The short answer: For a typical couple with a 12V fridge, the right battery for a teardrop camper is a 120Ah LiFePO4 — about 100Ah usable, which runs a normal 30–50Ah day for two to three nights with no charging at all, and refills daily off 100W of roof solar. Overnight-only campers with no fridge drop to 60Ah; heavier touring (bigger fridge, laptops, an inverter running a kettle, week-plus off-grid) steps up to 200Ah.
Size it in one line: usable Ah = daily Wh ÷ 12 ÷ 0.9, then carry two days of that and divide by the chemistry's usable fraction (~0.9 lithium, ~0.5 AGM). Don't copy caravan advice — a 300–400Ah bank is dead weight on a light trailer. Both the Hip Summit and Hip Companion ship with a 120Ah LiFePO4 as standard.
"What size battery do I need?" is the question every teardrop buyer asks, and it's the one where the most money gets wasted. Copy a caravan forum and you'll be told 300–400Ah; copy a minimalist and you'll be told 60Ah is plenty. Both can be wrong for you, because the honest answer isn't a number — it's a short sum based on how you actually camp.
The good news: that sum takes five minutes, and this guide walks the whole thing. We'll match battery size to camping style in a single table, give you the plain amp-hour formula, work a real example that lands exactly on the standard 120Ah fitment, explain why "usable" capacity is the number that matters (and why lithium beats AGM on it), and show where solar lets you carry a smaller battery. It's the same maths behind the wider teardrop camper power system — this article just zooms in on the battery.
Jump to what you need: the size-by-camping-style table · the sizing formula · a worked example · what actually draws power · usable capacity: AGM vs lithium · where 120Ah fits & when to upgrade · how solar changes the maths · how long a battery lasts · FAQs.
The Quick Answer: Battery Size by Camping Style
Match the battery to how you camp, not to the biggest number on the shelf. The table below is the fast route: find the row that sounds like your trips, read across to the daily draw, and take the battery in the last column. Everything after it explains why each row lands where it does, so you can adjust for your own gear.
| How you camp | Typical daily draw | Usable capacity you want | Battery to buy |
|---|---|---|---|
| Overnight / weekender, no fridge (lights, phones, pump only) | 10–25Ah | ~50Ah | 60Ah LiFePO4 |
| Weekends & short trips with a 12V fridge (typical couple) | 30–50Ah | ~100Ah | 120Ah LiFePO4 — standard on both Hip campers |
| 1–2 week touring, bigger fridge, laptops, some inverter use | 50–80Ah | ~150–180Ah | 200Ah LiFePO4 |
| Full-timer / extended off-grid, inverter running hard | 80–120Ah | 200Ah+ | 200–400Ah LiFePO4 |
Two rules of thumb are hiding in that table. First, carry about two days of your daily draw as usable capacity, so one overcast day never becomes an emergency. Second, the fridge dominates — the jump from row one to row two is almost entirely "you added a 12V fridge." If you're between rows, size up: it's cheaper to buy one battery slightly larger than to replace it after your first hot week. For most Australian couples, row two — a 120Ah lithium — is genuinely the right answer, which is exactly why it's the standard fitment on both models.
How to Size It Yourself: The Amp-Hour Formula
You can turn any gear list into a battery size with one line of arithmetic. Everything in a teardrop runs off a 12V battery, and battery capacity is measured in amp-hours (Ah). Here's the whole method:
- Add up your daily watt-hours (Wh). For each device, multiply its wattage by the hours per day it runs, then total them. (Watt-hours are easier to add than amp-hours because manufacturers quote watts.)
- Convert to amp-hours drawn from the battery: usable Ah = daily Wh ÷ 12 ÷ 0.9. Dividing by 12 turns watt-hours into amp-hours at the nominal 12V; dividing by ~0.9 adds a realistic 10% for wiring resistance and inverter/charge losses.
- Multiply by days of autonomy. How many days do you want to run with no charging input? Two is the sensible default — it survives one flat, cloudy day.
