Quick answer first, because that’s what you came for.
A LiFePO4 home battery (also called LFP or lithium iron phosphate) lasts 10 to 15 years under normal use.
In cycles: 6,000 to 8,000 full charge cycles
before it drops to 80% capacity. Some brands claim 10,000.
The nuance: how long those years actually turn out depends on how often you drain it per day. Use it simply for your own solar power and you’ll hit that 10 to 15 years easily. Start energy trading on a dynamic tariff and you burn through the cycles twice as fast, landing closer to 8 years.
That’s the honest answer. Now the explanation, because in nearly every article I read one thing got conveniently skipped: the conversion to years, and the warranty limit you hit first when you trade.
I’m Fred. I’ll just do the maths for you.
What does “lifespan” actually mean for a battery?
A battery doesn’t suddenly die like a light bulb.
It slowly gets wéaker. Every time you charge and discharge it, a tiny bit wears away. That’s called degradation.
Its lifespan is officially over when the battery holds only 80% of its original capacity. They call that End of Life (EOL).
Watch that word: End of Life doesn’t mean dead.
A 10 kWh battery sitting at 80% still delivers 8 kWh. That works fine. You just have a bit less buffer. More on that later, because everyone forgets to mention it.
Lifespan is measured in two ways. Remember these two, because they decide everything:
- Cycle life: how many times you can charge and discharge it.
- Calendar life: how many years it simply ages, whether you use it or not.
Whichever runs out first decides how long your battery lasts. Simple.
How many cycles does a LiFePO4 home battery get?
One cycle = one full charge and full discharge. Charge it halfway and drain it again, and that counts as half a cycle.
For LiFePO4 you keep seeing these numbers:
| Battery type | Cycles to 80% | Chemistry |
|---|---|---|
| LiFePO4 (LFP) | 6,000 – 10,000 | lithium iron phosphate |
| NMC | 2,000 – 4,000 | nickel manganese cobalt |
| Lead-acid (old) | 500 – 1,500 | lead |
So LFP is the marathon runner of the bunch. That’s why this chemistry now sits in virtually every serious home battery you can buy.
My down-to-earth note: that 10,000 comes from the glossiest brochure, measured in a lab at a neat 25 degrees with a gentle charge profile. Out on your shed wall through a cold winter and a hot summer, you won’t hit that one to one.
Do your mental maths with 6,000 to 8,000 cycles. Then you’re on the safe side and you won’t end up disappointed.
The maths: converting cycles to years
This is the part most articles skip or half-do. And it’s exactly what you want to know.
The formula is dead simple:
number of cycles ÷ cycles per year = lifespan in years
The only thing you need to know: how often do you drain that battery per day? That varies hugely by use. I’ve broken it down for you.
| Usage profile | Cycles per day | Cycles per year | Lifespan at 7,000 cycles |
|---|---|---|---|
| Light (only topping up in the evening) | 0.7 | ~250 | ~28 years (calendar wins) |
| Normal solar self-consumption | 1.0 | ~350 | ~20 years (calendar wins) |
| Intensive self-consumption | 1.3 | ~475 | ~15 years |
| Energy trading, dynamic tariff | 2.0 | ~730 | ~9.5 years |
| Aggressive trading | 2.5 | ~900 | ~7.8 years |
See what happens?
With normal use for your own solar power, you almost never reach the cycles. Then your calendar life runs out first: the battery has simply grown old, usually around 15 years, while you still have cycles to spare.
But the moment you start trading, you run 2 cycles a day or more. Then those 7,000 cycles are suddenly gone in 8 to 9 years. Cycle life then beats the calendar.
That’s the crux. Trading brings in money, but your battery wears out twice as fast. That’s fine, just factor it into your payback time.
What is calendar life and why does it count?
Even if you barely use your battery, it ages.
The chemistry in the cells slowly becomes less active, purely from the passage of time. This is called calendar degradation. For LFP we’re talking about roughly 10 to 20 years before the calendar squeezes things off.
In practice this means: leaving a battery sitting full and doing nothing is not a clever piggy bank. It wears out anyway.
And that’s exactly why the maths above matters so much. With light use, the table shows “28 years at 7,000 cycles”, but you’ll never reach that. The calendar cuts it off somewhere around year 15 to 18. The lower of the two always wins.
