Solar charger backup

Hello,

I have a question about the possibilites to buffer a battery in a solar project for my summerhouse.
It has the typical ciruit: A solar module, a charge controller and a lead acid battery.

Looks the schematic ok? The arduino sketch doesn’t exist at the moment but that’s not the problem (I hope so).

Connector:
Pin1 – Ground
Pin2 – Output to load
Pin3 – Input from battery
Pin4 – Input from power adapter

It simple should switch over the input from the battery to a 230V/12V adapter
when the solar charger switches off the power from the load because
of deep discharge protection of the battery.

Now it comes into my mind not to use an arduino at all and simple connect
the 12V power adapter parallel to the battery or load or the solar module.

Has someone an idea how to do this or recommendations?

Thanks,
Alex

Looks fine at a first glance - remember to site decoupling next to each relay driver as well as on the regulator. Check that 1000uF is enough to hold up your rail for the time needed to detect power outage and switch the relay.

Using the relay you can switch the mains input to the mains PSU, saving more power than if it is was permanently on and you switched the output.

Thank you MarkT.

Any suggestions how to connect a power adapter to the system without the relay?
Can I connect the adapter parallel to the battery maybe or will this cause damage?

Alex

backup.png

alx: Hello,

I have a question about the possibilites to buffer a battery in a solar project for my summerhouse. It has the typical ciruit: A solar module, a charge controller and a lead acid battery.

Looks the schematic ok? The arduino sketch doesn't exist at the moment but that's not the problem (I hope so).

Connector: Pin1 – Ground Pin2 – Output to load Pin3 – Input from battery Pin4 – Input from power adapter

It simple should switch over the input from the battery to a 230V/12V adapter when the solar charger switches off the power from the load because of deep discharge protection of the battery.

Now it comes into my mind not to use an arduino at all and simple connect the 12V power adapter parallel to the battery or load or the solar module.

Has someone an idea how to do this or recommendations?

Thanks, Alex

I used this configuration:

I followed this http://makezine.com/projects/solar-usb-charger/ to connect the solar panel using only two diodes, but instead of using a USB connector I connected it to my 4xAA battery case.

It charges my batteries while they are being used.