Electric Downrigger Wiring and Performance

T

True Story

New member
I was hoping to generate discussion in respect to how people have connected their downriggers to their boats electrical system including performance issues if any.

I've had Scotty downriggers on our boat since new with fused, direct connections to the port and starboard batteries. Everything worked fine for the first couple of years. While I don't have devices on-board to understand battery voltage/charge, I made many multiple day fishing trips, fishing extensively without problem. I troll almost exclusively with the Honda 75hp with the battery switch set to "both".

Last year I had the original factory batteries replaced with AGM 55 amp hour batteries amongst other work performed by the shop and noticed on a subsequent fishing trip that the port side downrigger's retrieval rate was significantly slower than the starboard side. I'm not sure if they re-arranged the battery wiring schematic or not. I swapped downriggers to see if the problem was with the downrigger which it was not.

I'd sure like to get this problem figured out before my next fishing trip. Any thoughts or suggestions would be greatly apprectiated.

Thanks, Tim

ps. I will be purchasing a digital meter this weekend.
 
If it were me, I'd first pull the fuse on the port side downrigger and make sure it's physically clean. Then I'd follow that lead back to the battery and make sure that connection is clean and tight.

Don
 
TRUE STORY,
YOU ARE ON THE RIGHT TRACK GETTING THE METER.
CHECK THE CONNECTIONS FOR CORROSION CHECK THE WIRING FOR COROSSION IF YOU FIND ADDITIONAL RESISTANCE IN THE WIRING DON'T NESS AROUND REPLACE THE WIRING IF THE BATTERY IS BAD REPLACE IT THEN GO FISHING WITHOUT THE HASSLE OF DOWN RIGGER PROBLEMS.
 
I would think your problem is definitly a poor connection and/or corrosion. If you have your batteries selected to both then it seems it's not your battery. Because that should affect both riggers. I had similar problems on my defiance, because the batteries were in the bilge area and alot of salt water was flowing through there( faulty hull). My downriggers got slower and slower until one day I dug into the connections, sure enough all corroded. Even the wire was hit. I cut off the bad wire and put on new connections and voila, speedy downriggers again. But in your case maybe it's just the connection since it cropped up after changing batteries and only affects one side.

Sark
 
Don't forget the ground connections while you are at it. I've seen more DC electrical failures from poor grounds than any other single cause. Very common on Army Blackhawks operated in a salty environment like Hawaii. Also a good idea to spray your connections with something like Boeshield or Corrosion X after they are cleaned up.
Norm
 
Another little helpful hint taught to me by a factory rep from RayChem. (the people that make heat shrink tubing) If you are using heat shrink to cover connections. Coat the inside of the tubing before use with everyday contact cement. Let it dry. The melting point of the contact cement is just below the heat required to shrink the tubing. It will melt and provide a watertight seal around the splice. Much cheaper and just as effective as using the spendy connectors that have sealant in them. In addition There is a good reason that aircraft or marine grade wire is out there. The conductors are tinned. Using automotive grade wire is cheaper but you are asking for problems from corrosion coing on up under the insulation jacket and subsequent failures like Cutty Sark described. My advice is use the proper wire and connectors and you will have far less re-dos.
Norm
 
Wow! Thanks for the prompt replies. So, I'm not the only person that starts the weekend out by jumping on the site.

I'm actually excited about purchasing this meter. I bought a great book the other day called "Managing 12 Volts" by Harold Barre which has helped me at least to pull my head out of the sand so I can ask questions without sounding completely ignorant.

Seems to me that extensive use of downriggers adds a signficant element when considering 12 volt systems. During silver season when the fish are in, I might bring each one of them up 20 or so times a day. I realize I will able to determine the amp load after I get the meter, but does anyone know offhand what I should expect using a 15lb ball?

Another question I guess I should be asking is how many amps does my 16 amp alternator put out at idle? And, if the battery selection switch is set to "both", wouldn't the available amps be split for each battery? If this is correct, would it be better to connect both downriggers to the common post of the battery selector switch so I could draw from and more effectively charge one battery at a time as opposed to two? iiiiieeeeeeee. I'm really out on the limb now.

