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induction
cooktops
& lithium
battery sizing
What Size Lithium
Battery Do I Need to Run an Induction Cooktop or Air Fryer?
If you're planning on installing an induction cooktop or air fryer
in your camper trailer, caravan or motorhome, you've probably asked
yourself one question... What size 12-volt battery do I need?
The answer isn't as simple as buying the biggest battery you can
afford. One of the biggest mistakes people make is looking only at
the battery's amp-hour (Ah) rating. While battery capacity is
important, it's only half the story.
Battery Capacity vs Battery Output
To run appliances like an induction cooktop or air fryer, your
battery needs to do two things.
- Store enough energy.
- Deliver enough current.
Let's use a typical 2000-watt
appliance as an example.
Running through a 12-volt inverter, a 2000-watt appliance can draw
around 160 amps from your battery bank. That's a huge amount of
current.
Why Some
LiFePO4 Lithium
Batteries Won't Run High Powered Appliances
Many 100Ah and 120Ah
LiFePO4 Lithium batteries are fitted with
a Battery Management System (BMS) rated at 100 amps continuous
output. Although these batteries may have enough stored energy, they
simply can't supply the current required by a large induction
cooktop, air fryer or electric kettle.
If the appliance demands around 160-amps, the
LiFePO4 Lithium battery's BMS will usually
shut the battery down to protect itself. This is why it's important
to look beyond the battery's amp-hour rating.
Connecting Batteries in Parallel
One solution is to connect multiple batteries together.
For example, two 100Ah
LiFePO4 Lithium batteries with 100-amp BMS
units connected in parallel can supply up to 200-amps continuous
output. Now the battery bank has enough output to comfortably
operate a 2,000-watt inverter while still supplying power to your
fridge, lights and other accessories.
Not all Lithium batteries are the same.
Multiple batteries aren't always required.
Many premium
LiFePO4 Lithium
batteries are now fitted with much larger BMS units.
Some 200Ah and 300Ah batteries are capable of supplying 200 amps,
while others can deliver 240 amps continuous output from a single
battery. This means a quality
LiFePO4 Lithium battery with a
high-current BMS may comfortably run a 2,000-watt inverter without
needing multiple batteries connected in parallel. This is why
comparing
LiFePO4 Lithium batteries purely on
amp-hour capacity can be misleading. Two batteries may both be rated
at 200Ah, but if one has a 100-amp BMS and the other has a 240-amp
BMS, they'll perform very differently when running high-powered
appliances.
The Biggest Power Users in a Caravan
Some of the biggest power users we commonly see include:
- Induction cooktops
- Air fryers
- Electric kettles
- Coffee machines
- Hair dryers
- Microwaves
These appliances don't normally run for long periods, but they draw
a lot of power while they're operating.
Real-World Testing
At Totally 12 Volt, we like to back up the theory with real-world
testing. To see how much power these appliances actually use over a
typical camping weekend, we tested a camper fitted with a 300Ah
LiFePO4 Lithium battery bank and a quality
inverter. The battery bank received no charging from solar, the
vehicle or mains power during the test.
Over the weekend the following appliances were used:
Friday Night - 1800W induction cooktop for approximately 40
minutes.
Saturday Morning - 2000W electric kettle for morning coffees.
Saturday Lunch - Air fryer for approximately 25 minutes.
Saturday Dinner - Air fryer for another 25 minutes.
Sunday Morning - 2000W electric kettle for morning coffees.
At the end of the weekend, the Victron SmartShunt recorded a total
battery usage of approximately 309 amp-hours. The test highlighted
just how much energy high-powered cooking appliances can consume
over a weekend of free camping. While none of these appliances were
used for extended periods, together they placed a significant demand
on the battery system.
The Takeaway
Choosing the right battery system isn't just about buying the
biggest battery. You need a battery that can:
- Deliver enough current.
- Store enough energy.
- Work with the correct inverter.
- Be supported by enough charging capacity to replace the energy
you've used.
When all of these components are matched correctly, cooking with an
induction cooktop, air fryer or kettle while free camping becomes
simple and reliable.
Need Help Choosing the Right Battery
System?
Every camper is different.
Some people only make a morning coffee, while others cook every meal
using 240V appliances.
That's why we take the time to understand how you travel before
recommending a battery system.
If you're planning a new lithium battery system
for your camper trailer, caravan or motorhome, get in touch
with Totally 12 Volt.
We'll help design a system that's matched to your camping style, not
just a battery size.
article by Shane Adams
July 2026
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