Degradation per year: how does it really go?
Let me put the graph into words, since I can’t hand you a picture here.
Degradation doesn’t run neatly straight down. It goes like this:
Year 1: you lose relatively a lot, often 2 to 4%. The cells “settle in”. Don’t be alarmed, that’s normal.
Years 2 to 10: it levels off. Now you lose about 1 to 2% per year. Nice and steady.
After year 10 to 12: it can speed up a little again as the battery drops towards 80%.
Rough rule: after 10 years a well-treated LFP battery still has 80 to 90% left. That’s a solid figure.
Honest word about the brochure: manufacturers love to boast “95% after year 1”. That’s sometimes true in mild lab tests, but in a real shed with actual temperature swings it’s more realistically around 90 to 92% after that first year. Not dramatic, but good to know the brochure always shows the sunny side.
Which factors wear your battery out fastest?
Four things decide whether you land at the favourable or the unfavourable end of those ranges. I’ll list them, with what you can do about each.
1. DoD (Depth of Discharge)
DoD is how deep you drain it. Drain it right down to 0 and back to 100% every time and it wears faster than if you stay between, say, 10% and 90%.
The good news: modern LFP systems handle this themselves via the BMS (Battery Management System, the clever brain in the cabinet). It keeps a margin free at the bottom and the top that you never even see. The “10 kWh” on the sticker is usually already the usable capacity, with the margin taken off.
So you rarely need to do anything about this yourself. Nice.
2. Temperature
This is the big culprit that everyone underestimates.
LFP likes 15 to 25 degrees. Above 30 degrees the degradation speeds up sharply, by up to 20%. And below freezing it won’t charge (discharging is usually still fine).
So: don’t hang that cabinet in full sun against a south wall, and not in an uninsulated garden shed that freezes over in winter either. A garage, utility room or insulated shed is ideal. Indoors is almost always better than outdoors.
3. Charge rate (C-rate)
The C-rate says how fast you charge and discharge. 1C means fully charged in 1 hour, 0.5C in 2 hours.
Charging more gently (lower C-rate) is kinder to the cells. Most home batteries run between 0.5C and 1C, and that’s perfectly fine. Only with extremely fast trading, where you constantly push full power, does this start to bite.
4. Number of cycles per year
That one already came up in the table. The more often it’s full and empty per day, the faster you’re through your cycles. This is in your own hands, through how you use it.
LFP vs NMC: why LiFePO4 wins for the home
You’ll come across two lithium types. Here’s the difference, without a chemistry textbook.
| LFP (LiFePO4) | NMC | |
|---|---|---|
| Cycles | 6,000 – 10,000 | 2,000 – 4,000 |
| Lifespan | longer | shorter |
| Safety | very stable, doesn’t burn easily | more sensitive, higher risk |
| Energy density | a bit lower (larger cabinet) | higher (more compact) |
| Ideal for | home, fixed installation | where weight/space matters |
For a home battery that hangs on the wall and needs to last 15 years, LFP is simply the better choice. More cycles, safer, longer lifespan. That an NMC battery is a bit more compact matters not one bit at home, because you’ve got the space anyway.
That’s why virtually the whole market now runs on LFP. Rightly so.
Warranty: the three limits you have to check
Now the part where most people misjudge things. A battery warranty ends at whichever comes first of three things:
- The years are up (usually 10 years, sometimes 15).
- The cycles are used up (for example 6,000).
- The throughput in kWh has been reached.
That third one, throughput, is the silent killer almost nobody mentions. It’s the total amount of energy allowed to flow through the battery during the warranty period, in kWh or MWh.
And that’s exactly the limit an energy trader hits first. Your years are nowhere near up, but you’ve pumped so much through that your throughput is gone. Warranty over.
Look at what brands promise (these are indicative, always check the current terms when you buy):
| Brand (indicative) | Warranty years | Cycles or throughput | Retained capacity |
|---|---|---|---|
| Tesla Powerwall | 10 years | unlimited cycles | ≥70% |
| BYD | 10 years | 6,000 cycles | ~60-80% |
| Enphase IQ | 10-15 years | throughput (MWh) | ≥60% |
| SonnenBatterie | 10 years | 10,000 cycles | performance warranty |
| Average LFP brand | 10 years | 6,000-8,000 cycles | ≥80% |
What to watch when buying:
- Retained capacity: 80% is decent, 60% is thin. At 60% you’re left with a lot less usable kWh at the end of the ride.
