Arduino Project - Send SMS when main power loss

[sarilla]

Hi Experts! I need your help once more

I want to program an Arduino with a GSM module that is connected to an outlet and a backup battery.
When the main power goes off I want the Arduino to feed with the backup battery and send a SMS to my number.

So far the SMS part is more or less clear but I have a doubt with the backup battery, the more I investigate it, more confused I am (far from being an expert on electronics....)

I will appreciate your guidance on this topic!

[b707]

@sarilla

but I have a doubt with the backup battery, the more I investigate it, more confused I am (far from being an expert on electronics....)

Please show an example of your investigations which appears be a much confusing for you

[sarilla]

These for example:

5v Backup power supply circuit or design

So exactly what voltage does it mandate? Would it run on 3.6 V (minimum from three NiMH)?

Mains Failure Detector

Can I have backup power for an Arduino device?

I dont know if I'm searching with the correct keywords....

[hammy]

I can’t find it , but didn’t a similar query come up yesterday about detecting mains loss and batteries ?

Anyhow …

Easiest way to detect mains failure is to use a relay powered off the mains and use it’s contacts to detect supply loss .
Lipos are difficult to use for backup as it’s difficult to charge them whilst supplying a load ( google pass thro charger ).
Easiest is a small lead acid battery , which are cheap and very safe , connected to a constant voltage supply ( at the batteries float voltage -) and connected in turn to the Arduino, either direct or via a buck convertor to give the voltage you want.

Const voltage keeps the battery charged , no glitches on power failure as no switch over .
There are many other ways , probably worth getting some battery knowledge and how to charge them .
If you wanted to you could also monitor the battery voltage !

[lastchancename]

You’re solving two problems…

1. detect power droop
2. identify threshold, and send notification
   … shutdown, or any subsequent actions.

[sarilla]

Thanks! I need to check how to connect the battery in... ¿paralel?

anyway, i was thinking about a possible solution, what do you think? I was wondering if the relay should be open or closed....

[hammy]

Open or closed - doesn’t matter .

In parallel - I’ve only shown wot connects to wot , not the individual wires .

I think you need to look at some basic elastictrickery stuff , so you understand what you are doing and why .
Get someone to do the mains part and get that bit enclosed so you are safe if you are unsure

Good project !!