Whether it's a weekend at the beach or months in the outback, a good camping battery keeps your fridge cold, your lights on and your phone charged. This guide explains which type of deep cycle battery to choose, how big it needs to be and how to keep it charged.
Why you need a deep cycle battery
A car starting battery is built to give a big burst of power for a few seconds to start the engine. It isn't designed to be drained, and running a fridge off it will wear it out quickly.
A deep cycle battery is built to give steady power for hours or days, then be recharged, over and over. That's exactly what camping needs.
Can I use a car battery for camping? Not for long. It will run things for a short time, but repeated draining will ruin it.
Types of deep cycle battery
| Type | Weight (100Ah) | Cycle life | Usable capacity | Price |
|---|---|---|---|---|
| Lithium (LiFePO4) | About 10 to 15 kg | 2,000 to 5,000+ | 80 to 100% | $$$$ |
| Gel | About 25 to 30 kg | 700 to 1,200 | About 50% | $$$ |
| AGM | About 25 to 30 kg | 500 to 1,000 | About 50% | $$ |
| Flooded lead-acid | About 25 to 30 kg | 300 to 500 | About 50% | $ |
For most campers, the choice comes down to lithium or AGM. Gel is less common for camping, and flooded batteries are too heavy and need too much upkeep for most setups.
Lithium vs AGM: which is best?
| Lithium | AGM | |
|---|---|---|
| Weight | About half | Heavier |
| Usable capacity | 80 to 100% | About 50% |
| Cycle life | 2,000 to 5,000+ | 500 to 1,000 |
| Charging speed | Fast | Moderate |
| Upfront cost | Higher | Lower |
Choose lithium if you:
- camp often or go on long trips
- run a fridge full-time
- need to save weight, for example in a camper trailer or tent setup
- want the battery to last many years.
Choose AGM if you:
- camp a few times a year
- have a simpler setup with lower power needs
- want the lowest upfront cost.
Lithium costs more to buy, but because it lasts so much longer and gives you nearly twice the usable power, it often works out cheaper over its life.
How big does your battery need to be?
Battery capacity is measured in amp-hours (Ah). To work out what you need, add up how much power your gear uses each day.
Example daily use
| Item | Average power | Hours a day | Daily use |
|---|---|---|---|
| Camping fridge | 24W | 24 | 576Wh |
| LED lights | 10W | 5 | 50Wh |
| Phone charging | 10W | 2 | 20Wh |
| Total | 646Wh (about 54Ah) |
A fridge's compressor turns on and off, so its average draw is much lower than its rating. The figure above is a typical average. Yours will depend on the fridge and how hot it is.
To turn watt-hours into amp-hours for a 12V battery, divide by 12. In this example, 646Wh ÷ 12 = about 54Ah a day.
What that means for battery size
- 100Ah lithium: about 90Ah usable, so roughly 1.5 days without any charging.
- 100Ah AGM: about 50Ah usable, so less than one day without charging.
Add about 20% extra to allow for hot weather and losses. If you're not recharging during the trip, multiply your daily use by the number of days.
A 100Ah lithium battery is a good starting point for most weekend campers, especially with solar or vehicle charging. For longer trips or more gear, look at 200Ah or more.
Keeping your battery charged
| Charging method | How it works | Best for |
|---|---|---|
| Solar panels | Charges from the sun through a solar regulator | Staying put for days |
| DC-DC charger | Charges from your vehicle while you drive | Touring and moving camp |
| Mains charger | Charges from a power point | At home or powered sites |
Many campers use a DC-DC charger with a solar input, so the battery charges while driving and while parked.
Rough solar sizing guide
| Battery size | Suggested solar panel |
|---|---|
| 50Ah | 80 to 120W |
| 100Ah | 160 to 200W |
| 200Ah | 300 to 400W |
Solar output drops a lot on cloudy days, in shade and in winter, so it's worth going a little bigger if you can.
Always use a solar regulator, and make sure every charger you use has a setting for your battery type. Lithium and AGM need different charging.
Do you need a battery box?
If your battery isn't fixed into a vehicle or caravan, a battery box is a must. A good one:
- protects the battery from dust, water and knocks
- stops the terminals being shorted
- adds handy outlets like USB, 12V sockets and Anderson plugs
- makes the battery easier to carry.
Look for a voltmeter or battery monitor, circuit breakers or fuses on the outputs, and a tough, weather-resistant build.
Troubleshooting
| Problem | What to check |
|---|---|
| Battery won't hold charge | Loose or corroded connections. Check the voltage when fully charged. The battery may be worn out if it's old. |
| Gear won't power on | Cables, fuses and circuit breakers. Make sure the battery has enough charge. |
| Solar isn't charging | Panel angle and shade, dirty panels, the regulator and all connections. |
| Battery is hot | Disconnect it and move it somewhere shaded and ventilated. Check the charger settings for overcharging. |
Looking after your camping battery
- Recharge after every trip. This is especially important for AGM batteries, which are damaged by being left flat.
- Store it properly. Keep it somewhere cool and dry and disconnected from everything. Store AGM batteries fully charged and top them up every few months. Store lithium batteries at around 50 to 60% charge.
- Check it regularly. Look for cracks, swelling or leaks, and keep the terminals clean and tight.
- Use the right charger. A smart charger set to your battery type prevents overcharging and undercharging.
Getting more from your setup
- Fit a battery monitor. It shows exactly how much power you have left and what you're using.
- Angle your solar panels. Moving portable panels to follow the sun makes a big difference.
- Use efficient gear. LED lights and an efficient fridge stretch your battery a long way.
- Allow for growth. Going slightly bigger now saves upgrading later.
Checklist before you buy
- List everything you want to power.
- Work out your daily use in watt-hours or amp-hours.
- Choose lithium or AGM based on how often you camp and your budget.
- Pick a capacity with some extra room. 100Ah is the minimum for most campers.
- Plan how you'll charge it: solar, DC-DC, mains or a mix.
- Decide whether you need a battery box.
- Check the warranty.
Quick answers
What size battery do I need for camping?
For a fridge, lights and phone charging, a 100Ah lithium battery suits most weekend trips, especially with solar or vehicle charging. Longer trips or more gear call for 200Ah or more.
How long will a 100Ah battery run a camping fridge?
A typical fridge averages around 2 amps, or about 48Ah a day. A 100Ah lithium battery will run it for about 2 days without charging. A 100Ah AGM battery will run it for about 1 day.
Is lithium better than AGM for camping?
For frequent camping, yes. It's lighter, lasts much longer and gives you more usable power. AGM is a good budget choice for occasional trips.
