Two solar yard lights can carry the same size panel on the lid and still differ by roughly ten times in stored energy, because one holds a 1.2 V cell and the other a 3.7 V cell.
A solar yard light is a small outdoor LED light with its own panel, battery and dusk sensor. Pick it by lumens for the job, battery watt-hours for the night, panel watts for the darkest month and IP rating for where it sits. It charges only weakly through window glass, and most early failures come from water, heat or an undersized panel.
This guide opens with the five parts inside a solar yard light and what window glass does to charging. It then reads a spec sheet line by line, matches lumens, panel watts and battery size to path, accent, sign and wall lights, and explains why many lights fail within a season and how to size one for December. The last part covers what a garden-product brand or landscaper sends when ordering a batch with its own panel, and brands building their own light can start from custom mini solar panels for lighting products.
What is a solar yard light, and what is inside one?
A solar yard light is a self-contained lighting system: a small solar panel charges a battery by day, and a dusk sensor switches the stored energy to an LED at night. Every solar light, from a path stake to a sign light, runs on this same loop, which is why some buyers search for it as a solar system light.
Five parts sit inside the housing, and each one shows up somewhere on the spec sheet.
- Micro solar panel. A small panel on the lid, often under 1 W, turns daylight into DC current for the battery.
- Charge IC. This small chip stops the cell from over-charging on long summer days and from deep discharge on long nights.
- Battery cell. The cell holds the energy for the night, typically a single NiMH cell in small path lights and a LiFePO4 or Li-ion cell in larger accent and sign lights.
- LED driver and LED. The driver holds the LED current steady as the cell voltage falls through the night, and the LED turns that current into light.
- Dusk sensor. Many lights have no separate photocell and read the panel voltage instead, switching the LED on once that voltage falls at dusk.
An integrated panel sits on the lid, which is tidy but puts the panel wherever the light has to be, often in the shade of the plant, wall or eave it lights. A separate panel on a longer lead can go where the sun is while the light stays where it is needed, the same logic as putting the panel where the sun is and the device where it is needed on a solar security camera. Accent, sign and area lights offer that layout more often than small path stakes.
Whichever layout a light uses, the battery does all the work after dark, and the guide to what actually powers a solar light after sunset covers that stretch.
Can solar yard lights charge through a window or glass?
A solar yard light does charge through a clear window, but slowly, so windowsill charging works for topping up a light in storage while its working position stays outdoors. The panel on the lid still makes current behind glass, only much less of it than in open sun. Three things cut the charge: the glass itself, the angle of the lid and the hours of direct sun indoors.
According to PVEducation (2026), the front surface of a silicon PV module must transmit light from 350 nm to 1200 nm with low reflection. The cover on a solar panel is chosen for that one job. Window glass is chosen for comfort and insulation, so it is tuned to a different set of priorities.
Every pane adds two more surfaces that reflect part of the incoming light before it reaches the cell, and double glazing puts four in the way. The upper part of the 350 to 1200 nm band is near-infrared, which silicon cells turn into current, and low-E coatings are designed to turn back part of that infrared. A coated window therefore typically costs the cell more charge than a single clear pane does.
Indoors the lid also sits at the wrong angle. A light standing upright on a sill points its panel at the ceiling while the sun arrives low and from the side. Walls, frames and eaves then limit direct sun to a few hours on one side of the house.
- Best indoor spot. Turn the light so the lid lies flat against clear glass in the sunniest window, with no screen or curtain in between.
- Glass to avoid. Tinted, coated or double-glazed windows give little charge, so plan on outdoor sun for any real recharge.
- Porch and greenhouse sites. A light that must live under a porch roof or inside a greenhouse needs a separate panel on a lead, mounted outside the glass where the sun reaches it.
The photo above shows that layout, with the panel on its stand on the lawn outside the greenhouse glass. For how clear, tinted and low-E panes compare, and which window directions help most, see a full breakdown of solar output behind window glass.
How do you read a solar yard light spec sheet?
A solar yard light spec sheet is read in five lines: lumens for brightness, watt-hours for the night, panel watts for recharge, the IP rating for placement and the sensor or timer mode for how the stored energy is spent. According to ENERGY STAR (2026), brightness is measured in lumens, not watts. A box that lists LED watts and no lumen figure gives the buyer no brightness number to compare.
Battery: convert mAh to Wh
The battery line is usually printed in mAh, and that figure only means something once it is multiplied by the cell voltage: Wh = mAh × V ÷ 1,000. A typical path light cell of 600 mAh at 1.2 V stores 0.72 Wh, while a 2,000 mAh lithium cell at 3.7 V stores 7.4 Wh. Across chemistries, the larger mAh figure is not always the larger store of energy, so compare the Wh figure.
