Desert_AIP
New Member
- Joined
- Apr 5, 2020
- Messages
- 67
I have an all electric house.
Several years ago I built a UPS for my refrigerator with a Cotek 24V inverter and charger. I used several relays directing the output so it would maintain the batteries when on grid power then auto failover to the inverter when there was a power outage. It provided about 24 hours of backup, and had an input for a generator to refresh the batteries.
The goal was to keep the refrigerator running if there was an outage while we were away, and to be able to run the refrigerator at night during an extended power outage so we didn't have to keep the backup generator running all night.
I spliced a twist lock outlet and corded plug inline the refrigerator circuit.
The circuit travels from the breaker to an outlet, then the corded side connects to the wiring running to the refrigerator.
I can either plug in to the outlet, running straight off the grid, or place the UPS in between the outlet and plug and have utility power and battery backup.
I'm using twistlocks specifically so they can't be knocked loose.
It worked, but took up a lot of space, and the charger wasn't matched well to the new LiFePo4 battery I built.
The box I built was 24x24x24 on 8" casters and took up a LOT of space in the garage.
I recently replaced the contraption with a Growatt 3000. I reused the LiFePo4 battery.
The new install is a lot cleaner, takes up less room, has higher utility charging capacity, is programmable for lithium batteries, and has PV charging option. So in an emergency I can set up the panels I have and keep the fridge running indefinitely.
I was able to install it in an out of the way corner in my garage.
I also included a derived load center with separate input and output circuit protection, and have a second outlet for a small fridge in the garage.
Old version
New version
Several years ago I built a UPS for my refrigerator with a Cotek 24V inverter and charger. I used several relays directing the output so it would maintain the batteries when on grid power then auto failover to the inverter when there was a power outage. It provided about 24 hours of backup, and had an input for a generator to refresh the batteries.
The goal was to keep the refrigerator running if there was an outage while we were away, and to be able to run the refrigerator at night during an extended power outage so we didn't have to keep the backup generator running all night.
I spliced a twist lock outlet and corded plug inline the refrigerator circuit.
The circuit travels from the breaker to an outlet, then the corded side connects to the wiring running to the refrigerator.
I can either plug in to the outlet, running straight off the grid, or place the UPS in between the outlet and plug and have utility power and battery backup.
I'm using twistlocks specifically so they can't be knocked loose.
It worked, but took up a lot of space, and the charger wasn't matched well to the new LiFePo4 battery I built.
The box I built was 24x24x24 on 8" casters and took up a LOT of space in the garage.
I recently replaced the contraption with a Growatt 3000. I reused the LiFePo4 battery.
The new install is a lot cleaner, takes up less room, has higher utility charging capacity, is programmable for lithium batteries, and has PV charging option. So in an emergency I can set up the panels I have and keep the fridge running indefinitely.
I was able to install it in an out of the way corner in my garage.
I also included a derived load center with separate input and output circuit protection, and have a second outlet for a small fridge in the garage.
Old version
New version