As part of my power upgrade project, I needed to relocate and move around some things, and stumbled across the Egis XD NMEA 2000 Relays. After running them for 6 months on three battery banks I'm very happy with the results.
Egis as a Manufacturer
Egis Mobile Electric is based in Bellingham, Washington. The company was created in 2018 through the divestiture of Copeland Engineering, which had spent over 20 years building electro-mechanical and solid state time delay switching devices, mostly for emergency vehicle and municipal fleet markets.
The leadership team is led by Eric Graham, who spent 15 years in the marine, commercial vehicle, and emergency vehicle markets, developed products and led engineering at Blue Sea Systems, then ran Terra Power Systems, and later held leadership roles at Littelfuse including Global Managing Director for the Commercial Vehicle Products division. That's a background you'll recognize if you've spent any time around Blue Sea gear, and it shows in how Egis approaches build quality and documentation.
The company makes relays, ACRs, fuse blocks, busbars, and circuit protection products, and everything is designed and built for wide temperature range and vibration, the kind of conditions you can expect aboard a boat.
I have used a number of Egis products including their Class-T fuse holders, relays, battery switches, relay bars, and more, and have found their products to be extremely well made with beefy components, thoughtful design, and they just work really well.
Egis XD Relay Overview
The Egis XD series includes a number of different high amperage relays and ACRs including the single NMEA 2000 type I am reviewing here. They also have dual relays, a relay and a ACR, triple versions with two relays and an ACR, and standard relays without NMEA 2000 connectivity. They have a ton of combinations that can give you a lot of flexibility and options.
I have several types aboard Aruna including the XD NMEA 2000 Single Relay and the XD Single. The XD Single is a 500A heavy duty battery switch which I use as a shutoff for my inverters.
The XD NMEA 2000 Single Relay is the subject of this particular review, with general specs below:
- 500A continuous / 1600A cranking
- Heavy duty construction - Sealed to IP67/IP6K9K, high temperature electronics and materials. Stainless steel cable lug studs. Large mounting holes accept 1/4-20 / M6 attachment hardware.
- NMEA 2000 controllable, while also responding to optional discrete remote controls.
- Reports switch status, status of manual override knobs, and battery voltage on input terminals to the NMEA 2000 network.
- Manual override knobs provide ability to lock switches ON or OFF for servicing or if control power is lost.
- Simple programming via dip switches for NMEA 2000 instance selection and battery voltage reporting, and Close/Open set-points on voltage sensing relays in Dual/Triple XDs
You can find the full specifications either at the Egis store or in their PDF on the XD series.
I really like the fact that you can program these with dip switches, which means quick and easy installation without extra software or connections, that the ON/OFF override knob is very obviously labeled and easy to ensure it is in the right position, and that the relay reports not just ON/OFF but also voltage on BOTH SIDES of the relay, which is super useful to keep track of what is going on.
For around $175.60 USD at the time of this article, that is an excellent deal. A 500 amp battery on/off switch could cost from $50-80, and a NMEA 2000 voltage sensor could be $100-200, along with a remote controllable relay, which I can't find decent pricing on at all.
Even if you aren't going to use the relay, having the voltage reported onto your NMEA 2000 network for your various start or other accessory batteries is well worth the $175.60 in my opinion.
Video review of the NMEA 2000 Relay
Unboxing and Setup
In the box you get the relay itself, a single piece of paper that allows you to access the install guide, and a set of labels. I like how Egis uses boxes for all of their packaging and not plastic. Not only is it easier to get open, but far more recyclable.
Lots of choices with the labels. For the multi relay/switch products, this is essential.
The relay itself has a cover over the two studs, and the rest is all one piece. You have the big ON/OFF yellow switch, a status light in the upper right, and two cable bundles - one for NMEA 2000 and one for the connector for remote switches and negative power.
Installation
You can find installation instructions by scanning the yellow QR code in the packaging - another great way to save on printed crap that, while you might read during install, is just a waste of resources. It will take you to this PDF which has a lot of good detail in it.
Installation is pretty straightforward from the physical side of things. 3 screws to attach it to a surface, get your big wires onto the studs. For the NMEA 2000 connector, it's as easy as adding a drop cable to get to a tee and plugging it in.
However, you're not done, and this is the only negative I have (you'll get the joke) with the product in general. The NMEA 2000 interface needs power to work, and while it can get the positive side of the power it needs from the batteries that are connected, it needs a negative as well. The provided connector doesn't come with a matching plug and set of bare wires, so in my install, I had to cut the black wire and wire it up separately. Note that a 7.5 amp in-line fuse is required on this wire, which is also not supplied.
Given that the intent in purchasing this unit is to likely put it on a NMEA 2000 network, it would have been nice to see all of the required components provided to do so, but for the price, I can't complain too much.
This connector also houses the wires for a remote LED, if desired, and the ability to connect in a remote physical switch as well.
Generator and Main Engine
Part of my power project led me to need to move around some of the battery on/off switches on a panel in the engine room. I decided to look at replacements that were about the same form factor, but a bit more updated. That led me to the Egis XD Single relay, and I stumbled across the NMEA 2000 version, which was even better.
