Skip to main content

USB Electronics Charging Offshore

It was easy to gather a slew of devices on board Gizmo that hunger for a USB power supply at least occasionally. Heck, when the Verizon Android Galaxy phone is providing an LTE Wi-Fi hotspot and also streaming Bluetooth audio to the Fusion IP700 stereo as it is now—
  • Author:
  • Updated:

It was easy to gather a slew of devices on board Gizmo that hunger for a USB power supply at least occasionally. Heck, when the Verizon Android Galaxy phone is providing an LTE Wi-Fi hotspot and also streaming Bluetooth audio to the Fusion IP700 stereo as it is now—I’m online while listening to a Maine radio station from the Chesapeake—it needs to be charged almost constantly.

The hard-working phone is another reason why I keep my two USB charged/charging batteries topped up for shore trips (and, yes, they do make great press event swag: thank you Simrad and FLIR!) as is my Phonak hearing aid accessory, which needs nightly charging. Then there’s the DeLorme InReach Explorer, which can go for days doing satellite tracking and a sending a few messages on a single charge, but which I prefer to keep plugged in so my Share Map stays complete.

In short, I need multiple 12-volt USB power sources to keep this crew happy and thus, this entry will cover several types I’ve tested. There are a lot of cables involved, but it’s nice that all the gadgets pictured use a standard USB mini or micro size power and data plug, with one very significant exception...

Of course, it’s the Apple iPad mini, which uses a proprietary Lightning connector instead of a standard USB plug. The tablet does have excellent battery life, and I understand that it needs more than a standard USB 5-volt 1 amp charger (or a 0.5 amp laptop USB port) to renew the battery efficiently. However, iPad charging issues go well beyond that.

For example, my experience is that even if you use a charger rated at the 2.1 amps purportedly needed by most iPads—newer models have gone to 2.4 amps—you can’t be sure that you’ll see the charging screen when you plug the Lightning cable in. There are endless online discussions about this. My hunch is that Apple is using a unique way of detecting a higher amperage charger that you’ll only find for sure in Apple Certified chargers, none of which is ideal for a boat. (Again, in my opinion.)

Before describing my search for a good marine iPad charger, let me also grumble a warning about the Lightning cable itself. The official Apple one that I had on board failed during my trip from Maine to Baltimore, which caused some anxiety as I didn’t have a spare, and I use the iPad mini a lot. Fortunately, I was able to get this connector to pass a charge again by gently sanding the contacts with fine emory paper lubricated with a little oil. Still, I’ve had Apple-made cables fail before, and the cheap knock-off cables I’ve tried have done even worse. The back-up Lightning cable I should have brought from home and highly recommend is Amazon’s own Apple Certified design. It seems sturdier than Apple’s and reasonably priced, especially given that Apple apparently gets a few dollars fee for every one sold.

By far the most common way to charge USB devices on a boat is with adapters like the ones pictured above at left. They fit what are now called “12v accessory outlets” though oldsters like myself know the “outlet” was designed for cigarette lighters. Unfortunately, this outlet offers, as Wikipedia notes, “poor contact stability,” even though my boat came with four such power receptacles installed. Of course, I tried them, and while adapters like the one with the 2.1 amp output sometimes charged my iPad, sometimes they didn’t. One day I realized the adapter had gotten quite hot, apparently because it was trying to draw those 2 amps through a poor contact. It was not the first time I’ve had such trouble, which is why I wonder if such “outlets” should be used untended.

A better alternative is a 12-volt USB power source designed to install behind a dash, which works neatly with accessories like the Tallon Ultimate iPad Mount or just a regular USB cable snaked to your favorite charging station. Both the CPT (no longer available) and the RioRand (available at Amazon) charge every USB device on Gizmo just fine...except the iPad. Even though both chargers claim a 3-amp output, sometimes the iPad says it’s charging, sometimes not. I realize that iPads often charge slowly even when they aren’t acknowledging it. But I was frustrated nonetheless and was often using the Apple AC charger with Gizmo’s inverter just to be sure.

Recently, I picked up a couple of USB chargers that are designed to replace an existing cigarette lighter receptacle—the Blue Sea Dual USB Charger Socket and a very similar XYZ Boat Supplies model (shown above right)—and despite my low expectations in terms of Apple compatibility, they have both worked very well. Specifically, my iPad mini has always shown charge status when plugged into the Blue Sea outlet, and only failed once when plugged into the XYZ’s high power outlet. I don’t know how either charger will work with the new iPads that like 2.4-amp charging. (But if anyone out there does, please let me know.)

Finally, don’t these annoying incompatible, worn cables make one yearn for a universal inductive charging standard? I don’t know if that will ever happen, especially for Apple devices, but at IBEX I saw how inductive charging is coming neatly to boats and will write about it soon.

For more of Ben Ellison’s insights into marine electronics, go to



Video: Celestial Navigation Pt3

. In episode three of the Practical Celestial Navigation course, Andy Howe examines the theory behind celestial navigation, the celestial triangle and the celestial sphere, and why it is important to have a basic understanding of each. Topics introduced include zenith position, more


Sailing in the Time of Covid

In mid-August 2019, my wife, Terrie, and I laid up our Malö 46, Nada, in Falmouth, England, and flew home to Maine. We booked flights back to the UK for May 2020, anticipating a summer of cruising the Atlantic coasts of France and Spain. Then Covid struck. Remember that first more

Ulysse Nardin promo photo

The Ocean Race Names Official Timekeeper

With just under one year before the start of The 2022-23 Ocean Race, Swiss watch manufacturer Ulysse Nardin has been named the official timekeeper of the race. The Ocean Race, formerly known as the Volvo Ocean Race and before that the Whitbread Round the World Race, announced more

Arthur Daniel_RORC Maserati - RORC Transatlantic 2022 - Jan 15th -Social Media-4

Fast Finishes for the RORC Leaders

Over the weekend, the first finishers of the 2022 RORC Transat made landfall in Grenada, led by Giovanni Soldini’s Multi70 Maserati, which was awarded line honors with a corrected time of six days, 18 hours and 51 minutes. Maserati finished ahead of Peter Cunningham’s MOD70 more


Notice to Mariners: A Blog from the SAIL Editors

As a teenager, I stumbled across a copy of Derek Lundy’s Godforsaken Sea in the back room of a used bookshop. I had never heard of the Vendée Globe and frankly found all the boat-speak in the first 50 pages a little difficult to get through. But Lundy’s storytelling and the draw more


VIDEO: Celestial Navigation Episode 2

Celestial navigation is an invaluable tool for all kinds of sailors. In episode two of the celestial navigation series, learn the basic elements of navigation and the sight reduction process using declination and GHA to determine the Geographic Position and navigate using a more


Cruising: Year of the Sea Shanty

Along with other timeless pursuits, like baking sourdough and gardening, singing sea shanties surged back into popularity during the recent lockdown, thanks, in part, to the app TikTok and its “duet” feature, which allows singers from around the world create music together. By more


Book Review: Sailor Song

Sailor Song is the ultimate guide to the music of working sailors during the 18th and 19th centuries. The book includes lyrics and sheet music for 50 of the most beloved sea songs with fascinating historical background on the adjoining page. Chapter introductions provide more