Thanks again. Tim
 
Go to Scottys' web site they list specs for their downriggers speed and amp draw with various weights. ex 15 lb ball is 8 amp draw if I remember correctly about 275 ft/min. Also look into a charging relay. I believe that they are avail at WM and at fisheries supply in seattle. Fisheries is I believe more reasonable than WM. (who isn't) It is made by blue seas and will protect from having one low battery drawing down the other. They are kinda pricey but well worth it IMHO. They supposedly protect from charging problems that can occur with different types of batteries. Without one my advice would be to only leave your switch on the "house" battery while using the downriggers and therby protect your starting battery from getting drawn down. A super source that I have found for a lot of questions like this is the whaler web site. (continuous wave/whaler) they have a forum on there called small boat electrical. Whaler owners are if anything more rabid than us C-Dory folks and have a bunch of good ideas re maint & modifications. I am planning on installing one of the relays when I change my manual scottys for electrics. Just havta finish paying for the new ETEC first.
Norm
 
Thanks Norm. I checked out Scotty's site and the downrigger draws 8 amps at 203'/min. I'll have to check out that other site you recommended. I'm going to have to get my calculator out but I'm thinking the downriggers don't use up as much power as I thought in relationship to the alternator.
 
My experience with Scotty riggers is that when you have a bad connection they get slow. First place to check is to take the battery terminal for the rigger off and clean it with a wire brush. Also look to see if corrosion has traveled up under the insulation (you can tell because the wire is larger in diameter than it should be). Then go do the next connection and repeat. Most of my failures were due to the Scotty Plugs. My fault as I didn't use their special grease on them the first year!

As for amp draw. I've run both my riggers for a full weekend without charging the battery. That was out at Sekiu and we were running them both up and down at least every 15 minutes all day long and quite often more frequently. Since my 7.5hp kicker isn't wired to charge the batteries on my sled this is the way I have used those riggers for 5 years. I've never yet had a problem with being able to start the motor after a days fishing on the trolling motor with my dual batteries.
 
here's some general electric motor troubleshooting tips fer ya. With any motor, the first thing to do is check the battery, if good, check the amp draw.
If the motor is drawing high amps, the cause of your grief is most likely due to a mechanical problem in the motor or related mechanical attachments or a short in the motor itself. Disconnect all mechanical atachments and test again, if it's still drawing high amps, you may be due for a new motor.
If the motor is drawing low amps, the odds are that you have some high resistance in the circuit due to corrosion or the brushes in the motor. Now is the time to go through and check all of your connections, this can be done by placeing the meter across (in parralel) the suspected bad connection and read the voltage drop while the motor is running. The meter should read zero volts, if you get more than .5 volts you have a crusty connection that is wasting .5v of juice. The beauty of checking voltage drops is that you can verify the problem and the correction.
Checking amps can be done a number of ways, if the anticipated amp draw is less than your multimeters rating, disconnect the motor and connect you meter in series with the motor wiring and energize the circuit, read amps. A better tool that doesn't require opening the circuit and potentially blowing the fuse in your meter would be an inductive amp meter. These can be purchased for less than $20 and just clip over the conductor and read the. A less accurate method would be to read the battery voltage while runnining the motor, if the voltage doesn't drop, you have low amps, if the voltage takes a hit when you crank over the motor, you may have high amps (must have a good battery). A quicker and even less accurate method would be to look at your cabin light, if it stays bright or dims when you turn on the motor.
Bottem line usually, high amps = bad motor. low amps = bad connections
 
Thanks again for all of your replies. I knew I should have made it to Jerrell Cove for BCK's Electric 1.01 class. I got my DMM on Saturday but other than check out the voltage of my house and a AAA battery I haven't had a chance to start poking at wires in the boat. Read mucho sucky weather!

I was also hoping some one would chime in regarding the pro's and con's of hooking the downriggers to their respective batteries as opposed to the common post or the battery switch or buss bar. The general perception I am getting is that it's better to draw from and charge, one battery at a time as opposed to two. Please don't ask me to elaborate!

Professor BCK. How would I go about better understanding how my Honda 75 HP engine alternator performs in respect to charging the batteries at an idle while trolling around?

Tim
 
Welll, one quick way would be to take your meter and stick the battery ( a healthy battery should read 12.6 volts)this is the open post voltage. Fire up the engine and watch the voltage as it runs ( the voltage should be at least ~ .5 volt over the open post voltage). Turn on your electrical goodies and the voltage should still hang in there at about .5v over open post. If the voltage reading drops below 12.6 at idle with all the goodies on, yer altercator anint altercating enough at idle. Bring up the RPM and watch your voltage.

A better solution would be to install an ammeter in the dash or cockpit so you could watch the amps trickling in, or, out of the battery at various RPMs and loads. In dash ammeters are relatively inexpensive.

wishin Iza fishin
 
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