The verdict, in one paragraph
If your display is LEDs on a timer, buy the smallest station with a real AC outlet — around 250Wh — and spend the difference on the timer. A published 100-count LED set draws 4.8W, so 500 bulbs for five hours is 120Wh a night, and a 245Wh battery covers two evenings on one charge. If there is an inflatable in the display, skip straight to 1,000Wh, because a blower motor runs continuously and surges on start.
The per-set wattage, published
These are retail electrical ratings, not estimates, and they are the entire reason this is cheap to do.
| Set | Published draw | Sets you may connect |
|---|
| 100-count clear incandescent mini | 120V, 0.34A, 40.8 W | Up to 5 (210 W cap) |
|---|
| 100-count LED mini | 120V, 0.04A, 4.8 W | Up to 43 (210 W cap) |
|---|
Note the right-hand column: both sets stop at the same 210W end-to-end cap, but the LED set reaches it after 43 strings rather than 5. That cap is a wiring limit on the string, not a limit on your battery, and it applies whether you plug into a wall or a power station. The full wattage breakdown goes through it properly.
How many evenings a battery gives you
Five hours a night, which is what a timer set to dusk-plus-five delivers. Capacity divided by nightly spend, rounded down.
| Display | Per night | 245 Wh | 1,056 Wh |
|---|
| 300 LEDs (3 sets) | 72 Wh | 3 nights | 14 nights |
|---|
| 500 LEDs (5 sets) | 120 Wh | 2 nights | 8 nights |
|---|
| 1,000 LEDs (10 sets) | 240 Wh | 1 night | 4 nights |
|---|
| 300 incandescent (3 sets) | 612 Wh | Under 1 night | 1 night |
|---|
| 500 LEDs + one inflatable blower | Roughly 400-600 Wh | Not viable | About 2 nights |
|---|
The inflatable row is the only one with a range rather than a figure, because blower wattage is almost never published on the box. Measure it with a plug-in meter before you plan around it.
Three things that go wrong
- The battery sits outside. Power stations are indoor objects. Lithium loses capacity in the cold and most units refuse to charge below freezing. Keep it in the garage and run a cord out.
- Nobody uses a timer. A display left on from dusk to dawn spends two to three times what the same display on a timer spends, for an audience of nobody.
- The inverter is left switched on. An idle inverter burns watts doing nothing. If your station lets you schedule or auto-off the AC port, use it; if not, the external timer does the same job from the other side.
Battery, or run a proper outdoor circuit?
Worth saying plainly: if you decorate the same yard every year and there is no exterior outlet, an electrician adding one weatherproof GFCI receptacle is a permanent fix and will likely cost less than the 1,000Wh station.
The battery wins in three situations: a rented property where you cannot alter the wiring, a display somewhere with no service at all — a fence line, a dock, a cabin — and a household that wanted a power station anyway and is glad of a December use for it. If you are in the last group, buy it for the outage first and let the lights be the bonus.
