When I first started learning about boats’ systems, I was horrified at the complexity of keeping battery banks alive. It seemed like there were so many ways to kill a battery by neglect or abuse or just looking at it funny, that we ought to just throw up our hands and go back to oil lamps and hand crank starters. To compensate we’ve got big alternators, fancy regulators and multistage chargers that cost considerably more than the batteries themselves. Still, good old lead acid batteries have an Achilles heal that tends to kill them sooner or later, and that’s sulphation. Basically, when a battery is discharging, lead from the plates is converted into lead sulphate, and while charging, the sulphate is converted back into lead. The problem is that lead sulphate can form into crystals while the battery is discharged, and the crystals keep it from changing back into lead, and this results in a permanent loss of capacity. The traditional remedy for reduced capacity has been to do an equalization charge—a higher than normal voltage charge that can dissolve the crystals, but a procedure that requires close attention and some caution. Unfortunately, an equalization charge can cause permanent damage to sealed batteries such as gel cells and AGMs. An interesting option is a desulphator, an electronic black box that is attached to the battery terminals, and gives them brief, high frequency zaps, causing the lead sulphate crystals to dissolve. Users report being able to bring some old, dead batteries back to life, and considerably extending the lives of their battery banks.
There are plans on the web for those handy with a soldering iron, and a number of vendors are making electronic versions, some of which show up at the boat shows. Even some of the Vector automotive battery chargers have a desulphating setting to recondition cranky old batteries. Given the cost of replacing a substantial battery bank, another $100 or so for a desulphator could be pretty good insurance.
Links: desulphator forum
Many of you may already be familiar with Usenet forums like rec.boats.electronics and rec.boats.cruising, but I’d hazard a guess that while Usenet forums are ancient by internet standards, that many folks may not know what a great resource they can be. Luckily, Google acquired DejaNews a couple years ago, and made searching and posting to these discussion groups painless (configuring a news reader client used to be about as complicated as configuring an email account). And these groups are often the best places to ask and answer questions, and they tend to have greater reach and readership than some of the websites that host discussion boards. Recently I directed a reader with a question regarding Navman vs. Raymarine instruments to rec.boats.electronics, and he promptly got some good responses. And while I’d love for more of the readers of this website to post more questions and comments on Navagear’s articles, I really have to recommend Google Groups for finding relevant experience and discussions.
An application like this has been a surprisingly long time coming, but Marcus Tettmar’s PDAOnboard has released Pocket Repeater—software running on a Palm or Pocket PC PDA, that displays NMEA instrument data over a Bluetooth wireless connection. And if you are wondering how to interface your instruments with Bluetooth, 
Over the years there have been a number of efforts to build a better mousetrap in the “float switch” department. Obviously switches that rely on an actual physical float are prone to some problems over time, and those relying on a drop of mercury in the switch are environmentally sketchy as well. See Water Inc. has come up with a new solid state switch that is particularly notable in differentiating between water and fuel or oil in the bilge. With possibly large fines for such spills these days, it makes sense to take some precautions like replacing old fuel lines and making sure your fueling routine is basically spill-proof. However, if an old line ruptures, or you have a messy oil change, your dutiful bilge pump may enthusiastically pump the offending fluids overboard. This switch detects the difference between water and hydrocarbons and stops pumping when it detects the troublemakers. It also incorporates some microprocessor smarts so that when emptying water from the bilge, it’ll pump for a few seconds after it no longer sees water, thereby clearing the line so that you don’t get so much of a residual puddle. It’s a new product, so I haven’t seen any reviews on it yet, but it looks promising.
Ben Ellison over at 
If you have a Pocket PC or Windows Smartphone, Pocket Stars is a real treasure of an application. It not only takes the place of those phone book sized nautical almanacs used for celestial navigation, it’s a great reference for the night sky that you might actually have in your pocket when you can’t remember which star is Aldebaran and which is Arcturus. It’s a remarkably feature rich application, including moon phases, rise and set times, various handy navigation calculators, animated orbital paths and much more. Pocket Stars is the fine work of Jay Alan Borseth, a sailor and software developer. With a free 15 trial period to evaluate the software, a money back guarantee, and a very reasonable price of $20, it’s an excellent value. See his website, 
With integrated navigation systems such as 
Forespar’s Marelon thru-hulls and seacocks have been around for enough years now, that their plastic construction has proven to be reliable if properly maintained, i.e. lubricated regularly. There is no shortage of folks ready to tell you about the handle of a plastic seacock that has broken off in their hands and say “never again.” On the other hand, there’s always someone rushing to the chandlery to pick up some Marelon fittings after having a bronze thru-hull fail at the dock due to stray current corrosion. This is one of those areas where some honest self- and boat-assessment ought to be your guide. I.e., are you the type of person that will consistently lubricate and work the handle on your thru-hulls at least once a season, year after year? And are your thru-hulls in locations that could be broken by a heavy object, or even a foot, landing on them? If Marelon will work for you, check out these smart engine raw water valves. The neat thing is that there is a garden hose fitting for flushing saltwater out of the engine at the end of the season. Just attach the hose, flip the handle, and voilá!
