#How much battery life do you need for college full#
To convert a battery’s expected or warranted throughput into an expected lifespan, divide the throughput (expressed in kWh) by the usable capacity of the battery to estimate how many full cycles you’ll get from your battery, and divide that number of full cycles by the number of days in the year: a 20,000 kWh throughput warranty on a 10 kWh battery means 2,000 expected cycles, or a cycle per day for 5.5 years. Cycles measure how many times you can charge and discharge a battery. Throughput lets you compare how much electricity you’ll be able to move through your battery over its lifetime. A battery’s expected throughput and cycles are like a car’s mileage warranty. However, that same battery would be able to keep 20 lightbulbs on for 2 full days (0.012 kW * 20 lightbulbs * 42 hours = 10 kWh).īattery lifetimes are measured with three different metrics: expected years of operation, expected throughput and expected cycles. If you have a 5 kW, 10 kWh battery, you can only run your AC unit for two hours (4.8 kW * 2 hours = 9.6 kWh). Think about the example above of the difference between a light bulb and an AC unit. This makes the size of a battery slightly misleading, because the length of time a battery's charge will last is directly influenced by how much power it's outputting. Conversely, if you’re only using your battery to backup a few appliances with relatively small power consumption, you can keep them running for a longer amount of time. Since electricity usage is power multiplied by time, if you are using more power, then you’ll run out of stored electricity faster. Be sure to look for the usable capacity of a battery, as that number represents the amount of stored electricity that you can actually access in a battery. As a result, a battery’s storage capacity tells you how long your battery can power parts of your home. While power is expressed in kW, battery size is expressed in kilowatt-hours (kWh), which is power multiplied by time. If you want a battery with the absolute highest safety rating possible (don’t worry, they’re all safe!), look to LFP solar batteriesĪ battery’s capacity (or size) is the amount of electricity that a battery is able to store and supply to your home.If you want a battery with the longest lifetime that you can cycle the most amount of times, look for lithium iron phosphate (LFP) batteries.If you are space constrained and want to get the most amount of storage out of the least amount of space, look for lithium-ion nickel manganese cobalt (NMC) solar batteries.If you want to get the most out of every kilowatt-hour of electricity you put into your battery, look for batteries with a higher roundtrip efficiency.If you want to run your home with your solar battery for a longer amount of time, look for a battery with a higher usable capacity.If you want to be able to power a more energy-intensive appliance (like a sump pump), look for a battery with a high instantaneous power rating.If you want to power more of your home at once, look for a solar battery with a high power rating.Here are a few of the most common decision criteria, as well as which battery specs matter most if these criteria match your situation: There are a number of different potential decision criteria and comparison points to make when evaluating your energy storage options. How to decide which battery specs matter for your needs