Batteries: The Heart of Your System

Deep cycle batteries, either solo or arranged into a “battery bank” are the center of every off-grid solar or renewable energy system. All of the electricity comes and goes from the batteries. Deep-cycle batteries are your energy storage system; they store up electrons until they’re called upon to run any load or appliance.

The size of your battery bank determines how much power you can store. A smaller battery bank will limit how long your system will run before recharging is necessary. More battery capacity will allow more days of run time before recharging, however, there are practical limits in each direction. Batteries are like the muscles of your body: They need some exercise to stay healthy but not too much or they get worn out at an early age. We’ve found it’s best to aim for three to five days’ worth of battery storage. Less than three and your system will be cycling the battery deeply too frequently, which will shorten the batteries’ life. More than five and your battery bank starts getting more expensive than a backup generator or other recharging source.