Short answer: a 5-year warranty should name each component and a measurable limit: battery capacity remaining (for example at least 70–80 % of rated Wh), LED lumen maintenance, the controller and driver, the panel and the pole coating. It should state the response time, who replaces parts and what is excluded. It also changes the design: the battery must still cover the night at the end of the warranty, not only on day one.
Kenyan county tenders we reviewed ask for warranties of at least five years, and Uganda’s review of its USMID programme recommended at least three years of maintenance inside the contract. Buyers have learned that cheap lights fail after the first rainy seasons.
Key numbers
- Five years of nightly use is about 1,825 battery cycles and about 21,900 hours of LED operation at 12 hours a night.
- LiFePO4 cells are commonly rated at 2,000–6,000 cycles to 80 % of capacity, depending on cell grade and test conditions.
- LED lumen maintenance is projected under IES TM-21 from LM-80 data, and can only be projected up to six times the test duration.
1. Component by component
| Component | What the warranty should state | Evidence to ask for |
|---|---|---|
| Battery (LiFePO4) | Minimum capacity at year 5, e.g. ≥ 70–80 % of rated Wh; replacement if below | Cell datasheet with cycle life at stated depth of discharge and temperature; IEC 62619 or 62133 report |
| LED module and optics | Lumen maintenance at year 5; no failed LEDs above a stated share | LM-80 report and TM-21 projection for the LED package used |
| Controller and driver | Full replacement for failures within 5 years | Make and model; surge protection rating |
| Solar panel | Product warranty and power output warranty | Panel datasheet; IEC 61215 / 61730 reports |
| Pole and bracket | No perforating corrosion; coating to the stated standard | Galvanizing thickness record (ISO 1461) and steel certificate |
| Whole system | Lights the agreed hours at the agreed dimming profile | Energy balance and dimming profile in the offer |
2. Why the warranty changes battery size
A battery that just covers the night when new will not cover it in year five. A simple model: one cycle per night, capacity falling in a straight line to 80 % at the rated cycle count, plus about 1.5 % a year of calendar ageing in a warm climate.
| Cell cycle rating (to 80 %) | Cycle loss after 1,825 cycles | Capacity left at year 5 | Rated Wh needed for 1,000 Wh usable at year 5 |
|---|---|---|---|
| 2,000 cycles | about 18 % | about 74 % | about 1,350 Wh |
| 4,000 cycles | about 9 % | about 83 % | about 1,200 Wh |
| 6,000 cycles | about 6 % | about 86 % | about 1,160 Wh |
Our own simplified model; real fade depends on temperature, depth of discharge and charge rate. The point holds: a cheaper cell with a low cycle rating needs a bigger pack to meet the same warranty, and the price comparison should include that. Our sizing guide shows the full energy balance.
3. Exclusions to read carefully
- Theft and vandalism: always excluded. Design against them instead; see our anti-theft guide.
- Lightning and surges: often excluded. Ask for the surge protection rating and whether damage below it is covered.
- Installation errors: wrong panel orientation, shading or loose connections. Agree an installation checklist and handover record.
- Settings changed on site: a dimming profile raised after handover drains the battery faster.
- Pro-rata terms: some batteries are covered in full for two or three years and pro-rata after. Check which years are full replacement.
4. Who honours it, and how fast
For public tenders, the bidder is liable to the buyer, and the manufacturer’s warranty letter backs the bidder. Ask for:
- A manufacturer’s warranty letter naming the project, model numbers and quantities.
- A spare parts stock in the country, typically a small percentage of batteries, controllers and LED modules shipped with the lights.
- A response time for site visits and a replacement time for failed parts.
- Remote monitoring or controller data logs where available, so failures can be diagnosed without guesswork.
FAQ
Is a 5-year warranty on solar street lights realistic?
Yes, with LiFePO4 batteries of a good cycle rating, battery capacity sized for year five, and controllers with surge protection. It is not realistic for lights with lead-acid or undersized batteries.
What does a battery warranty usually guarantee?
A minimum share of rated capacity after a number of years or cycles. Make sure it is defined in watt-hours at the stated voltage, and that the test method is agreed.
Are theft and lightning covered?
Usually not. Anti-theft design and surge protection matter more than the warranty wording for these risks.
How long do LED street lights last?
Good LED luminaires are commonly rated for 50,000 hours or more to 70 % lumens, more than five years at 12 hours a night. The battery is usually the first component to need replacement.
How we help
Our offers state the battery cell type and cycle rating, the energy balance at the end of the warranty period and the warranty terms in writing, for solar street lights and LED street lights. Send us the warranty clause from your tender and we will show how our design meets it.
Sources: Kenyan county tender documents (2025–2026) as summarised in our Kenya tender checklist; Uganda MLHUD technical study on public lighting in USMID-AF (2024); IES LM-80 and TM-21 for LED lumen maintenance; LiFePO4 cycle ratings from manufacturers’ cell datasheets; IEC 62619, IEC 62133, IEC 61215 and ISO 1461. The battery fade model is our own simplified illustration. Related: spec-sheet checks, Uganda tenders.