Portable power station components explained

In simple terms, the power stations were made up of a lithium battery, 240V charger, 240V inverter, 12V outlet (cig-plug), USB ports and XT60 DC input ports.

Lithium battery

At the heart of these power stations is typically a 24V to 51V battery, not 12V like the one in your in-vehicle system. Most use LiFePO4 chemistry and are typically good for 2000–4000 cycles, with a lifespan of around 10 years. A small number do use lithium-ion cells that are only good for around 500 cycles. LiFePO4 chemistry is also safer.

A higher-voltage battery reduces the required battery current, increasing efficiency at high power levels. Unlike a traditional auxiliary system, the user does not get direct access to the battery terminals. All inputs and outputs are via step-up or step-down converters.

240V charger

Unlike traditional 4×4 systems, all portable power stations have a high-power 240V charger, often rated at 1.2kW to 2.4kW, typically capable of charging the battery in two hours or less. This allows fast pre-trip charging at home or at a powered site when travelling. However, for extended remote travel without 240V access, this feature is of limited use.

240V inverter

These are typically rated at 1.2kW to 2.4kW on the higher-tier units, enough to power most 240V appliances and even large power tools. The practical limitation has more to do with battery stamina than power. In practice, what you can realistically run is determined by your ability to recharge the unit when out bush.

Discharging the battery is easy, and fast charging from 240V is simple too, but many of the stations we tested charged slowly from solar panels and extremely slowly from the vehicle electrical system. But we’ll get into that more in a sec.

Be aware that inverters draw significant current at idle. It is very inefficient to use the 240V output to power light loads of less than, say, 50W. Use the USB or 12V outputs instead. Even with no load connected, just having the 240V output turned on will typically flatten the battery at around 1% per hour.

Also, when you get home, make very sure every output is off or the battery may be completely discharged and even damaged. Most units can be set to turn off outputs automatically when not in use, but this feature must be used with care or it may turn off intermittent loads like your fridge, or very light loads like a phone being charged.

12V outlet (cig-plug)

Usually, these are limited to 10A. In part, this is because that is the limit of a cig-plug and socket, although a higher-current socket could have been provided in principle. Why wasn’t it? Because the internal battery is typically 24V to 51V, not 12V, so the 12V output is actually obtained from a step-down converter, and it would be expensive to include a powerful converter capable of more than 10A.

The only exceptions among the units we tested are the iTechworld PS2000 and Bluetti AC240, with dedicated high-current outputs of 25A and 30A respectively.

The other reason the 12V output is limited to 10A is efficiency. The 12V output will typically be used for low-power devices like a fridge or Starlink Mini, while higher-current appliances would be powered via the 240V inverter.

USB outputs

Almost all of the units provide an extensive selection of USB outputs, including high-power USB-C PD up to 140W. It is much more efficient to charge a device using USB power than to use a 240V brick adaptor. As mentioned, the idle power consumption of the inverters is quite high.

If a Starlink Mini is to be powered, do so from the 12V outlet rather than the 240V AC output. If efficiency and battery stamina are important to you, don’t use the 240V inverter for light loads unless you need to, and never leave it on unless it is actually being used.

XT60 multi-purpose DC input port

Most power stations we tested use a three-prong XT60 connector for all DC inputs. This style of connector was developed for RC models but has been embraced by the power station industry for its high-current capability. A couple of stations do use a different connector, but the XT60 is the most common, so we’ll just use the term “XT60” for simplicity.

The XT60 is used for DC charging from solar panels or via the cig-plug in the vehicle. The speed at which the power station can be charged from solar or your vehicle’s alternator – rather than from 240V – is really important.

While it would be great to know the charging current and available power from the cig-plug or solar input, this information is generally unavailable and there’s no industry standard for XT60 connections. All you can do is plug her in and wait, with no data on how long it’ll take to charge your power station from your vehicle. Obviously, this sucks.

