Buying a Portable Fridge (Pt 1) | Portable 12V Power Options (Pt 2)
You can power your portable fridge from the car’s 12V Cig socket – but only while the vehicle engine is running and the alternator is charging the vehicle’s starter battery. Once the engine is turned off, you will need an alternative 12V power supply to keep the drinks cold without leaving you stranded with a discharged starter battery
12V Portable Power Basics
Lithium batteries have transformed portable 12V power options. They are relatively lightweight and long lasting, compared to older lead-acid batteries..
The stored energy capacity of a Lithium battery is measured in Amp Hours (Ah). But you shouldn’t completely flatten a Lithium battery by using all the stored energy – consider 80% of the label capacity as the ‘usable’ capacity. So, a 100Ah Lithium battery has a ‘usable’ capacity of 80Ah.
Most portable 12V chest fridges consume about 1Ah of battery capacity every hour. If your portable battery has a rated capacity of 50Ah, you will get about 40 hours of fridge run time, if you take into account the 80% rule. Of course this will vary considerably if you store the fridge in the hot sun, or continually open the fridge lid and let the cold air out!
Listed below are some portable 12V options to power your fridge independently of the vehicle starter battery….
The Most Portable 12V Power Option
Lithium Power Packs are ideal for day trips and short weekend excursions. Equipped with a 12V Cig socket and USB ports, these Power Packs start at around $100 for a 12Ah pack, up to $300 for a 36Ah power pack.
Power Packs can be recharged from a USB charger, but may take several hours to recharge from 20% to 100%.
Power Packs: Adventure Kings | KickAss
The Built-in Battery Option
Only available in the Brass Monkey range, this is the really simple, no fuss, all-in-one option, for up to 10 hours of unsupported fridge run-time. Many Brass Monkey fridges include a click-in compartment to house an (optional) built-in battery. These fridges run directly from the vehicle’s 12V cig socket or a 230V outlet when available, then switch automatically to the internal battery when the external power supply is disconnected.
The Brass Monkey fridges with a battery compartment also include built-in regulators to recharge the battery from 12V, 230V or solar. If the fridge is plugged into external power (12V or 230V), the battery will be charging while the fridge is running.
The largest internal battery available is 15.6 Ah. Very handy for short trips, but easily recharged from a 12V cig socket (or solar panel) while travelling.
Built-in battery: Brass Monkey Fridges with Battery
High Capacity on a Budget
There is a hint of DIY in this option, but a Lithium battery fitted in a powered Battery Box is the cheapest way to get a 100Ah (or 120Ah) 12V portable power supply.
You can setup a 100Ah battery in a battery box for around $250 (Kings). This will give you a long fridge run time – up to several days – along with 12V outlets for other 12V appliances (like air pumps) and USB charging ports for phones and tablets.
You will also need a 230V AC-DC battery charger to restore the battery’s capacity when its’ energy storage is depleted. A charger with an Anderson plug is ideal for connecting easily to the Battery Box.
Battery Boxes: Kings 100Ah Combo | Dune Battery Box | Dune 120Ah Battery
230V Battery Chargers: Dune 12A | Kings 40A | KickAss 22A (with Anderson Plug)
The All-in-one Portable Power Option
All-in-one 12V Power Stations are now widely available, and are becoming more affordable – though they are still at the top end of the budget spectrum.
Power Stations have a built-in Lithium battery, with a variety of power outlets, including a 230V socket, as well as built-in charging regulators for 12V, 230V and solar inputs. All in one easy-to-carry box with a handle.
Power Stations increase in cost with greater battery capacity. Be wary of the marketing spiel – Power Stations are often advertised based on the Watts available from the 230V socket, or the battery capacity rated in Watt Hours (Wh) – because these numbers are bigger that the Amp Hour (Ah) battery capacity.
The smallest Power Stations have a 20Ah battery (240Wh), which will be fine for day trips or maybe an overnight excursion. A 40Ah battery (480Wh) will give you a longer run time, and may also double as a camping utility power supply. These smaller Power Stations kick off at around $400 for 20Ah capacity. Medium sized power stations (80Ah, 1000Wh) are around $1000, while larger 100Ah (1200Wh) Power Stations are up around $1500. Not cheap, but all fully self contained, and with a 230V socket for running small appliances. (Your fridge runs from the 12V sockets.)
Power Stations: EcoFlow 20Ah | iTechWorld 20Ah | Kickass 40Ah
Charge Me Up!
Batteries store electrical energy. Whichever portable power supply you choose, the battery will need to be recharged when it’s stored electrical energy is exhausted.
Use a suitable 230V AC-DC charger to recharge your battery/Power Station from mains power the night before you will be using the fridge. (If storing a Lithium battery for a couple of months or more leave it charged at about 60%, for long term battery health.)
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- Power packs can be recharged with a USB adaptor;
- Battery Box setups are best recharged with a 230V smart charger;
- Brass Monkey fridges with a built-in battery have a built-in 230V charger;
- Power Stations have a built-in 230V charger to recharge the internal battery.
For picnics and day trips, a battery that has been fully charged the night before should keep your fridge cold all the following day – with sensible fridge use.
If you are running your fridge off-grid for an extended period of time, you can also recharge a 12V battery with a solar panel. Again you will need a suitable solar regulator connected between the panel and the battery. Some power packs have the necessary regulating electronics built-in, but have a limited solar power input (around 70W)..
Most Portable Power Stations have built-in regulators for solar charging, mains charging, and 12V charging while you are driving.
230V Chargers & Solar Panels:
Adventure Kings | KickAss | iTechWorld | Anaconda
Heaps more info: Portable 12V Power Options with a Fridge