- Divide by the chemistry's usable fraction to get the rated capacity to buy: about 0.9 for LiFePO4, about 0.5 for AGM. This is the step most people skip — and it's why an AGM has to be roughly twice the label size of a lithium to do the same job.
That's it. Three of those numbers (12, 0.9, and your days of autonomy) barely change, so in practice sizing a battery is really just "add up my watt-hours." The solar sizing guide uses the same watt-hour budget to size panels, so once you've done this sum you're most of the way to a whole power system.
A Worked Example (That Lands on 120Ah)
Let's run the formula for the most common teardrop setup: a couple, a 12V compressor fridge, and a normal long weekend. Here are their daily watt-hours:
| Device | Power & use | Daily energy |
|---|---|---|
| 12V compressor fridge (~40L) | ~45W, ~33% duty cycle, 24 h | ~360 Wh |
| LED lighting | ~10W for 3.5 h | ~36 Wh |
| Phones, tablet, camera charging | Evening top-ups | ~60 Wh |
| Water pump | Minutes per day | ~12 Wh |
| Ventilation fan | ~5W for a warm night | ~120 Wh |
| Total | ~588 Wh/day |
Now feed it through the formula:
- Daily draw: 588 Wh ÷ 12 ÷ 0.9 = ~54Ah/day.
- Two days of autonomy: 54 × 2 = ~109Ah usable needed.
- Rated lithium capacity: 109 ÷ 0.9 = ~121Ah → buy a 120Ah LiFePO4.
That's not a coincidence — it's why 120Ah lithium is the classic teardrop fitment and the standard on both the Hip Summit and Hip Companion. Do the same sum with an AGM and the last step divides by 0.5 instead of 0.9, giving 109 ÷ 0.5 ≈ 218Ah of AGM to match one 120Ah lithium — roughly double the label, triple the weight. Change the inputs to suit your trips (drop the fan, add a bigger fridge, want three days of buffer) and the formula moves you cleanly up or down the table.
Round up, then stop. If your sum lands at, say, 140Ah, buy the next standard size (a common step is 120Ah → 200Ah) rather than chasing an exact match — but don't keep climbing "just in case." Every extra amp-hour is weight in the nose of the trailer and dollars on the invoice. A battery you can actually refill beats a bigger one you can't.
What Actually Draws Power in a Teardrop
The fridge is the whole game. In the worked example it's over 60% of the daily energy, and unlike the lights or the pump, its draw swings wildly with conditions. Everything else is small and predictable. Knowing the rough shape of these loads lets you sanity-check your own budget:
| Load | Typical daily use | Daily draw at 12V |
|---|---|---|
| 12V compressor fridge | 24 h (compressor cycling) | 17–35Ah |
| LED lighting | 2–4 h | 2–4Ah |
| Phones, tablets, camera batteries | Evening charging | 3–6Ah |
| Water pump (pressurised) | Minutes per day | <1Ah |
| Ventilation / roof fan | Warm night | 5–15Ah |
| Device via inverter (e.g. laptop) | 1–3 h | 5–20Ah |
| Typical couple, total | 30–60Ah/day |
Notice what's not on the list: air conditioning, a microwave, a household fridge, a TV. That's the entire reason a teardrop needs a fraction of a caravan's battery — the loads are smaller, so the tank can be smaller too. If you're weighing a teardrop against a bigger rig on running costs and simplicity, our teardrop vs caravan comparison puts that difference in context, and the teardrop vs campervan guide does the same for vans.
One honest caveat on the fridge: its numbers assume a mild night. Push the ambient temperature up and the compressor runs far more of the time — a fridge drawing 25Ah on a cool coastal evening can pass 50Ah in 38°C outback heat. Size for your hottest trip, not your average one. If free-camping in remote heat is your thing, the self-contained teardrop guide ties power in with water and waste, and the state off-grid guides for Queensland and Western Australia get specific about conditions.
