Why Solar Quotes Differ: Inverters, Batteries, Panels and Wiring Compared

Two installers can quote “a 12kVA with 15kWh” and be millions of naira apart, and both can be honest about the size. The difference is what is inside: the class of inverter, the cells in the battery, the grade of the panels, and the protection and wiring nobody sees once the job is done. Nigeria’s solar market has a quality problem, and the cheap quote is usually cheap for a reason. This guide shows what to compare on paper, so you can tell.

Inverters: the same kVA is not the same inverter

On 10 November 2026, a Deye 12kW sold for a median of ₦2.44M on Jiji and a Felicity 12kVA for ₦980,000. Both say 12 on the box. They are different kinds of machine:

What the paper shows. The Deye is a grid-interactive hybrid sealed to IP65, with three solar inputs and a 5-year warranty on European listings. The Felicity IVEM and the SRNE we sell are off-grid hybrids with two solar inputs, built to sit indoors. All three run a house; they are not the same product at different prices.

What to ask for on any inverter quote:

• The exact model number, not just brand and kVA. The model number finds the datasheet.
• The warranty in years, in writing, and who honours it in Nigeria. A warranty with no local agent is hard to use.
• kW, not only kVA. The kW figure is what it actually runs.
• Solar input: how many MPPTs and how many watts each. That decides how many panels it takes.
• Where it can be mounted. IP20 must be indoors, out of dust and damp; IP65 can go outside.

Prices for every size are in our inverter price guide.

Lithium batteries: the label says 15kWh, the cells decide

Battery prices are closer: a Deye 16kWh at a median of ₦2.45M and a Felicity 15kWh at ₦2.2M on 10 November 2026. The bigger gaps are between named brands and unbranded packs, where the same “15kWh” label can hold very different cells. Read these on the datasheet:

• Cycle life with its depth of discharge. “6,000 cycles at 90%” means something; “6,000 cycles” with no percentage does not.
• Maximum continuous discharge (the BMS). A 100A BMS gives about 5kW; a 200A BMS about 10kW. A 10kW inverter on a 100A battery trips or strains it. Our LVTopsun 16kWh is rated 200A.
• Cell brand and grade. Good packs name the cell maker and say A-grade. B-grade cells, rejected from factory lines, end up in cheap packs and lose capacity early.
• Warranty years, in writing, and whether it is limited by cycles or energy delivered.
• Voltage and communication. 51.2V LiFePO₄ for a 48V inverter, and a BMS that talks to the inverter (CAN or RS485), so the inverter charges it correctly.

Prices by size and brand are in our lithium battery price guide.

Solar panels: B-grade and relabelled panels

Two problems flood the market. B-grade panels are panels that failed the factory’s A-grade checks (cracked cells, low output, colour faults). They are sold cheaply without the manufacturer’s warranty, often in the same brand’s box. Relabelled panels carry a bigger wattage on the sticker than the panel makes, such as a 550W sold as 620W.

Checks anyone can do before paying:

• Size. A 620W Jinko Tiger Neo measures 2382 × 1134mm and weighs 32.4kg. A 550W panel of the older type is about 2.28m long. A “620W” that is 10cm short is not a 620W.
• Serial numbers. Genuine A-grade panels carry serials the manufacturer can verify. Ask for them before you pay.
• Label and datasheet agree. The model number on the back label should match a datasheet that gives the same watts, size and weight.
• Price. A branded 620W far below the typical range in our solar panel price guide is a warning, not a deal.

Wiring and protection: the part you never see

A system can use good equipment and still be dangerous or short-lived because of how it is wired. A 10kW inverter on a 48V battery draws about 200 amps from it at full load. Cables too thin for that current heat up; missing fuses mean a fault has nothing to stop it. Cutting these parts is the quickest way to make a quote cheaper.

What a proper installation includes

• A DC isolator between the panels and the inverter, so the panels can be switched off safely.
• Surge protection on the solar (DC) side and the house (AC) side. Lagos storms and grid surges kill unprotected inverters.
• A fuse or DC breaker on the battery, sized for the battery current, and battery cables sized for it too.
• Proper earthing to an earth rod, not to a water pipe or nothing.
• Genuine solar connectors (MC4) and solar cable, and cables in trunking or conduit, not loose on the roof.
• Breakers rated for DC where they carry DC. An AC breaker on a DC line may not break the current when it trips.

Comparing two quotes

Put them side by side, line by line:

• Inverter: exact model, kW, warranty years.
• Battery: kWh, cycle life with depth of discharge, BMS amps, warranty years.
• Panels: brand, model, wattage, how many, A-grade with serials.
• Protection: isolator, surge protection, battery fuse, earthing, cable sizes.
• Installation, mounting and after-sales: who comes when something fails.

A system that lasts costs more on day one. Ours list every one of these lines, and our installed prices are published in full. Send us any quote on WhatsApp and we will tell you, line by line, what is in it.