Switching off power to Garmin reactor 40 autopilot

P

pcg

Member
For those of you that have the Garmin Reactor 40 autopilot with a helm control (GHC 20 or GHC 50), do you have a means for turning it completely off?

I'd like to be able to eliminate parasitic draw when I'm boondocking. I'm poring over the GHC 50 manual and there doesn't seem to be a means of turning the Reactor 40 completely off from that device, although you can program it to go into SLEEP mode, and the GHC 50 will be off as well anyway when boondocking.

I was originally thinking I would power the Reactor 40 from a power bus that all other electronics receive power from, and have a switch at the helm to shut off power to that bus. However, the Reactor 40 power cable requires a 40A fuse so I would need a relay if I wanted to shut it off from a switch at the helm. The problem is a 50A relay draws 3A just from coil current. I know the autopilot averages considerably more than that when in use, but I'd sure like to avoid another 3A when underway if I don't need to, particularly during long periods traveling at displacement speed when the outboard alternator is not producing a lot of current. So how are you turning your autopilot completely off when not underway?
 
You could use a panel mount breaker like a Blue Sea System 285 series rated at 40 amps. They include a manual switch to open them and a reset lever. This could replace the 40 amp fuse as well.
 
I don't have a Garmin Auto Pilot, but I do have a Raymarine. I actually replaced my entire 2005 Raymarine electronic system with a modern system including the auto pilot last year. Electrical draw when boon docking is something that I have not considered and I don't have an answer for the Garmin. But I do have a thought. I like to keep a system change like this simple. You might be able to get a toggle switch that you can mount on the helm connected to the power cable and simply switch the power off when the auto pilot is not in use. Your fuses could be separate from the power switch so that the system is still protected while in use. I have solar panels that add some power to my batteries everyday, so I don't worry about a little bit of draw, using the radio, lights etc when I am boon docking.
 
Karl Konecny":1zkbkx22 said:
That can work but the challenge is finding a toggle switch that is rated for the 34 amps peak draw of the auto-pilot
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Switch and a relay will do this nicely.

However, it seems that the system has two power connections. One for the pump and one for the electronics. I doubt that the electronics actually needs 34a.

If you are really concerned about the parasitic draws you'll want two cutoffs. However, I don't think the pump will draw any current if the electronics are off, so only one may be necessary.
 
Karl Konecny":2odbczis said:
You could use a panel mount breaker like a Blue Sea System 285 series rated at 40 amps. They include a manual switch to open them and a reset lever. This could replace the 40 amp fuse as well.
Click to expand...
A breaker to turn off a power bus that controls all non-essential electronics with parasitic draws makes sense. i’ll have solar, but won’t always have sun, and then amp-hours become precious.
 
ssobol":3x7ddznq said:
Karl Konecny":3x7ddznq said:
That can work but the challenge is finding a toggle switch that is rated for the 34 amps peak draw of the auto-pilot
Click to expand...
Switch and a relay will do this nicely..
Click to expand...
Yes, but the relay itself draws 3A, and I was just trying to avoid that. I’m concerned about spending lots of hours moseying along at displacement speed and not making much current from the alternator, but still using a lot of it for refrigerator and other things. But it’s likely at those times I’d have the autopilot off anyway. I’m speaking from inexperience, not having ever done this before.
 
I have the Garmin Reactor 40 with a GHC 20 and the smart pump. I run the power for the Reactor 40 & pump off the Windlass's positive post where the main wire connects (Works great since I'm not using the autopilot and the windlass at the same time! :wink: ) The 40 amp fuse for the Reactor 40 & pump is inline just off that post. That main wire comes from the battery through a breaker. It's one of those switch type breakers. Like this: thermal_cb.jpg
The power for my GHC 20 comes from the NMEA 2000 network, which is switched on my main switch panel. It's my understanding that when the GHC 20 is turned off, there is no power drain at the Reactor 40 and Smart Pump. That being said, I believe if pulling the 40 amp fuse is not preferred or easily accessible, installing one of those switched thermal cb's as shown in that photo above would suffice. In fact, my previous 22 had that set up just behind the helm seat for completely disconnecting the windlass. (There was also a thermal cb back at the battery's as well.) Colby
 
colbysmith":dmxxjh9c said:
... It's my understanding that when the GHC 20 is turned off, there is no power drain at the Reactor 40 and Smart Pump.
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That would solve the problem if that's the case. I'll call Garmin on Monday and ask. Thanks.
 
If you want to use a relay with no or minimal power draw, a Latching relay, will have minimal if any current when engaged.

On my auto pilot, I have used a push on and off switch rated for 40 to 60 amps. A 40 amp manual breaker will do the same.

Or you can use a small switch on the electronics to the circuit board of the "brain" and leave the power intact. Many auto pilots run a separate circuit to the hydraulic pump. The 40 amps is max load--most of the time the load is only a few amps. All of this depends on the load on the steering mechanism. A tiller steered 30 hp outboard, would be a lot less than a 62' sailboat.
 
