Home Alarm / UPS

[brakpanpolisie]

So as per title, I want to extend my home alarms battery lifespan with a spare UPS I have lying around.
UPS is the standard, el cheapo 850va Proline/Mecer jobbie

Now, I’ve put in a new battery in the UPS, made a multiplug with a kettle cord, plugged the alarm into the multiplug and the UPS into the wall.

Using only its battery the home alarm can do quite a few hours (exact same battery) but running on the UPS it literally runs about 5 mins, UPS dies and alarm switches to its own battery.
What gives? Why would it die in such a short time?

 

[PsyWulf]

Dead cells? Too low a load?

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[souljazk]

Specs & multimeter reading of:
Alarm battery
Replacement battery

 

[brakpanpolisie]

@PsyWulf thanks for that and I think you might be right, the alarm system is very small (probably about 5 zones) so very little power draw. Also the UPS switches off without the usual beeping etc, so might just be its drawing too little power to stay alive.
Will plug in some more stuff tonight and check it out.

@souljazk battery spec Ill just double check for both but should be 12v 7.2ah, I have no idea how to operate a multimeter lol

 

[rinners]

So as per title, I want to extend my home alarms battery lifespan with a spare UPS I have lying around.
UPS is the standard, el cheapo 850va Proline/Mecer jobbie

Now, I’ve put in a new battery in the UPS, made a multiplug with a kettle cord, plugged the alarm into the multiplug and the UPS into the wall.

Using only its battery the home alarm can do quite a few hours (exact same battery) but running on the UPS it literally runs about 5 mins, UPS dies and alarm switches to its own battery.
What gives? Why would it die in such a short time?

Using a UPS will introduce more losses. Rather take the battery out the UPS (or get a new one) and wire it the alarm battery in parallel. Unless you don't have space in the box for an extra battery?