Get rid of the inverter; optimize your battery's stored energy
better find means of powering your electronics with direct current (DC).
Most Electronics
device operate with direct current (DC), however because electricity from the
mains supply is in alternating current (AC) form, these devices are connected
to the mains, the device manufacturer includes a power supply circuitry to step
the mains supply (AC), down to a much more lower voltage (usually) and then
convert the stepped down AC to DC.
Inverters waste
energy when converting energy stored in batteries in DC form to AC (which most
electronics are connected to) the wasted energy in the conversion process will
better serve in giving additional operational time for your electronics.