battery usage

[bhuvaneshnick]

i have found a computer UPS battery which is giving 9 volt but only 0.5 amps.is that can be used for anyother purpose?

 

[ronsimpson]

A 9 volt battery can be used as a door stop. You could use it to power a 9V radio.
You really did not give much information.

 

[KeepItSimpleStupid]

Batteries are usually rated in mA-hrs or Amp-hours for non-doorstop use.

 

[bhuvaneshnick]

wait wait ,what is door stop use ,first.i google it but i did'nt get

 

[ronsimpson]

**broken link removed****broken link removed**

**broken link removed**

 

[bhuvaneshnick]

is it possible to use that for any projects (like lighting few leds around 20)

 

[kubeek]

is it possible to use that for any projects (like lighting few leds around 20)

twenty potatoes? Please put some more thought into you posts so that they make sense.

 

[bhuvaneshnick]

i would like to make 5*5 led display,does the battery suit for that?

 

[KeepItSimpleStupid]

LED's have various forward voltages largely dependent on color. So, if they were placed in series you have to have some voltage "left-over" for the resistor. If this was totally battery operated, then you have to have some "wiggle-room" or range that it will work. 8-12 V for instance. Each LED has a current that it operates at. Add them up.

A 12 V 0.5A battery makes little sense. A 12 V 500 mAh battery does. The model tells things about your battery. How long do you want the display to last? Drive by what?

All things change if these are "12 V" high intensity LEDs.

Your problem needs to be formulated better.

 

[Ian Rogers]

500mA is a big enough output at 9v... Each of my entire systems don't consume more than 80mA...

20 LED's around 25mA ( Quite bright ) = 500mA... Go for it...

 

[Nigel Goodwin]

A 12 V 0.5A battery makes little sense.

He said 9V - I took it to mean he's got a completely knackered battery out of an old UPS, stuck his multimeter across it on volts and got 9V (showing the battery is no good), and then stuck the meter across on amps and got 0.5A (showing the battery is even less good)

 

[bhuvaneshnick]

This is how my battery looks like ,but dead one(yet providing 9v abd 0.5A).Now say can i use that for my above need

 

[Ian Rogers]

Its knackered.... I thought it was a 9v..... try to re-charge it ( it's a lead acid battery ) or else chuck it in the bin

 

[bhuvaneshnick]

its knackered yet it giving 9v(12v before die)and 0.5A(around 9 A before die) when i recharge it fully

 

[Ian Rogers]

If it wont take a charge then it's gone I'm afraid.... If you put a load on it the voltage will drop further..

I have many of these things and I recharge them with a bog standard car charger ( on slow charge )....

 

[KeepItSimpleStupid]

It also looks like it's not a deep cycle battery, so it will die even faster.

Nigel: Missed the 9V part. You've been keeping me on my toes lately. Thanks.

 

[ronsimpson]

Put it by your door. It should keep the door open. I think 9 volts is about right for a door stop.

 

[JoeJester]

Your battery tells you it's rating ... 12V 7 A/hr.

You need to charge it at the initial charge rate to see if you can bring it back to specifications. Search for battery university and read about the care and maintenance of your battery.