That’s why we lab-tested each XT60 input port to understand how it works and what charge current you will actually get in the real world. 4X4 Australia is the only one to have done this.

Now, the intelligent XT60 “looks” at the applied voltage at the port and sets the maximum charge current it will accept according to that voltage. In the real world, there are three situations where this information is beneficial:

1. When charging from the vehicle alternator while driving

The charging voltage with the engine running will be around 13.2V. In general, the XT60 will accept no more than 8–9A at 13.2V to protect your vehicle’s cig socket. Even with heavy cabling to the XT60, the current will still be strangled to about 8A. For the larger power stations, that means a recharge time of 10 to 20 hours while driving, which is near useless.

The industry solution is to buy a ‘fast alternator charge module’ at extra cost. These basically step up the alternator voltage to 36V or more. The XT60 will accept much more DC charging current and power at this voltage.

2. When connecting a single 12V solar panel

A panel, or multiple panels wired in parallel, operates at about 18V. For most units tested, the maximum current the XT60 will accept at 18V is also 8–9A, due to the smart (dumb) XT60 thinking it still needs to protect the cig socket. This means the largest single panel or blanket the XT60 port can fully utilise is around 18V x 9A = 162W.

Plugging in a larger panel than that does not help – the port will refuse to draw more than 9A. The iTechworld PS2000, Jackery 1000 and VoltX S2200 are exceptions, allowing around 20A or 360W from a single panel, which is pretty good, while the EcoFlow Delta 2 can be programmed to accept 15A or 270W. But with the other stations, be very careful, because if you own or buy a single solar panel rated at more than about 160W, any capacity above that will be wasted. The solution is to use two panels in series.

3. When connecting two 12V solar panels in series

Two 12V solar camping panels or blankets wired in series operate at about 36V. At this input voltage, much higher charging power – from 350W up to 750W – can be utilised. The reason is that the smart XT60 knows the vehicle’s cig socket cannot be as high as 36V and therefore raises the current limit. Combined with the increased current capability and the doubling of voltage from two panels in series, seriously beneficial solar inputs become possible.

As a quick case study, consider the iTechworld PS2000. When charging from the alternator at 13.2V, the maximum charging current into the XT60 is 8.2A, which equates to a piddling 108W. However, a 500W fast alternator charger is available, which is almost five times faster.

When a single 18V solar panel is connected, the maximum current accepted by the port is 20A, equating to 360W, which is very acceptable and roughly double that of competing power stations. However, by wiring two panels in series – or four panels in series-parallel – to produce 36V, the port will accept up to 13.9A, which equates to 500W. Chicken dinner.

Just quietly, also of interest is the maximum power the XT60 port will accept, regardless of voltage. For the PS2000, for example, the maximum XT60 input voltage is 50V, so two solar panels in series is fine, but three is not, and there is an absolute 500W limit regardless of voltage.

This wealth of information is simply not available in the power station manuals or anywhere else. On our part, it took a lot of lab work to measure this information, but we reckon it was worth it.

Testing notes

  • All testing was conducted at 25°C ambient temperature.
  • Boiling one litre of water in an electric kettle, starting at 15°C, requires 0.116kWh based on direct measurement.
  • A typical 13-inch laptop with a 55Wh battery requires about 69Wh from the USB port for a full recharge, assuming 80 per cent USB charging efficiency.
  • A typical mobile phone with a 5Ah battery requires about 22Wh from the USB port for a full recharge. This is based on 5Ah × 3.75V = 18.75Wh, divided by 85 per cent USB charging efficiency.
  • For USB charging, the USB port inverter is assumed to have the same efficiency as the 240V inverter at the two-hour rate, so the measured 240V Wh figure can be used.
  • For the 35L fridge, power consumption is calculated as 0.8A × 13V = 10.4W.
  • For the 12V output, the inverter is assumed to have the same efficiency as the 240V inverter at the two-hour rate, so the measured 240V Wh figure can be used.