Types of Battery in Solar Setup – (Components of PV System III) SS1 Solar Photovoltaic Installation & Maintenance Lesson Note

The Two Main Battery Types

In the Nigerian market today, you will mostly find two “families” of batteries. Choosing between them is like choosing between a “manual” car and an “automatic” car.

Lead-Acid Batteries (The “Old Reliable”)

These have been around for over 100 years. They are heavy and usually come in big white or grey cases.

• Sub-types: You’ll hear of Tubular (very common for Nigerian homes) and SMF/Gel (Maintenance-free).
• Best for: People on a tight budget who don’t mind replacing them every 2–4 years.

Lithium-Ion Batteries (The “New Tech”)

This is the same technology in your smartphone, but much bigger. They are often slim, wall-mounted, and very smart.

• Best for: People who want a battery that lasts 10+ years and don’t want to worry about maintenance.

Comparing Lead-Acid and Lithium

If you are advising your parents on which one to buy, keep these differences in mind:

The “Hidden” Truth: While Lithium costs more today, it is actually cheaper in the long run because you won’t have to buy a new one every few years!

Battery Sizing (How much do you need?)

“Sizing” is just a fancy word for calculating how many batteries can carry your house “load.” We measure battery capacity in Amp-Hours (Ah).

Step 1: The Load List List what you want to use at night.

• 3 LED Bulbs (10W each) × 10 hours = 300Wh
• 1 Fan (50W) × 10 hours = 500Wh
• Total needed = 800Wh

Step 2: The Battery Math If you buy a standard 12V, 200Ah battery, it has a total capacity of:

12V×200Ah=2,400Wh

Step 3: The “Golden Rule” (Depth of Discharge) You must never use 100% of a battery’s power.

• Lead-Acid: Only use 50% (so a 2,400Wh battery only gives you 1,200Wh).
• Lithium: You can use 80-90% safely.

Caring for Your Batteries (Maintenance)

A battery is like a living thing; if you treat it badly, it will “die” early. In Nigeria, the two biggest battery killers are Heat and Neglect.

1. Water Top-up (For Tubular/Flooded): Check the water levels every month. Only use Distilled Water. Never use tap water or pure water—the minerals will “poison” the battery.
2. Keep it Cool: Don’t put batteries in a hot kitchen or a small cupboard without holes. Heat is a battery’s worst enemy.
3. Clean the Terminals: Sometimes white “crust” (corrosion) grows on the battery heads. Clean it with warm water and a toothbrush, then rub some Petroleum Jelly (Vaseline) on it to stop it from coming back.
4. Avoid “Deep Discharge”: Don’t wait for the lights to go off completely before you stop using power. If you drain a battery to 0% often, it will spoil within months.

Summary and Class Activity

Key Vocabulary

• Ah (Amp-Hour): The “tank size” of the battery.
• DoD (Depth of Discharge): How much of the “tank” you have used.
• Distilled Water: Pure water used to refill lead-acid batteries.

Class Discussion Questions

1. Your neighbor uses an electric iron on his small solar battery at night. Is this a good idea? Why?
2. Why do we say Lithium batteries are better for “space-saving” in a small apartment?