charging to take place or does it get higher when I
connect it to the battery?? When I check the voltage when Battery is
connected to UPS it gives 12.7 . The UPS is working fine otherwise. The
automatic charging red light is on when it should be charging and after some
time the blue light (charging full) turns on so every thing looks ok.

Your UPS (Universal Power Source) is used to regulate your output
voltage so that it remains constant. It's possible that your battery
is just too weak(worn out) to uphold the 12.6 volts required to run
your unit. Batteries are a lot cheaper than the whole UPS so you might
want to weigh the cost factor in replacing the battery.

Mr. Rick

 

[1PW]

Your UPS (Universal Power Source) is used to regulate your output

^^^^^^^^^

voltage so that it remains constant. It's possible that your battery
is just too weak(worn out) to uphold the 12.6 volts required to run
your unit. Batteries are a lot cheaper than the whole UPS so you might
want to weigh the cost factor in replacing the battery.

Mr. Rick

The OP writes that the UPS is working OK. All the observations seem to
indicate a properly working UPS. If the OP tests the UPS by
interrupting the A.C. input source and the UPS properly supplies a
proper load for the approximate rated time period, then everything is OK.

Pete