I also wanted to be able to more accurately monitor the voltages of my generator and main engine banks. Previously, I had used the secondary voltage input on a Victron shunt to monitor the start battery, but the generator battery was monitored by an expensive 3rd party monitor that eventually failed. The Egis relay allowed me to get that monitoring directly at the switch point, saving additional wiring and complexity.
AGM Bank
As part of my new power system, I have an AGM bank that serves as a backup house bank and emergency dumping ground when BMSs or alternator regulators misbehave (which has already happened). I'll cover more around why I have this in the upcoming article on the power system design, but setting aside the why, I wanted to have a way to turn it on and off for a couple of reasons.
First, I don't want the AGM bank to be used for house amp hours while sitting at anchor or at the dock. Second, I wanted to be able to automate turning it on when the engine was started, thereby providing that dumping ground for alternator and BMS foolery. The NMEA 2000 connectivity is a perfect way to do this, and it works extremely well.
For the first few weeks, I did this manually using a virtual switch within my Maretron N2Kview display at the helm. In my startup check-list, I turned the bank on before I started the engine. I reversed the process when shutting down, turning it off. But it became yet another step that I could screw up (and I did several times) so I decided to automate it.
I decided to use Node-RED, an automation tool (woefully underselling it here - it's so much more) that you can use to do lots of fun things. I chose to run it on my Signal K server instead of my Victron Cerbo, as my experience has been that the less you do on the Cerbo, the better it can handle everything else. Yes, I do have Node-RED stuff running on the Cerbo, but it's Victron-specific, and part of the power project will cover several automations I have in place there.
This automation is pretty simple. It watches for RPM data on my NMEA 2000 network, indicating that my engine is running. If it sees that data, and the RPMs are 500 or above (my engine idles at 600 RPM) then it turns on or closes the AGM Bank relay, unifying that bank of batteries with my LiFePO4 bank and providing both a redundant battery in the case of BMS issues, and a place for alternator amps to go in the case of problems.
Using a heartbeat node, as some engine monitors still have Hz and an RPM reading well after shutting off, it determines when the engine is off and turns off / opens the AGM Bank relay. This ensures that bank is not touched while on battery power or at the dock.
The downside to this setup is the charge profile for the LiFePO4 batteries being used for the AGM bank, but that's something I'll cover in more detail in the power project series.
This automation has been working flawlessly for months. I still have a manual switch on my helm display, and it shows green while underway indicating that it is working. I still check it to ensure it's on, but now I don't have to remember to turn it on or off. Win!
NMEA 2000 Details
The NMEA 2000 setup is pretty easy once you have it plugged into your network and powered appropriately.
There's a diagram on the back of the unit showing DIP switch settings. Not only can you choose the instance information, but you can turn on and off reporting for each of the stud connections, which is pretty darn cool! This means you can see the voltage on both sides of the connection, which can be helpful in some situations.
Being able to quickly make changes without software or other tools is a great feature. Having worked on tons of boats, having to haul out a laptop to do something simple is super irritating, especially in hot, less than computer-friendly engine rooms. In the example above, I'm only reporting voltage on the second stud with the final dip switch in the up position.
Maretron N2Kview showing transmitted PGNs
The useful PGNs that the relays transmit are:
- 127501 - Switch Bank Status - this is what shows the state of the switch and allows for it to be manipulated
- 127508 - Battery Status - this shows the voltage at one or both studs
Various displays and MFDs can of course control the relays via NMEA 2000. I've also put the voltages for both studs on the displays so I can see the difference, and when one is off/on.
In the case of the AGM Bank, because it is only used underway, the "Far" side (lower voltage value above right) sometimes drops over time if it hasn't been used in a while, although not to anything below 13V. It's a handy way to see it easily, though, and I have alarms on both sides just in case things are too low/high.
Here's a similar view to the above but in Maretron N2KView with the battery voltages and switches.
And here's what it looks like when you have one of them off with a starter (the main engine) on one side, and the battery on the other.
Wrap Up
So far I have not had any major issues. The AGM Bank cycles on and off every time I get underway, which is a lot this year so far (110 trips and over 2500 miles).
The generator and start banks don't get cycled on and off that often, although I've considered automating the main engine bank in the same Node-RED automation that I am using with the AGM Bank and shutting off the main engine battery bank 60 seconds or so after I shut off the engine. We'll see.
More importantly for these banks, I am able to monitor the voltage accurately and track it historically to watch for bad trends. Everything is logged via Signal K to an Influx database, and I can look back on things using Grafana. I also have high and low voltage alarms set just in case. I can also shut the banks off via virtual switches at the helm if I want, or lock them out while doing maintenance in the engine room with the physical switch.
Nothing has failed, and nothing has really gone wrong, which given the complexity of these products, shouldn't be surprising, but it is nice when boating stuff doesn't break silently while you're sleeping.
I highly recommend the Egis XD NMEA 2000 relays. If you need to be able to control battery banks or other high amperage things remotely via NMEA 2000, or you want to monitor voltage remotely for similar banks, they are a great deal and easy to install.