Dividing the Wh figure by the LED draw in watts gives a rough runtime on a full charge. The same arithmetic runs through a small panel keeping a dusk-to-dawn light lit at anchor, a worked example of nightly Wh for a small light.
Panel watts: rated at full sun
Panel watts on the box are rated at full sun, so a 0.3 W lid panel delivers a small fraction of that on a short, overcast day. Read the panel figure as a ceiling for a clear summer noon and size for the darkest month. On larger lights with lithium cells, the charge controller between panel and cell also affects harvest, and this guide explains when an MPPT controller beats PWM on a small panel.
IP rating: where the light can sit
The two digits of an IP rating grade protection against dust and against water, so ask the supplier for its test report on the finished light. IP44 is typical on decorative lights kept off the ground. IP65 is typical on stakes and on lights in irrigated beds.
Sensor and timer modes: how the energy is spent
- Dusk-to-dawn mode: The light switches on at dusk and runs until the battery or the morning ends it.
- Dusk plus set hours: The light runs a fixed number of hours after dark, the usual mode on sign lights.
- Dim with motion boost: The light idles at low output and switches to full brightness when a sensor detects movement, which spreads the same Wh across a longer night.
A dusk-to-dawn claim on a spec sheet needs a stated month, because a clear July day and a short December day leave very different amounts of energy in the cell.
Specs to compare before you order: path, accent, sign or area light?
A solar yard light should be chosen by its job first, whether that job is marking a path, lighting a plant, lighting a sign or lighting a small area. The next check is that panel wattage and battery watt-hours sit in the same typical band as the lumens. A light with high lumens and a small battery runs at full output for only a short part of the night.
Decorative lights mark where things are, task lights let people see where they walk, and sign lights usually run on a timer for a set number of hours. Each job sets a different panel size, and a guide to small panel outlines against watts and volts shows how outline, output and voltage relate on small modules.
For scale, stock mini panel formats in the size range of a yard-light lid include a 0.33 W 2.75 V ring panel, a 0.9 W 5.5 V panel at 75 × 69.5 mm in matte PET, a 1.3 W 6 V panel at 85 × 85 mm in matte PET and a 2.3 W 5.5 V panel at 113 × 113 mm under tempered glass. These are panels, not finished lights. The ranges below are typical of consumer and commercial spec sheets, not LinkSolar data.
The table compares typical lumens, panel watts, battery size, IP rating, operating mode and panel layout for the four common yard-light jobs.
| Job | Lumens (typical) | Panel W (typical) | Battery (typical) | IP (typical) | Mode | Panel layout |
|---|---|---|---|---|---|---|
| Solar path light (stake) | 5-50 lm | 0.1-0.5 W | 1.2 V NiMH, about 0.7-1.2 Wh | IP65 | Dusk-to-dawn | Integrated lid |
| Solar spot light (accent) | 50-300 lm | 0.5-2 W | 3.2-3.7 V lithium, about 4-11 Wh | IP65 | Dusk-to-dawn or timer | Integrated, or separate on a lead |
| Yard or address sign | 100-400 lm | 1-5 W | Lithium, about 4-11 Wh | IP65 | Dusk plus set hours | Separate panel above the sign |
| Solar wall light (small area) | 300-800 lm | 3-10 W | Lithium, about 10-40 Wh | IP44 sheltered to IP65 | Dim with motion boost | Integrated or separate |
Send the job and the housing outline, and LinkSolar confirms which panel fits, starting from the stock mini panels with published electrical figures.
Why do cheap solar yard lights die in one season, and how do you size for winter?
Most solar yard lights that fail in their first year fail from water at the seams, heat trapped in a sealed lid, a clouded top surface or a panel sized for summer, and the LED itself is rarely the first part to go. Water ingress typically starts at the lid seam or around the on/off switch, then corrodes the charge IC and the cell contacts. A cell sitting under a sealed black lid all summer runs hot every afternoon and loses capacity long before winter arrives.
The top surface ages as well. Of the three common front surfaces, ETFE resists UV best, low-cost PET yellowing and clouding starts after a few outdoor seasons, and tempered glass lasts longest and resists abrasion but adds weight. Matte PET suits sheltered or cost-sensitive lights, while ETFE is the usual choice for a lid that faces open sky all year.
The last two causes are about energy. A panel sized in July leaves the light short once the days close in, and a spike light set inside a shrub ends up shaded by the plant it is meant to light. A basic solar yard light carries a lunch box of energy, not a pantry: enough for one night, never three.