Why "Usable" Capacity Is the Number That Matters
A battery's label capacity and its usable capacity are two different numbers, and confusing them is the single most common sizing mistake. You can't safely drain a battery to zero: how much you can actually take out before you damage it or hit the cut-off depends entirely on the chemistry. This is where AGM and lithium diverge sharply — and why comparing them by the label on the case is meaningless.
| AGM (lead-acid) | LiFePO4 (lithium) | |
|---|---|---|
| Usable capacity per 100Ah | ~50Ah (deeper discharge shortens life) | ~80–90Ah |
| Weight per 100Ah | ~28–32 kg | ~11–13 kg |
| Cycle life | 300–500 cycles | 2,000+ cycles |
| Charge efficiency | ~85% | ~99% |
| Usable Ah per kg | ~1.6Ah/kg | ~7Ah/kg |
| Cold-weather note | Charges below freezing | BMS blocks charging near 0°C unless self-heating |
Read the top row twice. A 100Ah AGM gives you about 50Ah to camp on; a 100Ah lithium gives you 80–90Ah. So a single 120Ah lithium (~100Ah usable) genuinely out-performs a 200Ah AGM (~100Ah usable) — at roughly a third of the weight. On a camper with a 700–750 kg tare, that 40–50 kg difference isn't trivia: it's payload you get back for water, food and recovery gear, and it sits in the nose of the trailer where weight most affects your tow-ball load. Add several times the cycle life, and lithium is the right call for almost every teardrop buyer — the only real exception being charging in genuine sub-zero conditions. The full head-to-head, including that cold-weather asterisk, is in our LiFePO4 vs AGM guide.
Where the Standard 120Ah LiFePO4 Fits — and When to Upgrade
Both Hip campers ship standard with a 120Ah LiFePO4 battery, 100W of roof solar and a 2,000W pure sine wave inverter — sized deliberately for real teardrop loads rather than caravan assumptions. For the row-two camper (a couple, a 12V fridge, weekends and short trips), that's the complete answer: about 100Ah usable, two-to-three nights of buffer, and a daily solar top-up. You can see how it sits in the wider spec in what's included on both models.
You should think about upgrading — a bigger battery, more solar, or both — when:
- You run a fridge in sustained heat. Remote summer touring in the north can double the fridge's draw. More solar usually helps here as much as more battery.
- You use an inverter for cooking or work. A kettle, toaster or induction cooktop pulls big current in short bursts, and a laptop running all day adds up. Heavy inverter use is the classic reason to move to a 200Ah bank.
- You camp off-grid for a week or more in poor sun. When the panel can't keep up, the battery is doing the carrying — and a bigger buffer buys you more quiet days.
- You add power-hungry extras. A diesel heater, a second fridge, a starlink dish — each is another line in your watt-hour budget. Re-run the formula before you fit them.
The reassuring part: the standard spec is a floor, not a ceiling. Solar can be added and the battery bank sized up to suit how you camp, especially on a custom build in the 3D configurator. And a right-sized system is what makes genuinely remote trips realistic in the first place — it's the same backbone behind our off-grid solar, water and power basics. If you're still deciding whether the whole thing is worth it, the is-a-teardrop-worth-it guide and our cost-of-ownership breakdown both factor the electrical system in.
How Solar Changes the Battery Maths
Your battery only has to cover the gap between what you use and what you generate — so solar is what lets a teardrop carry a small battery and still camp for a week. Think of the battery as an overnight buffer, not a fuel tank you slowly empty over a whole trip. In steady sun, a modest battery that refills every day beats a huge battery with no way to top it up.
