Can I increase UPS efficiency

[holabr]

I have a small APC UPS that uses a 7.2Ah 12 volt battery. Most of the electronics (cable modem, router, VoIP Gateway, etc,) use wall wort power supplies. It seems to me that I am loosing efficiency and up time by converting the 12VDC to 110VAC then back to DC via the wall worts. Would it be worthwhile and feasable to set up voltage regulators directly off the 12V battery to power the electronics?

 

[tpetar]

I have a small APC UPS that uses a 7.2Ah 12 volt battery. Most of the electronics (cable modem, router, VoIP Gateway, etc,) use wall wort power supplies. It seems to me that I am loosing efficiency and up time by converting the 12VDC to 110VAC then back to DC via the wall worts. Would it be worthwhile and feasable to set up voltage regulators directly off the 12V battery to power the electronics?

Yes You are correct. At first devices must be opened for rewiring to lower sider (example after trafo and rectifier). Also you have to take into account that you can not use the nominal battery voltage for voltage supply to device, voltage drop will occur due load. Example if You whant to use PC direct with batteries. PC use few voltages example 12V, 5V, 3,3V -5V -12V.
You cant use 12V lead acid battery with nominal voltage at 100% of 12,73V for 12V You cant do voltage regulation to ge constant and stabilized voltage at 12V, because that You must use two batteries in serie to get 24V and then do voltage regulation to 12V but from 24V to 12V lots of power is present as heat and waste of power. In another example there is in market shops lots of low voltage devices as CFL lamp on 12V and 24V, LED lamps, small LCD TV,....

 

[holabr]

I'm not sure I understand your response. If I have a modem that runs off a 12VDC power supply, can't I simply connect it to the 12 Volt battery in the UPS? All my devices run of 12VDC or less. I was planning to use a variable regulator on those requiring less than 12VDC to get the proper voltage. Any guess on the percentage of up time I could gain by doing this?

 

[tpetar]

I'm not sure I understand your response. If I have a modem that runs off a 12VDC power supply, can't I simply connect it to the 12 Volt battery in the UPS? All my devices run of 12VDC or less. I was planning to use a variable regulator on those requiring less than 12VDC to get the proper voltage. Any guess on the percentage of up time I could gain by doing this?

Must understand difference between nominal voltage and real voltage. Nominal is 12V for lead acid, but in practice this voltage is in range between 11,9V to 12,73V if battery on float charger 13,8V.