Two questions, one phrasing
“How long does it last” means either how many hours will it run my things or how many years before it wears out. The answers have nothing to do with each other, so this page does both.
Runtime: hours
Usable hours = capacity in watt-hours × inverter efficiency ÷ average load in watts. Use 85% efficiency unless you have a measured figure — it is conservative for a good inverter at moderate load and generous for a cheap one running near its limit.
Worked examples at a few common loads:
| Load | Average draw | On 1,000Wh | On 2,000Wh |
|---|
| Router and modem | 20 W | 42 h | 85 h |
|---|
| LED lighting, 6 bulbs | 60 W | 14 h | 28 h |
|---|
| Refrigerator, cycling | 150 W | 5.7 h | 11.3 h |
|---|
| Laptop and monitor | 100 W | 8.5 h | 17 h |
|---|
| Furnace fan, running | 600 W | 1.4 h | 2.8 h |
|---|
| Space heater, low | 750 W | 1.1 h | 2.3 h |
|---|
Computed as capacity × 0.85 ÷ load. Appliance draws from Champion Power Equipment's published wattage chart, using the low-to-mid end of each published range where the appliance cycles rather than running continuously.
The space-heater row is the one worth staring at. A 750W heater on a 2,000Wh station gives you a little over two hours. Resistive heating is the fastest way to empty a battery there is, and it is the single most common disappointment in this category. If heat is the requirement, the answer is a generator or a fuel-burning heater, not a battery.
Lifespan: years
Lithium iron phosphate cells are rated in charge cycles, where one cycle is a full discharge and recharge. Published ratings for the units on this site run from 3,000 to 6,000 cycles.
Translate that into calendar time and the numbers stop being meaningful in the usual way. At one full cycle a week, 3,000 cycles is about 58 years. At one a month — which is closer to how an emergency unit actually gets used — it is centuries. In practice the cycle rating is not what retires the unit; calendar aging, the electronics, or you replacing it with something better will get there first.
The endpoint trap
This is the part that matters when comparing brands, and it is easy to get wrong.
A cycle rating is only meaningful with its endpoint attached — the capacity level at which the cell is considered worn out. BLUETTI publishes 3,500+ cycles to 80% for the AC180. Jackery publishes 4,000 cycles to 70% for the Explorer 1000 v2. The Jackery number is larger, but 70% is a lower bar and a cell reaches it later, so the two claims are not measuring the same thing.
We cannot tell you what the BLUETTI would rate to a 70% endpoint, because it is not published and we have not tested it. What we can tell you is that ranking these batteries by headline cycle count is comparing two different tests, and any site that does it without noting the endpoints has not read the spec sheets carefully.
What actually shortens a battery's life
- Heat. The dominant factor by a distance. A unit stored in a hot garage or left in a car in summer ages considerably faster than one kept at room temperature.
- Sitting at 100% charge. Lithium cells age fastest held full. Manufacturers commonly advise storing at around half charge for long periods — which conflicts with wanting it ready, and the honest compromise is 60–80% with a top-up every few months.
- Deep discharge and long storage at empty. Leaving a station flat for months can take a cell below the voltage the management system will recover from.
- Fast charging, mildly. Repeated maximum-rate charging generates heat and contributes. Occasional use is fine; making it the default is not.
The maintenance that matters
Set a calendar reminder every three months: top the unit up, run something off it for ten minutes, and put it back. That is the entire maintenance schedule, and it does two things — it keeps the cells in a healthy range, and it tells you the unit still works before you need it to.
Store it indoors at room temperature rather than in a garage or a shed, and at somewhere between 60% and 80% rather than full. A station that cannot be found or is flat is worth exactly nothing, which is the failure mode more common than any battery degradation. The charging guide covers the practicalities.
