Usually, a modem is powered using AC to DC adapter which converts 230 volts AC to 9 volts or 12 volts DC
In case of power failures modem is power using an inverter,
But an invertor usually contains a 12v lead acid batteries, which is then converted to 230 volts AC using a power electronics circuit,
But in modem DC supply is used, converting a 12v Dc supply to AC and converting back them into DC usually makes more power losses.
These power losses can be avoided by directly using the battery supply to power the modem.
Using lead-acid battery
if your modem requires 12v DC to operate, you can directly use the lead-acid battery with a 12V regulator, because usually, Lead-acid batteries output voltage is greater than 12v, you can use a regulator to get stable 12v supply to a modem.
in case if your modem requires 9v to operate you can use a 9v regulator.
********If you use Linear voltage regulators like 7809 or 7812 they produce lots of heat for a prolonged operation, you need to add a heat sink to it, this also not an efficient way to power a 9v device with a 12v battery, you can use a DC-DC buck converter, which does the same function of converting high voltage dc to a low voltage dc, which works on the principle of switching mode power supply, but these are much more power efficient than the Linear voltage regulators.******
in case if you do not have a lead- acid battery, you can also use any kind of independent of the voltage.
eg: lithium batteries
Nickel Cadmium batteries
you can make them in series to give more voltage or you can make them in parallel to make more Amp hours
but in this case, you cannot use a regulator because the required voltage is greater than the available voltage so we need to boost up the voltage to get required voltage.
There are pre-made boards available as the DC-DC boost converter to boost a lower voltage to a higher voltage.
In series the voltage of the battery increases,
in this case, you can use either a regulator or a DC-DC buck converter to achieve the required voltage,
These are some ways of powering your dc devices with you batteries,
in fact charging batteries need some special attention,
we will discuss them in the next post,
In case of power failures modem is power using an inverter,
But an invertor usually contains a 12v lead acid batteries, which is then converted to 230 volts AC using a power electronics circuit,
But in modem DC supply is used, converting a 12v Dc supply to AC and converting back them into DC usually makes more power losses.
These power losses can be avoided by directly using the battery supply to power the modem.
Using lead-acid battery
if your modem requires 12v DC to operate, you can directly use the lead-acid battery with a 12V regulator, because usually, Lead-acid batteries output voltage is greater than 12v, you can use a regulator to get stable 12v supply to a modem.
in case if your modem requires 9v to operate you can use a 9v regulator.
********If you use Linear voltage regulators like 7809 or 7812 they produce lots of heat for a prolonged operation, you need to add a heat sink to it, this also not an efficient way to power a 9v device with a 12v battery, you can use a DC-DC buck converter, which does the same function of converting high voltage dc to a low voltage dc, which works on the principle of switching mode power supply, but these are much more power efficient than the Linear voltage regulators.******
in case if you do not have a lead- acid battery, you can also use any kind of independent of the voltage.
eg: lithium batteries
Nickel Cadmium batteries
you can make them in series to give more voltage or you can make them in parallel to make more Amp hours
but in this case, you cannot use a regulator because the required voltage is greater than the available voltage so we need to boost up the voltage to get required voltage.
There are pre-made boards available as the DC-DC boost converter to boost a lower voltage to a higher voltage.
In series the voltage of the battery increases,
in this case, you can use either a regulator or a DC-DC buck converter to achieve the required voltage,
These are some ways of powering your dc devices with you batteries,
in fact charging batteries need some special attention,
we will discuss them in the next post,