Question: Is there any benefit in having a 40 amp AC charger if my shore power is 30 amps? Should I change to a 30 amp charger?
Answer: Actually we need to differentiate between AC and DC voltage and amps.
Your charger (aka converter from AC to DC) is powered via 120-volts AC and runs at less than five amps AC. The output of the charger is 40 amps at 12-volts DC. Therefore you can keep your 30 amps 120-volt AC receptacle and run your five-amps AC charger no problem.
Q: I am wondering if the Bad Elf GPS Pro would be useful for coastal navigation to pair with my iPad 1? My iPad does not have a GPS chip in it.
A: According to the Bad Elf website the GPS Pro works with all iPads. The Bad Elf GPS Pro has a built-in GPS and does require data coverage like the iPad does for navigation. Small note, probably best to make sure your iPad has the latest IOS software.
Q: I have 3 separate runs of 10 gauge (three wire) attached to my 30-amp shore power plug receptacle on the boat. I want to install a smart plug but there is not enough room for all those wires in the new smart plug. What would be the correct way to join these? Should I use some kind of junction box and have a single set of wires connected to the SmartPlug?
A: Your idea of junction box is correct; make sure it is sealed and only accessible with tools to prevent it from opening easily. Terminate the wires onto a terminal strip and then bring a pigtail to the Smartplug.
Q: What is the difference between battery monitors and amp meters? How many do I need for my boat?
A: Battery monitors and amp meters are quite different. Amps are a value like speed (i.e. km/h) but don’t provide you with the distance travelled. As with a car, your speed varies as you drive through a city. Amps only tell you the speed you are going at that moment. The battery monitor tells you the amount of battery capacity you have left. There is no substitute for a battery monitor.
Q: Are there any concerns with the floating neutral of the AC outlets when using portable, air-cooled generators on a boat for charging batteries?
A: There is no doubt it is a dangerous situation to forgo a ground return path. And, unless you tinker with the wiring inside the generator, there is no fix. As a rule of thumb, you should avoid using a portable generator because the ground and neutral are unconnected.
About the author: Jeff Cote is a systems design engineer and owner of Pacific Yacht Systems, a full service shop delivering marine electrical and navigation solutions for recreational boats. Visit their website and blog for info and articles on marine electrical systems, projects and more: www.pysystems.ca.