If you want to get off the grid, you need a way to make power. One of our favorite pieces of overlanding kit is the 4thD Solar XP170 portable solar panel. 

We’ve been testing this panel for over a year in every condition imaginable and it continues to be the perfect companion to the house battery installed in our Jeep Wrangler JL.


The 4thD Solar XP170 solar panel is easy to deploy and take down. We prefer a portable panel like this to a fixed panel on the vehicle because it can be moved throughout the day to follow and get the most out of the sun.

The 4thD Solar XP170 is a 170-watt, semi-flexible, tri-fold solar panel. It uses California-based Merlin’s patented MST (mono-crystalline silicon) technology, which addresses micro-cracking and fatigue-induced inter-cell interconnect failures, which results in a lightweight and durable panel that packs a punch. The XP170 is waterproof, weighs in at 12 pounds, and comes with a canvas carrying case.

Deploying the panel takes less than a minute and its adjustable legs allow for a zero to 36-degree angle, making it possible to get the correct sun angle just about anywhere in the United States. An Anderson SB50 connector is included and can interface with any battery controller using the SB50 standard.

Our Jeep utilizes an American Adventure Lab battery system managed by a REDARC BCDC 1225D battery charger. It has the ability to charge while the engine is running, and we use the attached 50Ah battery to power all of our camping accessories, including our Dometic CFX3 45 fridge.

When moving from camp to camp each day, the battery is fully charged by the engine’s alternator; however, if we decide to stay in the same place for a few days, the 4thD Solar XP170 has proven invaluable, especially if we are trying to avoid wasting fuel by running the engine.


Adjustable legs on the panel backside allow the user to adjust its angle from 0-36 degrees.


Using Merlin technology, the cells have a somewhat unique grid arrangement. A copper connector, rather than wires, connects the panels together in the folding seam and has been rated to 14,000 openings and closings before failure.

In hot weather, where our fridge is less efficient and might run throughout the night, or in cold weather, where we might be running a heating pad, it’s easy to chew through our battery reserve.

Fortunately, with good sunlight, the XP170 is capable of fully recharging our battery by lunchtime and keeps the battery topped off throughout the day. In high sun, with perfect conditions, we’ve seen the panel outperform its rating, and even on cloudy days in winter we still see 1-2 amps of power production.

The panel is fairly compact, measuring 28x68 inches in the open position and 12x23 inches folded, making it easy to stow in the back of the Jeep. For extended stays in our favorite secret spot, the 4thD Solar XP170 is a mandatory part of our multi-day camping trips, and we highly recommend it. 


Here’s an up-close look at the cells, each having thousands of redundant connectors so that in the event of any damage the cell can still make power.


We’ve found the XP170 solar panel to be the perfect companion to our house battery setup, allowing us to stay off the grid for many days and keeping us from idling our engine to charge with an alternator.

Cell Type: Mono
Number in Series: 36
Rated Power (Pmax): 170 watts
Voltage Pmax: 18.92 Vdc
Current Imp.: 8.46 amps
Voc: 23.01 Vdc
Isc: 8.72 amps
Active Area Efficiency: 18.19%


4thD Solar
XP170 Portable 170-Watt Solar Panel
URL: 4thdsolar.com


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This article originally appeared in OVR Issue 02. For more informative articles like this, consider subscribing to OVR Magazine in print or digital versions here.