A powerbank is simply a battery in a box, with an inverter and some 240V and 12V sockets. This duplicates the systems your motorhome has on board. 

Now, Ecoflow’s Delta Max battery-to-battery (B2B) charger aims to challenge this view. The Alternator Charger is a compact, stylish B2B charger that works solely with Ecoflow products. 

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The Alternator Charger is available for £329 but here, I was testing it with the Delta Max 2000 portable power station. The best portable power station for a campervan can make a huge difference to the on tour experience, providing standalone power, so I was interested to see how this got on.

The Alternator Charger comes with its cabling pre-terminated and all you need to install it. To set up, connect the two terminals to the battery (the positive is already fused), run it through the vehicle, then plug it into the unit. A second wiring loom links the powerbank to the Alternator Charger.

The Ecoflow Alternator Charger kit
The Ecoflow Alternator Charger comes with everything you’ll need to install it

Now fire up the app and you’re good to go. The app has various options – you can have a traditional B2B charger where it recharges the Ecoflow battery at up to 800W (the powerbank runs at 40-60V, so this means up to 20A), which enables a completely flat Ecoflow powerbank to be charged in a couple of hours. 

The Ecoflow Delta Max 2000
The Ecoflow gadget has plenty of USB and power sockets

In practice, it’s not quite that fast – smart alternators in modern vehicles vary the charge via the ECU – but it’s quicker than a split-charge relay and will recharge your Ecoflow while you drive.

The secondary functions are equally useful. As my camper hadn’t been used for a while, the battery charge wasn’t that high, so when I set the Alternator Charger to ‘reverse charge’ in the app, I was very pleased to see the vehicle battery voltage zooming up. No more messing about with jump leads for a flat battery. 

Plugging in the loom
Plugging in loom is idiot-proof, thanks to labelled connectors

As for the Delta Max 2000 powerbank, it has a 2016Wh battery, which equates to a 40Ah lithium battery (about the equivalent of an 80Ah lead acid). However, it runs at 50.4V, more efficient than running at 12V. 

It also features a 2400W pure sine wave inverter (supporting up to 3000W with an X-Boost function), with four 240V three-pin UK sockets, four USB-A outlets, two USB-C outlets and a 12V cigar-style socket.

For any combination of devices plugged in, the display tells you how long the battery will last. At £899 it’s not cheap, but a good 2400W sine wave inverter on its own would cost £500. 

The Delta Max 2000
Delta Max, weighing 22kg, offers proper power for its size. Strap it in on the road to keep it secure

At 22kg, the Delta Max 2000 is not that portable, but it’s ideal for powering devices under an awning or cooking al fresco. I tested it with an 1800W air fryer before touring (see: the best air fryer for a motorhome if you’re after one), then a 1500W fan heater in the motorhome. It ran both without issue. 

The major benefit of the powerbank is its flexibility and mobility – it can power almost any device, anywhere. It removes the worry of flattening your leisure battery. I see it being very useful for charging ebikes and the like, for this reason.

Interested in a less powerful portable power bank? The Bluetti EB3A impressed Deputy editor Paul Critcher when he tried it out, providing wireless phone charging and the ability to charge a laptop and four iPhones. With a lower weight of only 4.6kg, it has a battery capacity of 268.8Wh.

Ecoflow Alternator Charger

  • Charge: Up to 800W
  • Connectivity: App & Bluetooth
  • Price: £329
  • Weight: 2.3kg

Delta Max 2000 Powerbank

  • Power: 2016Wh 50.4V battery (40Ah)
  • Outputs: Four USB-A outlets and two USB-C
  • Dimensions: 49.7 x 24.2 x 30.5cm (L x W x H)
  • Weight: 22kg
  • Price: £899

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