What a roof panel actually returns depends on season and shade far more than the wattage sticker. In decent Australian sun a 100W panel returns 30–40Ah a day — against a 30–50Ah budget, that's a near-full daily replacement. Where you camp swings it hard:
| Conditions | 100W panel returns | What it means for the battery |
|---|---|---|
| Clear summer day, northern Australia | ~35–45Ah | Covers a full day; battery just carries the night |
| Clear day, southern states, shoulder season | ~25–33Ah | Covers most loads; 120Ah easily enough |
| Clear southern winter's day | ~15–25Ah | Thin for a fridge; lean on driving-charge or a blanket |
| Overcast / heavy cloud | ~5–12Ah | Battery does the work — don't undersize it |
| Deep shade (tree canopy) | Close to nothing | Battery is your only supply until you move or add a portable panel |
The takeaway cuts both ways. In good sun, don't over-buy battery — the panel is doing most of the refilling, and a 120Ah is plenty. But in a run of overcast days or deep bush shade, the panel returns almost nothing and the battery is your whole supply, so don't undersize it either. That's the balance a right-sized system strikes. The Bureau of Meteorology publishes average daily solar-exposure data for every region if you want to check your own destinations, and our solar sizing guide works the panel side in full.
When solar alone can't keep up — southern winter, days of cloud, or heavy loads — the other refill is charging as you drive. A properly wired DC-DC charger adds roughly its amp rating for every hour of driving (a couple of highway hours can replace a full day's camp use), which is why battery, solar and driving-charge are best sized as a set. The power systems guide covers DC-DC charging in detail, and if your tow vehicle is electric, the EV towing guide explains how that changes charging.
How Long Will a Battery Actually Last Off-Grid?
Flip the sum around and you can answer the question people really mean: "how many nights can I camp without charging?" Divide the battery's usable capacity by your daily draw. The table below does it for the common lithium sizes against a normal fridge-camping day — assuming no charging input at all, which is the worst case; any solar or driving-charge extends every figure.
| Battery (LiFePO4) | Usable capacity | At 30Ah/day (light) | At 50Ah/day (typical) | At 80Ah/day (heavy) |
|---|---|---|---|---|
| 60Ah | ~50Ah | ~1.5 nights | ~1 night | <1 night |
| 120Ah (standard) | ~100Ah | ~3 nights | ~2 nights | ~1.25 nights |
| 200Ah | ~170Ah | ~5–6 nights | ~3.5 nights | ~2 nights |
| 300Ah | ~260Ah | ~8 nights | ~5 nights | ~3 nights |
Two things jump out. First, a 120Ah lithium genuinely delivers the "two to three nights, no sun" buffer that makes weekend and short-trip camping stress-free. Second, the returns from a huge battery shrink fast once you factor in that you'll almost always have some charging — which is why, for most people, spending on solar to keep a 120Ah full beats spending on a 300Ah you rarely discharge. A battery monitor (a shunt-based coulomb counter) turns all of this from guesswork into a live percentage, which is a worthwhile add on any off-grid setup because lithium's flat voltage curve makes a plain voltmeter almost useless for reading state of charge.
Frequently Asked Questions
What size battery for a teardrop camper?
For a typical couple running a 12V compressor fridge, lights, a water pump and device charging, a 120Ah LiFePO4 battery is the sweet spot. It gives about 100Ah usable, which covers a 30–50Ah day for two to three nights with no charging at all, and paired with roof solar it tops back up daily. Overnight-only campers with no fridge get by on 60Ah; heavier setups — a bigger fridge, laptops, an inverter running a kettle, week-plus off-grid stays — step up to a 200Ah bank. Sizing off caravan advice (300–400Ah) just loads a light trailer with weight and cost it never uses. Both the Hip Summit and Hip Companion ship with a 120Ah LiFePO4 as standard.
Is a 120Ah lithium battery enough for a teardrop camper?
For most couples, yes. A 120Ah LiFePO4 delivers roughly 100Ah of usable capacity — enough for two to three nights of a normal 30–50Ah day (fridge, lights, pump, phone charging) with no sun at all, and with 100W of roof solar it refills most days. It only falls short if you run heavy continuous loads such as an inverter powering a kettle or induction cooker for long stretches, a large fridge in extreme heat, or you camp off-grid for a week or more in poor sun. In those cases you step up to 200Ah or add solar rather than just buying a bigger battery.
How do I calculate the battery size I need?
