Dc ups for network equipment

Hello Everyone!
I want to make my own small UPS for my home network equipment(ADSL MODEM + WIFI ROUTER). I am a student of Engineering but not of Electronics dept:. Just have basic knowledge and I know how to make a circuit etc but can't design it. I have found much help from internet in this regard and here's the image of the circuit I found the most suitable. Please check the circuit and suggest whether it will be fine.
**broken link removed**


1. Which type of battery should I should use?
2. would It prevent overcharging ?
3. How can I make it automatically switch off when the battery is discharged due to longer power cut-offs?


Source: Case Study: UPS
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As I already said, I cannot modify the circuit a/c to the recommendations. Please suggest me the type of battery to use according to the circuit above. Sorry for the circuit is not easily readable since it doesn't contain proper symbols.

please suggest me the type of battery
and I hope this circuit will prevent overcharging. Tell me if I am wrong.

Thanks in advance

cant see the schematic well enough... cant tell where the battery is... dont know how long you want it to run or your actual power requirements... linear regulators suck to begin with...

i guess the point becomes that you did not supply any real information ... problem with net searches is that you have to ask the right questions ... the same applies, to a lesser degree, when asking real people

dan