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.
UPS Voltage?
Mar 21, 2009
10 Replies
You are probably looking at a smart charger. It detects that there is no chargable battery connected, so it doesn't charge anything.
Kind regards,
Gerard Bok
[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.
Rich Webb Norfolk, VA
...Cross posting removed... The charging voltage may not be pure steady DC. The circuitry senses the battery condition and adjusts its charging characteristic. Your meter may not be able to accurately record what's happening.
Tom
When you're testing a battery's condition with a digital meter, it's best to 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.
S.
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put
nSounds 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.
Huh?
I replied to BadNight's testing of his *BATTERY*.
Anyway, suggest using a 'scope as the much better way to test a charger output.
. e
ome
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
On 03/23/2009 10:40 AM, snipped-for-privacy@gmail.com sent:
^^^^^^^^^
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
1PW @?6A62?FEH9:DE=6o2@=]4@> [r4o7t]
I thought "UPS" (not United Postal Service...) was an abbreviation for "Uninterruptible Power System". I don't recall who or how it was I came to believe that, however. regards, Joe.
Uninterruptible Power Supply
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