Hi all. This is my first time here. Please can you help me with the pros and cons of this idea.
I have to set up a backup for my marine aquarium. I live in a rural area and powercuts are pretty regular occurrences. Two weeks ago we were out for 19 hours and I ended up buying a generator to keep my tank alive. We're going on holiday for two weeks and I need to set something up to cover me for that period. I think something that will run for 6 - 8 hours will cover most cuts.
My idea is as follows:
I want to use a deep cycle 60Ah sealed lead acid battery as the power source. To this I want to connect a 300watt inverter. To the inverter I'll connect a 50 watt heater and two pumps (for water circulation) each of about 15 watts. So way less than the 300watts maximum continuous supply from the inverter.
To keep the battery topped up I want to connect it to a trickle charger which will run from mains (grid) power so the battery will be charging when the power is on.
Now here is a bit I'm not sure about.....I want the backup heater and pumps only to come on if the mains power goes out. Essentially a UPS. To do that I thought of building a very simple relay switch. I'd build the circuit on stripboard and put it all in a box with neat plug connectors to hook up the various inputs/outputs. Using a DPDT relay I connect the positive of the battery to the Common. Connect the Normally Closed of the relay to the positive of the inverter. Then connect an off-the shelf mains type plugin transformer that converts to 12v dc to the coil of the relay. So while there is mains power the relay will hold the circuit open and the battery will be charging. During a power outage the relay coil will not be energized and the battery circuit will close and the backup system will kick in. When power comes back the circuit opens and the backup system stops, main aquarium systems resume and the charging of the battery takes over.
Sounds OK to me....but is it?
Thanks for any help & advice
I have to set up a backup for my marine aquarium. I live in a rural area and powercuts are pretty regular occurrences. Two weeks ago we were out for 19 hours and I ended up buying a generator to keep my tank alive. We're going on holiday for two weeks and I need to set something up to cover me for that period. I think something that will run for 6 - 8 hours will cover most cuts.
My idea is as follows:
I want to use a deep cycle 60Ah sealed lead acid battery as the power source. To this I want to connect a 300watt inverter. To the inverter I'll connect a 50 watt heater and two pumps (for water circulation) each of about 15 watts. So way less than the 300watts maximum continuous supply from the inverter.
To keep the battery topped up I want to connect it to a trickle charger which will run from mains (grid) power so the battery will be charging when the power is on.
Now here is a bit I'm not sure about.....I want the backup heater and pumps only to come on if the mains power goes out. Essentially a UPS. To do that I thought of building a very simple relay switch. I'd build the circuit on stripboard and put it all in a box with neat plug connectors to hook up the various inputs/outputs. Using a DPDT relay I connect the positive of the battery to the Common. Connect the Normally Closed of the relay to the positive of the inverter. Then connect an off-the shelf mains type plugin transformer that converts to 12v dc to the coil of the relay. So while there is mains power the relay will hold the circuit open and the battery will be charging. During a power outage the relay coil will not be energized and the battery circuit will close and the backup system will kick in. When power comes back the circuit opens and the backup system stops, main aquarium systems resume and the charging of the battery takes over.
Sounds OK to me....but is it?
Thanks for any help & advice