PV Gap

Rhonda Said:

I need to convert 12vdc to 12vac. I am trying to run an very small aquarium air pump. It is 60hz and 2.7 watts?

We Answered:

Why would you need 12 VAC if your motor is 12 VDC? But a DC motor doesn't have a 60 Hz specification, so which is it?

But a good inverter is 90% efficient, so that is not the problem. I suspect your battery is not big enough, although lasting a week is pretty good, why is that not good enough?

12 VAC inverters are not available off the shelf as far as I know.

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Julie Said:

Two lead/acid batteries in series don't discharge evenly?

We Answered:

The smaller battery is already ruined, you can't put batteries in series unless they're perfectly matched. When the smaller battery dies the bigger battery pushes current through it and reverse charges the smaller one.
A lot of low power gear can operate on anywhere from 10 to 32 volts now.
12.2 volts isn't fully charged on a lead acid battery. They're more like 13.2V after a charge. Your solar controller will keep about 14V to the battery while the sun is up.
The simplest POE is just feeding voltage on parallel wires. 2 for plus and two for minus.

Salvador Said:

Does voltage effect battery charging time?

We Answered:

The battery must be supplied a voltage above its terminal voltage. The voltage difference determines the current at which it is charged, and 12 volts across a 6V battery will produce too much current, possibly ruining both the battery and the charger!
The battery/ batteries should have charging voltages/ currents marked on it, or perhaps a data sheet is available with the information.??
Likewise for the solar charger.
It is OK to charge a battery at less than its maximum rate. But you must not exceed it.

Virgil Said:

Does voltage play a role in battery charging time?

We Answered:

If both of your charging sources are current limited to 1 amp both will charge you pack at that rate as long as the sources have a voltage that is a bit higher than the voltage of the pack. You charge controller might also perform the current limit function.

If the current ratings are merely the amount of current that the source can safely deliver without overheating, the 12 volt one may be overloaded if there is no means to limit the current.

Don