Illustrative runtimes for common camping equipment. Actual results vary depending on battery type, appliance efficiency and operating conditions.

As a general guide:

Again, these figures are intended as a guide rather than a guarantee, as every setup is different.

200Ah Battery Runtime Examples

A 200Ah battery is ideal for people who spend extended periods off-grid or run larger electrical systems.

Typical applications include:

• Larger caravans
• Motorhomes
• Off-grid cabins
• Solar storage systems
• Larger inverter setups

One of our preferred high-capacity options is the Remco RM12-200LFP Lithium Battery.

Lithium batteries provide more usable capacity, recharge faster and weigh significantly less than equivalent AGM batteries.

Estimated Runtime

Bigger Isn’t Always Better

Many people assume that buying the largest battery available is the safest option.

In reality, that’s often unnecessary.

Larger batteries:

• Cost more
• Weigh significantly more
• Take longer to recharge
• Require more installation space

At Battery Warehouse, we often recommend selecting a battery that comfortably meets your expected power requirements, rather than simply buying the biggest battery available.

One Large Battery or Two Smaller Batteries?

This is another common question.

Many people are surprised to learn that two medium-sized batteries can often be the better solution.

For example:

Two quality 120Ah AGM batteries may provide advantages over one very large AGM battery, including:

• Easier lifting and installation
• Better weight distribution
• More flexible installation options
• Simpler replacement if one battery eventually reaches the end of its life

For very large battery banks, many installers also choose 6V deep cycle batteries wired in series to achieve higher capacities while maintaining excellent performance.

AGM vs Lithium – Which Is Better?

There isn’t a single “best” battery.

The right choice depends on how you use it.

If you’re camping a few weekends each year, a quality AGM battery is often excellent value.

If you’re travelling regularly, living in a caravan or relying on solar power, lithium can provide significant long-term benefits.

To compare the latest options, explore our range of Lithium Batteries and Deep Cycle Batteries.

Worked Example 1 – Weekend Camping

Let’s imagine you’re heading away for two nights.

You’ll be running:

Total estimated usage: 79Ah

For this setup:

• A 120Ah AGM battery would provide a comfortable safety margin.
• An equivalent lithium battery could achieve the same result with a smaller advertised capacity because more of its stored energy is usable.

Worked Example 2 – Caravan Holiday

You’re travelling for several days and using:

• Compressor fridge
• LED lighting
• Water pump
• Diesel heater
• Phone charging
• Laptop charging

Estimated daily consumption:

Total = 125Ah per day

This is the sort of setup where a larger battery bank—or solar charging combined with lithium batteries—can make a noticeable difference to your time off-grid.

A Common Buying Mistake

One of the biggest mistakes we see is customers choosing a battery based solely on the amp hour number printed on the label.

Capacity is important, but so are:

• Battery chemistry
• Charge acceptance
• Weight
• Cycle life
• Physical dimensions
• Charging system compatibility
• Intended use

That’s why we always recommend looking at the complete picture rather than focusing on just one specification.

Still Not Sure?

If you’ve completed the calculator and you’re unsure whether a 100Ah, 120Ah or 200Ah battery is the right choice, we’re here to help.

Our experienced team can recommend a battery based on:

• Your camping style
• Your caravan or boat
• Your expected daily power consumption
• Your charging system
• Your budget

Browse our range of Deep Cycle Batteries, compare our Lithium Batteries, or contact Battery Warehouse for practical advice tailored to your setup.

Frequently Asked Questions About Battery Capacity

How many amp hours do I need?

The answer depends on three things:

• How much power your appliances use.
• How many hours you’ll be using them.
• The type of battery you choose.

A small camping setup with a fridge and lights may only need around 100–120Ah, while larger caravans or off-grid systems often require 200Ah or more.

Use the calculator earlier in this guide to estimate your daily power consumption before choosing a battery.

Is a higher amp hour battery better?

Not always.

A higher amp hour battery simply stores more energy, allowing it to power equipment for longer between charges.

However, larger batteries are also:

• More expensive
• Heavier
• Slower to recharge
• More difficult to install

The best battery is the one that comfortably meets your power requirements without paying for capacity you’ll never use.

Can I replace a 100Ah battery with a 120Ah battery?

In most cases, yes.

Provided the battery:

• Fits the available space
• Has compatible terminals
• Is suitable for your charging system

A 120Ah battery can often be a straightforward upgrade from a 100Ah battery, giving you longer runtime between charges.

Does a larger battery charge more slowly?

Generally, yes.

A larger battery stores more energy, so it usually takes longer to recharge using the same charger.

For example, a 200Ah battery will typically require significantly more charging time than a 100Ah battery.

If you’re relying on solar panels or a DC-DC charger, it’s important to ensure your charging system is appropriately sized.

Does a lithium battery last longer than an AGM battery?

In most applications, yes.

Lithium batteries typically offer:

• More usable capacity
• Faster charging
• Lower weight
• Longer cycle life
• Better performance during repeated deep discharges

While they cost more initially, many regular campers and caravan owners find lithium batteries provide better long-term value.

Can I use a starting battery as a deep cycle battery?

No.

Starting batteries are designed to deliver a very large burst of power for a few seconds to start an engine.

Repeatedly deep discharging a starting battery will dramatically shorten its lifespan.

If you’re powering camping equipment, lights, pumps or inverters, you’ll need a deep cycle battery designed for that purpose.

Is two smaller batteries better than one large battery?

Sometimes.

Many larger systems benefit from using two medium-sized batteries instead of one very large battery.

Advantages can include:

• Easier handling
• Better weight distribution
• Greater installation flexibility
• Easier future replacement

Every installation is different, so it’s worth discussing your setup with an experienced battery specialist.

Which Battery Is Right for You?

The table below provides a simple starting point.

Remember, these are general recommendations only. Your actual requirements depend on how much power you use each day.

Common Battery Buying Mistakes

Choosing the right battery isn’t just about finding the biggest number on the label.

Some of the most common mistakes include:

Buying based on price alone

The cheapest battery isn’t always the best value.

A quality battery often provides better reliability, longer service life and lower cost over time.

Choosing the biggest battery available

More capacity isn’t always better.

Extra weight, longer charging times and higher costs may not provide any real benefit if your power requirements are modest.

Ignoring battery chemistry

AGM and lithium batteries behave very differently.

Understanding usable capacity, charging requirements and expected cycle life can make a significant difference to long-term performance.

Comparing batteries using different test standards

When comparing deep cycle batteries, always check that the advertised amp hour ratings have been measured using the same C rating.

A battery rated at 100Ah (C20) isn’t directly comparable with one rated at 100Ah (C100) because they’re measured under different discharge conditions.

If two batteries are tested using the same standard, you’re making a much fairer comparison.

Before You Buy

Ask yourself these five questions:

1.What appliances will I run?

2.How many hours each day?

3.How many days between charging?

4.AGM or Lithium?

5.Do I expect my power requirements to grow in the future?

Answering these questions first usually makes choosing the right battery much easier.

Helpful Battery Resources

If you’d like to learn more before choosing your next battery, these guides are a great place to start:

• Choosing the Right Deep Cycle Battery
• Understanding Battery Power
• Car Battery Buying Guide
• Battery Terminals Explained