A honda 90 at idle puts out 35 amps to the battery. You or worrying about a none problems. many of the newer motors in this size range put out even more due to the high amount of electronic on boats today. bass and walleye fishing drive most of the tech requirements in these motors today. Mercury puts out Alternator amp / Watt 60 amp / 756 watt (Belt-Driven)

I idle on the 225hp main or the 15 hp kicker all day running radar, 2 depth finder, 2 vhfs, at least 2 cell phones, nav lights in the morning and fog and 2 cannon electric down riggers with 20lbs balls set on bottom follow ( going up and down all the time) and have never been low on juice. Yeah its a none issue not worth thinking about.
 
starcrafttom":3ujf3j31 said:
A honda 90 at idle puts out 35 amps to the battery. You or worrying about a none problems. many of the newer motors in this size range put out even more due to the high amount of electronic on boats today. bass and walleye fishing drive most of the tech requirements in these motors today. Mercury puts out Alternator amp / Watt 60 amp / 756 watt (Belt-Driven)
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Wow, yes that changes everything. I was under the impression these motors put out far less at low RPMs.
 
Several of us who are active in this thread, Were active in a similar thread almost 2 years ago.. Tom had emailed Honda with a question about his outboard.

According to Honda specs for 2006 and before, the Honda 90 puts out 16 amps from its "alternator". When the change to EFI occurred about 2007, Honda 90's put out 44 amps and 35 is available for charging. However I doubt that much charging is available at idle.

To put this question to rest, some one only needs to use an IR thermometer to determine the alternator temperature at different speeds. Also use on the shunt monitoring devices, such as the Victron 702/712 or just the victron smart shunt. to determine exactly how much output available is for charging for your motor The shunt needs to be in series with the motor ground (Negative) and to the battery being tested, and that battery needs to be discharged significantly so that you do measure the full output. I apologize, but don't have a Honda 90 to test.

If you have the pre 2007 Honda 90 you will not have a lot of power available.
You can easily test the amount of current draw of each instrument which you are concerned about.

If you want to bring your boat to Hontoon, or make a side trip to my house before or after the gathering, I have the test gear and will be more than happy to do these tests. This is the only way to find the answer to your questions, which have not been resolved in the last 2 years.

Here is a link to a knock off of the Victron 702, which have used for several years and seems to work well.

I can briefly touch on this during my presentation at Hontoon (the topic of the primary presentation, is "Sealants, adhesives; resins and types of laminates/cores used in fiberglass boat construction.")

I will bring the shunt meter, and an IR thermometer if anyone wants to "donate" their pre 2007 Honda 90 for us to do non destructive testing upon at Hontoon.
 
On my '08 BF90D, it needs to be above ~1K rpm to get high amps out of the engine to charge the battery. At true idle the available current is much less.
 
It may be less at idle but how much do you need. I run all of those items, radar and downriggers being the most power draw, plus a fridge on a different battery but charged by the same motors, and never had a low battery. Never not been able to start my 225 main after 8 hours of running just the kicker and all those items. This is just an none problem. Sure it would be neat to know but its not useful to turn your auto pilot from stand by to off over 3 amps???????.

Now amp use at anchor.. that is well worth talking about but still not a major problem if you travel every day as we do. I have run the heat and the fridge for 3 days without draining the battery past not starting the main. which brings up a good point. make sure your kicker has a alt and a pull start. You will never be stranded due to low voltage.

Also I do remember reading last years that some of the smaller motors , under 40hp and even kickers, where going to but out max amp at tolling speed just because of all the power draws on modern bass and walleye boats. cant remember where on the www I read it but makes since with the direction of fishing.
 
I agree if running a decent speed, the alternator will keep batteries up. Our most recent experiences was with the Honda 150, about 35 amps available for charging. We ran the 30 amp Sterling battery to battery charger, and charged in the 25 to 30 amp range (measured on viltron 702, when we were running each day (2500 to 5500 RPM). Our house batteries were also well charged. The Li bank was running 2 chest freezer/refers, a microwave and induction burner. (Average 100 amp hour or so a day, out of a 200 amp hour Li bank.

I had made assumption that "pcg" was including anchoring--and consumption over at least a 24 hour period. However it would be very useful to have some more specific information--and too bad the outboard manufactures don't give hp/torque, fuel use, and alternator output / RPM in the brochures.
 
PCG asked about slow speed travel, I had to read it twice. which is weird because that is when I would like to run my auto pilot the most.

This is like a on going argument with a friend of Susan's. Susan would run the heat in here toyota with the windows half way down and her friend would chastise her for , I shit you not, adding to global warming... No matter how many people explained to her that if the motor is running then the heat is being created and it does not matter that the heat is going out the exhaust or thru the heater core and out the window. She could not grasps the idea and continued to chastise Susan for it. Cal state collage graduate and she new better.

So as long as the motor is running I really don't think you can run enough electronic ( other then a microwave) that would drain your battery faster then its being charged and it sure as hell is not 3 amps making or breaking the system. Hell we run shrimp pots for 3 10 min cycles back to back along with ever thing else and they draw 25 to 30 amp when running. Do that every hour.
 
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