How Do Solar Batteries Work?
Batteries are a key component of your solar power system—they let you use the sun’s energy even when it’s not shining. Your solar panels capture sunlight using photovoltaic (PV) cells that must be positioned for maximum exposure during the day. But capturing the sun’s energy is just the first step. How does that power become electricity for your appliances? That's where your inverter and batteries come into play.
Battery Voltage Chart
Understanding how voltage changes over time is key for managing your solar system’s performance. A battery’s voltage increases when it’s fully charged and gradually drops as it discharges. In fact, a fully charged battery actually shows a higher voltage than what’s printed on the packaging—that rating is closer to the voltage you’d see when the battery is nearly empty. Essentially, you’re getting more power than you’d expect when your battery is fully charged!
For example, if you check a 6-volt deep cycle battery voltage chart, you’ll notice the voltage steadily decreases as the battery loses charge. The rate of decline depends on the battery type and the device it’s powering. Powering a large inverter, for instance, will drain the battery faster than charging a phone.
With sealed lead acid batteries, you can expect about a 5% monthly discharge with moderate use, meaning their ability to deliver full voltage diminishes over time if not maintained properly. Be sure to refer to our deep-cycle lead-acid battery voltage chart for more details.
On the other hand, lithium-ion batteries are more durable and less sensitive—they can be safely discharged to around 30% of their capacity, while lead acid batteries should only be used down to about 50% capacity. Plus, lithium-ion batteries typically discharge at a slower rate, making them an excellent choice for long-term energy storage in your solar setup.
How Fast Do Batteries Recharge?
Now that you understand how battery charge relates to battery voltage, you might be curious about how quickly your battery recharges. If you want to achieve the highest voltage, it's essential to know when your battery is fully charged.
The battery charge chart can give you a clear picture of the recharge process. The primary factor influencing recharge speed is the sunlight your solar panels receive. Fewer sunny hours—like during cloudy or rainy days—mean slower recharging.
Another important factor is the battery’s level of depletion. If your battery is completely drained, it might take between 10 to 15 hours to recharge fully. In this case, it's best to avoid using the battery until it’s charged up again.
By keeping an eye on these factors, you can optimize your solar system's performance and ensure your batteries always deliver the power you need.
Lead Acid vs. Lithium Ion Battery
Depth of Discharge (DoD) refers to the percentage of a battery's capacity that has been used relative to its full capacity.
For lead acid batteries, it's generally recommended to use no more than about 50% of the battery's capacity to maximize its lifespan.
On the other hand, lithium-ion batteries are more robust and can typically handle a DoD of 80-90% without significantly shortening their cycle life.
A lead-acid battery features removable caps at the top, unlike a sealed lead-acid battery which doesn't have openings. The biggest difference is cost— lead-acid batteries are much more affordable, making them a popular choice. As long as your batteries and inverters are installed properly, using lead-acid batteries is safe.
Another advantage of lead-acid batteries is their deeper life cycle. You can run them to a lower state of charge without significantly degrading their overall lifespan.
However, we believe lithium-ion batteries are the best option. Although they come at a higher price, they are the most robust batteries available. You can safely discharge lithium-ion batteries down to about 30% capacity without worrying about damage, making them ideal for long-term use.
Conclusion
The article discusses the role of batteries in storing solar energy for later use and explains how solar panels, inverters, and batteries work together to power appliances. It highlights the importance of understanding battery discharge rates and provides voltage charts for batteries to illustrate voltage levels at different capacities.
Article by
