Hey everyone! I'm trying to figure out what size battery I need for a heater in my 300-gallon pond during the winter in central Florida. I plan to use a 1000-watt fish tank heater since temps can drop to around the 30s, and I also have a 24-watt motor that I want to run continuously. I currently have a 100-watt solar panel but am considering upgrading to a 200-watt panel. I expect the heater to run for about 8 hours a night. Can anyone break down what kind of battery setup I should be looking at without spending a fortune? Thanks a ton for any help!
3 Answers
You'll need a pretty hefty battery to handle that load! For 8 hours with a 1000W heater, you're looking at 8 kWh. Adding in your motor, you're probably best off with around 10 kWh of battery capacity. This usually means about 8 12V 100Ah batteries or equivalent setups. Plus, to recharge, you’ll need more solar power than just a 200W panel; I’d recommend at least 1-2 kW of solar panels to ensure you can keep your batteries topped off, especially in the winter.
Honestly, running that heater off battery power is going to be tough. You could also consider installing a buried wire instead, which might be more reliable and cheaper in the long run compared to juggling battery sizes and solar panels.
Considering you're pulling 1 kW overnight, you'll want around 500Ah of battery capacity at 24V to be safe. And remember, during winter, you need to account for cloudy days, so having around 1.2 kW of solar panels would help you catch enough sunlight to charge your batteries. If you can, think LFP batteries—those can handle deeper discharges and suit your needs in Florida's climate.
I see what you mean! That could definitely reduce all the hassle with charging and battery management, plus it might be more energy-efficient. Just making sure the heater's waterproof and buried properly could solve this whole puzzle.