Solar Panel Energy

Battery 101

How many solar panels does it take to charge a  battery?

  • The answer to that question varies. It depends on how big the battery is, what kind of solar panels are being used, how much sunlight there is, and for how long the solar panels are in use.
  • There are many factors to consider when sizing your system. The size of the Battery, the amount of sunlight available for charging, if there is existing panelling on your roof. Always consult an experienced solar contractor to properly size a system for your needs.
  • The power of the sun is an amazing thing. It’s entirely free. However, you’ll have to invest some time, money, and effort if you want to use the sun’s power for your own needs.
  • Think of a battery as a small tank for storing electricity. When it comes to batteries, the more solar panels you have feeding the batteries, the faster they get charged.
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Gel Batteries

  • Gel batteries are called gel because they use silica (or sand) to turn the acid inside the battery into a thick liquid. This prevents it from spilling out and causing an electrical fire. It also helps prevent other types of corrosion that can happen when acids are allowed to dry out onto terminals or other parts of the battery. It also makes using the battery safer for people because it doesn’t cause chemical burns as normal flooded batteries do.
  • They are mostly sealed, which makes them spill-proof and leak-proof. Since they are completely sealed, they are really easy to hold. And they’ll give you more power for your Rands than any other battery you can buy.
  • The Gel Battery is a maintenance-free battery that does not require refilling with distilled water. As the name suggests, this battery uses gel internally for increased shock resistance. Operating at 13.8V, this battery has good reserve capacity and cranking amps to handle heavy loads instantaneously.
  • If kept in a charged state when unused, the common lifespan of a 12-volt Gel or AGM battery is up to six years.

Lithium-ion Batteries

  • Lithium batteries are “smart” batteries that can be charged at any point in their cycle — you won’t lose your rechargeable battery’s capacity if you charge it too soon before it’s completely drained.
  • Since many people will be using their batteries to store energy from the sun, you will want them to last a long time. Lithium-ion batteries have an estimated lifespan that is significantly longer than lead-acid batteries …. so they may be a more cost-effective and reliable solution for your home solar energy storage needs.
  • Lithium batteries are a long-lasting, efficient choice for solar system installation. Most new inverters are compatible with non-lithium batteries, which makes them versatile in off-grid solar setups.
  • When it’s time to replace your old batteries, invest in green and go for Lithium-ion (Li-ion) power.

What is the Depth of Discharge (DOD) of a battery?

  • %DOD – Depth of Discharge, is used to describe how deeply the battery is discharged. If we say a battery is 100% fully charged, it means the DOD of this battery is 0%, If we say the battery has delivered 30% of its energy, here are 70% of energy reserved, we say the DOD of this battery is 30%.
  • Higher values imply deeper discharge and shorter battery life.

Gel Batteries @ 50% DOD example

12 Volt Battery bank
Battery 200Ah
Calculation at 50% DOD
1 X 12V 200Ah Batteries in Series = 12V
200Ah x 12V = 2400W
2400W / 50% DOD = 1200W
1200W (1.2kwh) available @ 50% DOD

24 Volt Battery bank
Battery 200Ah
Calculation at 50% DOD
2 X 12V 200Ah Batteries in Series = 24V
200Ah x 24V = 4800W
4800W / 50% DOD = 4800W
2400W (2.4kwh) available @ 50% DOD

48 Volt Battery bank
Battery 200Ah
Calculation at 50% DOD
4 X 12V 200Ah Batteries in Series = 48V
200Ah x 48V = 9600W
9600W / 50% DOD = 4800W
4800W (4.8kwh) available @ 50% DOD