Should you choose a lead acid battery for solar storage? A lead acid battery is a kind of rechargeable battery that stores electrical energy by using chemical reactions between lead, water, and sulfuric acid. The technology behind these batteries is over 160 years old, but the reason they’re still so popular is because they’re robust, reliable, and cheap to make and use.
If you’re looking to store energy produced by a solar array, lead acid batteries can be a good choice, but newer technologies may prove more convenient and compact.
How a lead acid battery works
While the chemistry of lead acid batteries is quite simple, writing out all the chemical equations can make it seem very complicated, so we’ll try to explain it without all of that.
The simplest version of a lead acid battery consists of three things:
- A metal plate made of lead and antimony with a negative charge
- A positively-charged metal plate made of lead dioxide
- A mixture of sulfuric acid and water
The negative plate is called an anode, the positive plate is called a cathode, and the water/acid mixture is called an electrolyte.
When the plates are suspended in the electrolyte mixture and connected to wires, the battery is ready to provide electricity!
As electrons flow out of the battery, the acid in the electrolyte begins to stick to the lead on the electrodes, converting their outer surfaces to lead sulfate and leaving extra hydrogen ions floating in the water.