another newbie thread on 24v setups

I am not exactly a newbie to boating but am new to 24v systems. Long story short I just bought a boat that I know nothing about. Lowe 170W with a Johnson 50. It has 2 batteries(1 deep cycle and one marine starting) for the trolling motor and a marine starting battery for starting. The trolling batteries are wired what appears to be parallel at the posts but into what looks like a plug & receptacle setup just like at the front where the trolling motor plugs in. I am not sure what all is happening where this plug is wired in because I am reading 18v across either battery...which leads to my main question. What should the batteries read voltage wise? I had it in my head I would still only get 12v at the battery and that much higher would damage a normal 12v battery. I have no idea what the trolling motor is set up for. Its one of the Evinrude models and the bottom plate has been removed so there is no data whatsoever. I know it will only run if both batteries are connected so I assumed 24v. I am pretty sure the previous owner was even less knowledgeable as he had the cranking battery wired into this too when I got it. Apparently he was trying to charge all 3 off the 50s little charging system

Re: another newbie thread on 24v setups

This is a 24 volt system and is two batteries connected in SERIES -- not parallel. You should measure 24 volts from this sytem unless one of the batteries is bad. Just so you know, you are running a deep cycle and a starting battery in this system which is not a good setup. Both batteries in a 24 volt system should be the same type and size.



This is a 12 volt system using two batteries connected in PARALLEL -- not series. Two batteries in parallel still provide 12 volts but double the capacity. You cannot get 18 volts from this system. Only 12 volts. In either of these systems there should only be two wires going to the troller receptacle up front. You should measure either 12 volts or 24 volts across the two terminals. NOTE; If the troller foot pedal has a 12/24 switch you have a troller that is capable of running on either 12 volts OR 24 volts. That takes totally different wiring and will have three or four wires from the batteries up front. To go any further with this you need to figure out what you have.

Re: another newbie thread on 24v setups

Yes, I am familiar with series and parallel wiring. The problem is where the wires run into the plug you cant tell whats going on with the connections. Its run into a plastic housing and goes from the 4 battery wires into the 2 wires that run up to the front trolling motor plug. It is wired to have a +/- run off each battery appearing to be wired parallel & 12v at the batteries. Problem is like I said it reads 18v at each battery just checking from + to - on each one. Wouldnt this mean the connection would have to be wired in series inside that housing? Or maybe inside the trolling motor itself? Keep in mind this boat is brand new to me. I have never put a charger on the batteries or anything. I literally bought it, noticed the wiring was goofy, tested it with a voltmeter & posted my findings here. I am just trying to figure out exactly whats going on before going further so I dont damage anything. I plan on buying all new batteries after I get it all straight but not before I dont know if I am explaining this very well or not, lol. Thanks for trying to decipher my rambling! So if it were wired 24v and charged with good batteries I should get 24v checking + to - on each battery?

I got to take it out this morning for the first time and apparently have a rectifier problem too. The tach & speedo dont work and its charging to almost 15v. The depth finder at the helm was having problems. It would come on but wouldnt read right. Didnt read anything but zeros for depth, temp and speed at first. I reset it & it read for about 15 seconds and them wouldnt refresh. I hate electrical problems. At least she ran out good and everything else seemed to work right.

Re: another newbie thread on 24v setups

I may need to clarify because I may be confused and wrong...instead of running the + & - cable from one battery to the other & then from the second to the trolling motor each batteries cables run to where the 4 wires tie in to the 2 wires. That would still be parallel right? Mine looks more like this if you can grasp my crude diagram here haha...

=>- +

=>- -

only with a plug receptacle wired into the splice/joint of the 4 wires & a plug on the end of the 2 wires. didnt know how to put them in

Re: another newbie thread on 24v setups

Luckily I found the data plate for the trolling motor. Unfortunately I cant find any info on it. Its a model BF4PH. 99. Any ideas where to look. It doesnt appear overly large & if I had to guess I'd say maybe 40lb thrust. I wouldnt guess it to be a 24v. If it is its the smallest I have ever seen. I also took a couple pics while I was out there...
http://i3.photobucket.com/albums/y93/MetalMama6/DSCN0650.jpg
http://i3.photobucket.com/albums/y93/MetalMama6/DSCN0653.jpg
http://i3.photobucket.com/albums/y93/MetalMama6/DSCN0652.jpg

Thanks a ton for looking at all this for me. If I have to take it to a shop I'll probably end up divorced You guys know how wives are...

Re: another newbie thread on 24v setups

Can't tell squat from your rambling description. Pictures of the inside don't tell us anything either. Why not show us some pictures of the wiring instead since that's what is confusing you. As I mentioned, does the foot control have a 12/24 switch on it. Is there one on a panel at the bow of the boat. Is there a 12/24/Run/Charge switch up there? Details, details, details. You have a 12/24 volt system -- at least that's what it started out as. If someone has butchered it we have no idea what you have now. Some boat manufacturers (primarily bass boat builders), had their head up their proverbial rear ends when they designed the wiring systems but basically here is what you have. Some motors were designed to operate from EITHER 12 OR 24 volts. Since you can't do series AND parallel wiring at one time, they added a switch panel at the bow of the boat. Trolling motors may also have had a 12/24 switch,. So there were two ways to do the 12/24 thing. One way was to run two wires from each battery up front to the switch panel. From the switch panel there were three wires to the foot control. From the foot control there were three wires to the motor. Ground, 12V, and 24V. The second way was to wire the batteries in series at the batteries. Then a third wire was added at the jumper between the two batteries and it ran up front also. Again, three wires to the foot pedal, then three to the motor. If your motor only has two wires betwen the foot pedal and the motor you have EITHER a 12 volt OR a 24 volt motor. It cannot operate from both -- its one or the other. I suspect you have a 12 volt motor. Just join the two pairs of wires from the batteries (parallel), then match the two from the foot pedal to the receptacle and go fishing.