Winter sizing starts with peak sun hours. According to PVEducation (2026), peak sun hours equal the average daily insolation in kWh/m² per day, because peak solar radiation is 1 kW/m². In the Northern Hemisphere December brings the fewest, and snow or fallen leaves on a lid cut into what is left.
Cold also affects the battery. For lights that stay out through frost, a LiFePO4 cell handles outdoor temperature swings, and a charge controller with low quiescent current keeps more of the stored energy for the night. See how cold weather changes a small solar system.
To size a solar yard light for winter, work from the darkest month at its site:
- Write down the hours the light must run each night in the darkest month, since worst-month sizing is what keeps a path lit in December.
- Multiply those hours by the LED watts, with 20 to 30 % added for losses, to get watt-hours per night.
- Divide the nightly watt-hours by that month's peak sun hours to get the panel watts.
- Give the battery enough capacity for 2 to 3 nights of autonomy, so one overcast day does not leave the path dark.
- Mount the panel at a 30 to 45° tilt angle above fence lines and moving shade. That angle improves winter harvest and sheds rain and snow.
Where the panel sits often matters more than how big it is. For several fixtures sharing one panel and battery, use the load-to-panel formula for multi-fixture lighting runs.
What does a solar light company send when ordering a batch with a custom panel?
A solar light company or landscaper ordering a batch of solar yard lights with its own panel sends the housing outline, the electrical target and the duty profile, and gets back a panel specification before any volume is agreed. The finished light stays with the lighting brand, and the panel arrives as a component cut and wired to fit its housing.
For an OEM yard light, the intake usually covers eight items:
- Housing outline. Send the lid or housing outline in mm, including rings, rounded corners or cut-outs.
- Electrical target. Give the target Vmp and Imp, or name the battery and charge IC the panel feeds so the voltage can be matched to them.
- Duty profile. State the hours the light must run each night and the site for the worst month, since those two figures set the panel watts.
- Front surface. Pick ETFE, PET or glass in a matte or gloss finish, based on how many seasons the lid will sit in open sun.
- Termination. Specify a bare lead, solder pads or a pre-crimped harness, with the lead length the housing needs.
- Mounting. Say whether the panel is held by an adhesive back, screws or a snap-fit in the lid.
- Print. List any logo, label text or QR and serial marking for the panel face or back.
- Batch quantity. Give the quantity per order, which sets the panel price.
A brand that already runs a stock mini panel in its prototype light can send that panel's published electrical figures, since the custom version is specified from the same numbers.
LinkSolar sources custom panels built from 3 V to 48 V through LinkSolar's partner factories, with mini formats from 0.1 W to 25 W in PET, ETFE or fibreglass lamination, and runs direct factory-side QA as a sourcing partner on the China side. The reply to a brief is a buildable specification (cell layout, target Vmp and Imp, lamination, connector) with a price at the stated quantity, and sample builds get IV checks before production. Each batch then gets one pre-shipment inspection with photo and video evidence, and panels can carry OEM marking and ship in neutral packaging to the brand's assembly line.
FAQ: solar yard lights
How long should a solar yard light stay on each night?
A solar yard light typically stays on for around 6 to 10 hours after a clear summer day, and for far fewer hours after a short, overcast winter day. When comparing two lights, check which month each runtime figure refers to, because a runtime measured in June says little about December.
Should you switch solar yard lights off or bring them in for winter?
Solar yard lights in places where snow buries the lid for weeks at a time should be switched off, charged fully and stored indoors until the snow is gone. Where winters are milder, leave them out, keep the panel clear of snow and leaves, and tilt any separate panel toward the low winter sun.
Can you replace the battery in a solar yard light?
Many solar yard lights take a standard rechargeable cell that can be replaced once it stops holding a charge. The new cell must match the original chemistry and voltage, so a slot built for a 1.2 V NiMH cell takes another 1.2 V NiMH cell and never a 3.7 V lithium cell. A higher mAh rating in the same chemistry gives a longer night only if the panel can refill it.
What is a solar yard sign light and how is it powered?
A solar yard sign light, including a solar address sign with its own house number, is a small LED light aimed at a lawn or business sign, usually on a timer that switches it off a set number of hours after dusk. It is often powered by a separate panel mounted above the sign on a short lead, so the panel sees open sky while the light head stays close to the lettering.
Next step
For a solar yard light, pick lumens for the job, watt-hours for the night and panel watts for December. Garden-product brands and installers who need the panel side of a batch can send a lighting panel enquiry with the housing outline and the load figure to request a quote from LinkSolar.