Add up the watt-hours each device uses in a day (watts × hours), divide by 12 to get amp-hours, then divide by about 0.9 for wiring and conversion losses — that is your true daily draw. Multiply by the number of days you want to run without charging (two is sensible), then divide by the usable fraction of your battery chemistry — about 0.9 for LiFePO4, 0.5 for AGM. That gives the rated capacity to buy. A 588Wh day works out to roughly 121Ah of rated lithium, which is why 120Ah is the standard teardrop fitment.
How many amp-hours does a 12V camper fridge use per day?
A typical 22–45L 12V compressor fridge uses about 17–35Ah a day in mild conditions, and it is almost always the single biggest load in a teardrop. The exact figure depends heavily on ambient temperature: a fridge that sips 25Ah on a mild coastal night can push past 50Ah in 38°C outback heat, because the compressor runs far more often. Always size your battery for your hottest expected trip, not an average day.
AGM or lithium — which is better for a teardrop camper battery?
Lithium (LiFePO4) is the better fit for almost every teardrop. You can safely use about 80–90% of a lithium battery versus roughly 50% of an AGM, so a 120Ah lithium gives more real capacity than a 200Ah AGM — at less than half the weight. On a 700–750 kg camper that weight saving is payload you get back for water, food and gear, right where it helps tow-ball balance. AGM only wins on lower upfront price and the ability to charge below freezing. Over its far longer cycle life, lithium is usually cheaper per usable amp-hour.
How long will a 120Ah lithium battery last off-grid?
A 120Ah LiFePO4 offers roughly 100Ah usable. On a typical 30–50Ah day — a compressor fridge, LED lights, water pump and device charging — that is two to three nights with no charging input at all. With 100W of roof solar getting reasonable sun, the battery tops back up daily and modest loads can run more or less indefinitely. Push the loads up (bigger fridge, inverter running a kettle) and the same battery might only last a night and a half, which is when solar and a driving-day top-up matter.
Do I need a 200Ah or 300Ah battery for a teardrop camper?
Rarely. A 200Ah bank suits genuine week-plus off-grid touring, a bigger fridge and regular inverter use for cooking or work. A 300–400Ah bank is caravan-scale — sensible for a big van running air conditioning and a household fridge, but on a teardrop it is dead weight and cost you almost never discharge. Most teardrop owners are better served by a 120Ah lithium plus enough solar and driving-charge to keep it full than by a huge battery they can't refill.
Does solar mean I can use a smaller battery?
Yes, within reason. The battery only has to cover the gap between what you use and what you generate. With 100W of roof solar returning 30–40Ah on a good Australian day against a 30–50Ah budget, a 120Ah battery is really only carrying you through the night and the occasional cloudy day, not the whole trip. In steady sun a modest battery plus solar beats a huge battery with no way to refill it. The exception is deep shade or a run of overcast days, where the battery — not the panel — is doing the work, so don't undersize it either.
The Bottom Line
Sizing a teardrop battery isn't a mystery and it isn't a caravan question. Add up your daily watt-hours, run usable Ah = daily Wh ÷ 12 ÷ 0.9, carry two days of it, and divide by your chemistry's usable fraction. For most couples that lands squarely on a 120Ah LiFePO4 — about 100Ah usable, two-to-three nights of buffer, and a daily solar top-up. Go smaller only if you skip the fridge; go bigger only if you genuinely run heavy loads or long off-grid stretches. And remember the battery is half the story — it's only ever as good as your ability to refill it, so size solar and driving-charge alongside it.
Or skip the homework — it's already done. Both Hip campers arrive with a right-sized 120Ah lithium, 100W solar and 2,000W inverter system fitted as standard, sized on exactly the maths above. See current stock and pricing, build your own in 3D from $18,000, compare the field in our best teardrop campers roundup and against generic vans in Hip Summit vs other teardrops, or book a viewing in Melbourne or Perth and go through the whole power system in person. More specs and ownership answers live on our FAQ page.