- Cycles ór throughput: if you’re going to trade, look hard at that limit. Work out your yearly throughput and set it against the warranty.
- Calendar warranty versus cycle warranty: for self-consumption you’re mostly helped by lots of warranty years. For trading, by lots of cycles or throughput.
My tip: don’t get dazzled by “6,000 cycles!” on the front. Ask about the throughput in kWh. That’s the real ceiling under intensive use.
What happens áfter the warranty or áfter the 80%?
Here’s the good news that hardly any article tells you.
At 80% your battery isn’t broken. It still delivers 80% of its kWh, and you keep using that 80% as normal. Plenty of batteries happily carry on to 70%, 60%, sometimes lower, without any trouble.
What you lose is buffer, not function.
A 10 kWh LFP battery sitting at 78% after 12 years still gives you almost 8 kWh a day. For most households that still covers the evening just fine.
So warranty over mostly means: if it breaks, you pay for it yourself. Not: throw it away. In practice, many LFP batteries run well beyond their warranty term. Count on 15 years or more of usable life under normal use.
Practical tips to make your battery last longer
Short and concrete, the way I do it myself.
- Put it somewhere cool. 15 to 25 degrees is the sweet spot. No full sun, no frosty night. This is by far the most important thing.
- Trust the BMS. Don’t go fiddling with 0-100% charging yourself. The system already protects itself.
- Don’t leave it bolt full for months. Storing it full is stress for the cells. With normal daily use this doesn’t come up, only during long idle spells (holiday home, winter shutdown).
- Do your usage maths honestly before you start trading. More cycles means more money, but faster wear too. Weigh it up.
- When buying, pick a warranty that fits your use. Self-consumption: lots of years. Trading: lots of cycles or throughput.
No magic. Just put it somewhere cool and don’t overload it.
Frequently asked questions
How long does a LiFePO4 home battery last?
Under normal use for your own solar power, an LFP battery lasts 10 to 15 years, which comes to 6,000 to 8,000 cycles to 80% capacity. Start energy trading and it’s more like 8 to 10 years, because you run more cycles per day.
What does 80% retained capacity (End of Life) mean?
That your battery still delivers 80% of its original kWh. A 10 kWh battery then still gives 8 kWh. End of Life sounds dramatic, but the battery just keeps working, you only have a bit less buffer.
How much capacity does an LFP battery lose per year?
About 2 to 4% in the first year, then roughly 1 to 2% per year. After 10 years a well-treated LFP battery is usually still at 80 to 90%.
Does energy trading wear my battery out faster?
Yes. With trading you often run 2 cycles a day or more, against 1 for self-consumption. So you’re through your cycles twice as fast. Watch out too for the throughput limit in your warranty, which you hit first when trading.
Is LFP better than NMC for the home?
For a fixed home battery, yes. LFP gets 2 to 3 times as many cycles, is safer and lasts longer. NMC is more compact, but you don’t need that space saving at home.
What should I watch out for in the warranty?
Three things: the number of years, the number of cycles ánd the throughput in kWh. The warranty ends at whichever runs out first. Also check the retained capacity: 80% is good, 60% is on the thin side.
To wrap up: run the numbers and grab your savings
Look, an LFP home battery is a solid investment that easily lasts 10 to 15 years, provided you put it somewhere cool and don’t overload it. But the real gain lies in honestly running the numbers on your situation: how many cycles do you do, which warranty fits that, and how much do you actually save?
You don’t have to do that maths on your own. On my platform I’ve gathered everything to smash your energy costs down, from battery choice to the rest of your house:
One good round of calculations easily saves you thousands over the term. That’s an afternoon’s work that pays for itself many times over.
Regards from Fred Schouten
PS: that “10,000 cycles” from the brochure? Just do your own maths with 7,000 and put the cabinet somewhere cool. Then you’ll never end up disappointed and you might even surprise yourself pleasantly.