UPS Belkin 550VA Transformer can be use as a charger in 12V70AmpHr Battery?

[jayce_sos]

Hi There!

I have here a transformer from an old UPS (Belkin 550VA), I just wondering if I can use it as a battery charger, my problem is I cannot locate the PCB connected to it(to trace the flow of AC/DC). Available information of transformer I have here are in one side there are 3 wires Blue, Brown & Red on the other side Black, Red, Brown, yellow and Blue.

It is also labeled on the top

080-48172-00
GP 0751
Class B Viking B-2
E210832

Can someone help me with this little project?

Thanks in advance!

Jayce

 

[Sceadwian]

You'll never find the DC out pins of a transformer!

 

[jayce_sos]

Thanks for the reply. Okay, so how will I know which wires are plug to AC outlet and which wires are connected to bridge rectifier?

 

[RODALCO]

You should be able to use that transformer as it was used basically as a step up transformer in the inverter.
Often there are multiple primary taps on it 110, 127, 220, 230, 240, 277 Volts.

The 12 Volt side should have thick wires and low resistance.
If those get connected to a bridge rectifier it should work as a charger ok.

Put a 200 Watt lamp in series with the mains voltage during testing. just in case there is a fault or wrong connection.

 

[jayce_sos]

Okay, rodalco I'll try to test it with 200 watt lamp. Thanks!

 

[crutschow]

If the transformer is unloaded you could use a more common 100W bulb or even smaller.

 

[awt]

Just as said by Rodalco. Let me just add to it, start testing with the lamp from red to blue with black as common. The tap at which the lamp just stop glowing is ok to be connected to mains with the black.

 

[Jackdaniel]

hi

what does "550VA" mean? What is the "VA" Rating?
Could anyone please help me?

 

[Sceadwian]

That's the wattage the UPS was rated for during usage.

 

[awt]

VA is the power rating of the transformer in voltage-ampere. This is the apparent power, transformers are always rated this way. The product of VA rating and power factor of the transformer gives you real power (in watt).

 

[Jackdaniel]

VA is the power rating of the transformer in voltage-ampere. This is the apparent power, transformers are always rated this way. The product of VA rating and power factor of the transformer gives you real power (in watt).

so does "550VA" mean that it has 550 watts or Volts output power? Sorry i am a noob

 

[awt]

so does "550VA" mean that it has 550 watts or Volts output power? Sorry i am a noob

Power factor of most transformers is between 0.8 and 0.9 so wattage is less than VA. VA is used in calculating the current rating by dividing it by its rated voltage.

 

[Reloadron]

What I believe you have is a transformer harvested from a Belkin 550 VA UPS. When we say 550 VA UPS we are looking at a bigger picture than just VA (Volts * Amps). I suggest you give this link a read for an understanding of how a VA rating applies to a UPS unit. The rating of the overall UPS is not quite what the transformer rating would be in actual watts. A typical UPS has a power factor of about .7 (70%). For example I have and use several 1500 VA UPS units. That does not mean they will support a 1500 watt load. In reality they afford a little over 1 KW of true power. The VA rating being apparent power but not true power.

Ron

 

[Jackdaniel]

thank u, so what is the VA rating for a 12V 5amps transformer?

 

[awt]

thank u, so what is the VA rating for a 12V 5amps transformer?

12V * 5A = 60VA, that is it!