It’s time to ditch the disposables.
Issue 144: May/June 2022
When it comes to batteries, dockside debates nearly always default to the rapidly evolving technologies that are changing how we power our big electrical needs onboard. The small batteries we use on our boats get less attention— but these technologies are changing for the better, too.
On Sooner, my Rafiki 37, I’m always looking for ways to be more efficient and environmentally thoughtful, and when it comes to the small batteries onboard like AAs and AAAs, I’ve switched to rechargeables. Like their larger cousins, rechargeables have gone through a quiet revolution. They now last as long as non-rechargeable alkaline batteries, they can be charged hundreds of times, and they quickly pay for themselves.
A good-quality charger is a key to success
for using rechargeable batteries onboard.
Consider, for instance, that an eight-pack of Duracell alkaline batteries that you’ll use once and toss costs about $8 on Amazon, while the same count of good-quality EBL AAA NiMH rechargeables, which the manufacturer’s specs say can be recharged up to 1,200 times, costs just $5 more.
That said, there are caveats, and the most important one—which goes for a lot of sailing things—is simple: Don’t cheap out. A cheap, no-name rechargeable battery will take you right back to the technology of the ’90s, quickly frustrating you with long charge times, low run times, and even leaking corrosive white goop.
On the other hand, a decent brand such as EBL or even Amazon Basics will last for years, save you from buying hundreds of disposable batteries, and cost only around $2 per battery. And high-capacity versions—2800 milliamps (ma) for AA and 1100 ma for AAA—often outperform disposable batteries in high-current applications.
Likewise, buying a cheap charger will doom your batteries—even decent rechargeables—to a quick, disappointing death. Without taking into account the state of charge, ultra-cheap chargers tend to just hammer on the power and will toast your batteries faster than you can say, “What’s that funny burning smell?”
A decent charger like the Panasonic BQ-CC55 costs about $25 and can charge AA or AAA batteries. For those without easy AC power, chargers like the Panasonic BQ-CC75ASBA use a USB cable. On Sooner, I use the EBL 6201. It’s inexpensive, tiny, charges AA and AAA, and runs off 12 volts via USB.
There are some applications when a rechargeable might not be the best choice. For instance, most manufacturers of carbon monoxide detectors recommend using disposable alkaline batteries.
In other cases, some items may not work as well with rechargeable batteries. Most modern rechargeable batteries are made of nickel metal hydride, and a AA will supply 1.2 volts. An alkaline disposable battery, made of zinc metal and manganese dioxide, supplies 1.5 volts.
However, the voltage in that disposable alkaline battery drops off fairly heavily, from 1.5 volts at full charge to 1.2 volts at 70%, all the way down to 1 volt at 20% charge (all voltages are under a light load). Rechargeable batteries, in comparison, hold their voltage all the way down to around 20% or so, where it then rapidly drops off.
Most devices are designed to work at voltages between 1.5 and 1 volts (or multiples of that for more powerful devices using batteries in series), so rechargeable batteries’ starting voltage of 1.2 volts shouldn’t really come into play. However, for some older or simpler devices, you may find that your light isn’t as bright or there is some unusual behavior. I have never come across a device that didn’t work just fine with rechargeable batteries, but it is something to be aware of before you start tossing your old single-use batteries to make way for rechargeables.
For those worried about possible incompatibility, 1.5-volt rechargeables, which use Li-ion instead of NiMH, are an option. Charged directly with a USB cable rather than a charger, they cost three to four times more than NiMH batteries. Unless you have a very voltage-sensitive device, in my opinion they are not worth it.
To keep track of my batteries aboard Sooner, I keep a box of fully charged batteries. When a device runs out, I switch the old ones out, putting the discharged batteries into my “recharge” box. I recharge these en masse later and return them to my “charged” box.
Switching to rechargeable batteries saves money, eliminates the hassle of finding somewhere to dispose of used non-rechargeable batteries (which in many places are considered hazardous waste and can’t be thrown in general garbage), and limits the concentrations of zinc and manganese dioxide (a cumulative neurotoxin) in the environment and your body. For me, it’s a no-brainer
Matt Parsons has been living aboard and cruising sailboats for 10 years. He currently lives on Sooner, a Rafiki 37, in Victoria, British Columbia, and keeps a blog at saildivefish.ca.
Thank you to Sailrite Enterprises, Inc., for providing free access to back issues of Good Old Boat through intellectual property rights. Sailrite.com
