120Ah Lithium · Runtime

How long will a 120Ah lithium leisure battery actually last?

The 120Ah is our mid-size all-rounder and the natural step up from a 100Ah lead-acid. It drops into most DIN tray setups and suits weekend and touring vans well. Here is exactly what a TITAN 120Ah delivers, with real runtimes for the kit most people carry.

View the TITAN 12V 120Ah→ Size it for my setup→
120Ah
Rated capacity
1536Wh
Usable energy
1.54kWh
Per full charge
240Ah
Lead-acid for the same

What a 120Ah TITAN runs, and for how long

Figures assume a usable 1536Wh from a full charge. Items marked AC run through an inverter, so we have allowed for around 10% conversion loss. Real life varies with temperature, cable runs and how hard the kit works.

ApplianceTypical drawRuntime
12V compressor fridge 40 W ~38 hours
LED lighting 12 W ~5.3 days
Diesel night heater 18 W ~3.6 days
Water pump 60 W ~26 hours
Phone and tablet charging 12 W ~5.3 days
Laptop 60 W ~26 hours
TV or projector 45 W ~34 hours
Wi-Fi or 4G router 10 W ~6.4 days
Electric blanket 45 W ~34 hours
CPAP machine 40 W ~38 hours
MicrowaveAC 800 W ~104 min
Coffee machineAC 1000 W ~83 min
1800W induction hobAC 1800 W ~46 min
2000W kettleAC 2000 W ~41 min

Runtimes are a single appliance running on its own from 100% to empty. In the real world you run several at once, so use the battery size calculator to total your daily draw and size the bank properly.

How many days off-grid?

A 120Ah TITAN holds a usable 120Ah. Match that to a typical day's use and you get a realistic time between charges, before any solar or alternator top-up.

Light weekender
3.0 days
~40Ah per day. Fridge, lights, phone charging and the odd pump cycle.
Typical touring
1.6 days
~75Ah per day. Fridge, lights, diesel heater, water, TV and device charging.
Heavy or full-time
1.0 days
~120Ah per day. All of the above plus regular inverter use for cooking and appliances.

The same days, with a 100W solar panel

A single 100W panel puts back around 25Ah a day on average between April and October, the months most people are actually out. That daily top-up slows the battery down like this, before any driving or hook-up.

Light weekender
8.0 days
~40Ah used, ~25Ah back from solar, so about 15Ah net a day.
Typical touring
2.4 days
~75Ah used, ~25Ah back from solar, so about 50Ah net a day.
Heavy or full-time
1.3 days
~120Ah used, ~25Ah back from solar, so about 95Ah net a day.

Those solar figures use one average 100W panel. For your exact panels, roof and time of year, run the numbers in the solar calculator.

Lithium vs lead-acid at 120Ah

This is where the rated number misleads people. A lead-acid leisure battery should only be taken to around half its capacity before it starts to wear out fast, so a 120Ah lead-acid gives you roughly 60Ah of safe, usable energy. A TITAN lithium of the same 120Ah rating gives you the full 120Ah, because LiFePO4 happily delivers its entire rated capacity.

Put simply, you would need around a 240Ah lead-acid bank to match the usable energy of this one TITAN battery, at roughly double the weight and a fraction of the cycle life. That is the real reason lithium wins on anything where weight, space or how often you charge actually matters.

The 120Ah is the easy upgrade from a tired 100-110Ah lead-acid. It fits the common DIN Type 019 footprint, so for many vans it is a straight swap, and it gives you more than double the usable energy at roughly half the weight.

See full specs and price→

Common questions

How long will a 120Ah lithium battery last?
A 120Ah TITAN gives a usable 1536Wh, roughly 120Ah, from a full charge. That runs a 40W compressor fridge for about 38 hours, or covers a light weekender for around 3.0 days between charges. Heavy users with inverter cooking get closer to a day.
How many amp hours can I actually use?
All of it. A TITAN gives you the full 120Ah to use, 100% usable capacity, which is about 1536Wh. A lead-acid of the same rating only safely gives you around half before it starts to wear out.
Will a 120Ah battery run a kettle or induction hob?
Through an inverter, yes, but only in short bursts. A 2000W kettle pulls around 165A from a 12V battery, so this pack would boil for roughly 41 minutes total on a full charge. For regular cooking you want a bigger bank, a high-output inverter and ideally more than one battery.
How long does it take to recharge?
It depends on the charger. From a 30A mains charger or DC-DC unit, a flat 120Ah pack refills in around 4.0 hours. A 50A charger does it in about 2.4 hours. TITAN packs take a high charge current happily, so the limit is usually your charger, not the battery. Check the charger compatibility list.
Can I charge it from the alternator while I drive?
Yes. The way we recommend is a DC-DC charger, also called a battery-to-battery charger, ideally a Victron Orion, which gives the lithium a clean, controlled charge and protects the starter battery. A standard split-charge relay does work, but it is not the most reliable way to charge lithium and some relays cause a backfeed that quietly skims around the top 15% off your usable capacity. Feeding straight off the alternator with no relay and no DC-DC is not something we recommend.
Is this enough for my van or boat?
For most weekend and touring setups, yes. Full-timers and anyone running inverter appliances regularly should size up or add a second battery. The quickest way to be sure is the battery size calculator, which totals your daily draw and recommends a capacity.

Compare the range

Every TITAN leisure battery is LiFePO4 with a custom TITAN BMS, IP67 casing and a lifetime, fully transferrable warranty. Pick the capacity that matches your use.