# Electric boat dead in the water



## electricboat2 (Sep 21, 2008)

I'm hoping someone on this site may be able to help me. I have an electric boat that is constructed with what appears to be EV parts. It is a 36 volt system powered by 6 12 volt batteries. The batteries are new and I have recently checked each one individually and they all read 12.9 volts fully charged.

I have used the boat a few times with no problems. Full speed it draws 47 amps. I usually cruise at about 25 amps.

The other day I was cruising along at about 35 ams when the motor suddenly lost power. No noise or smoke or anything. The guage which shows me pack voltage and amp use indicated o.4 volts. When I turned the ignition off, the voltage read 37 volts. When I turn the ignition on (no power to the motor) it drops to 0.4 volts.

After a short paddle and a tow, I got it home and charged the system. It didn't take much power because the batteries were nearly full. The next day, out of the water, i turned the ignition on and the motor seemed to work ( only ran it for a few seconds).

I have since taken a voltage reading from ground on the controller to A1,A2,S1 and S2 on the motor and the readings were A1-38, A2-38, S1-18, S2-18. The motor worked.

I left the ignition on for about an hour with no load and the same thing happened, voltage on the guage dropped to 0.4 volts and the motor would not spin. There is usually a clicking sound from the controller when I turn the igition on but there was no click when it failed to spin the motor.

I checked the voltages in this state and they were substantially the same (S1 and S2 actually went up to 20V).

The motor is an Advanced DC XP1699 36/48 volt. The controller is a Curtis 1204-038 rated at 275 amps.

I don't know a lot about these systems but I am learning. Any assistance would be greatly appreciated.


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## Powah (Sep 21, 2008)

electricboat2 said:


> I'm hoping someone on this site may be able to help me. I have an electric boat that is constructed with what appears to be EV parts. It is a 36 volt system powered by 6 12 volt batteries. The batteries are new and I have recently checked each one individually and they all read 12.9 volts fully charged.
> 
> I have used the boat a few times with no problems. Full speed it draws 47 amps. I usually cruise at about 25 amps.
> 
> ...


It would take about 6 months to diagnose this problem over the web. I would contact a local friend or acquaintance with electrical diagnosis skills to resolve this problem. It should only take them about 5 minutes.

my 1st post! woo hoo!


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## 3dplane (Feb 27, 2008)

E-boat!
You say 36 volt system but it's 6 12 volt batts. Is that two in paralell and three of those in series? Reason I ask because what you describe sounds like a battery developing an internal open ones it's below a certain level.
You need to load test those batteries.Open voltage can be great but still zero amps under load.(like your volt meter showed) If that's the case but you have the above described battery setup( 2p-3s) that would mean two of those batteries are going bad (one buddy pair). If it's not bad batteries,it will be something silly like a bad connection,(wiggle and twist wires and connections), or tap on relays,contactors etc. Get a load tester first. Barna


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## electricboat2 (Sep 21, 2008)

Thanks folks. I realize it might be more than can be solved on this forum. I was thinking maybe my symptoms were common signs of either a bad controller or a bad motor. I will do a load test on the batteries. Although they are brand new (5 partial cycles) I could have got a bad one (or two).


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## elevatorguy (Jul 26, 2007)

Barna beat me to it, but it does sound like you are having a connection problem or battery failure. 
You could have high resistance in a connection at a battery, controller, motor or main contactor contacts.
If you can't find help readily, you could start with checking all the connections, disconnect and use insulated tools for safety.


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## TX_Dj (Jul 25, 2008)

I think Jerry and Barna are barking up the right tree here.

The "clicking" you're describing could be indicative of a bad connection in the pack.

I.E. once you start pulling some load, something somewhere is heating up, expanding, etc...

Gavin had a similar issue with his Tredia a while back, and it turned out to be a loose connection to the controller, which in its "clicking" had arced enough to melt down the nut and washer that should have been holding the connection tight.

Do be sure you heed Jerry's warning though... USE INSULATED TOOLS... even just bridging the terminals on one battery with a wrench is enough to turn it into a plasma ball.


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## electricboat2 (Sep 21, 2008)

The "clicking" I hear when I turn the key (when it is working) sounds like a good thing. It always did this when it worked properly. What I have noticed while I have been observing it and investigating is that once the key is turned and i get the "click" it works for a little while but even if I don't run the motor and it just sits with the ignition "on" after about 15-20 minutes, it goes dead.

So what I'm thinking is that whatever it is that goes "click" when I turn the key to the "on" position may have a problem. So can anyone tell me, in an EV, what does the key do? What does it activate so that the system will operate when it is in the "on" position? Perhaps that thing is turning itself off or overheating.

The reason I'm thinking it might not be the batteries is because the problem seems to be independent of drawing a load and, when it happens and I turn the key "off" the batttery pack reads fully charged (36+ volts).

Gotta find the darn "clicker"

Any ideas?

PS. Are the voltages I was reading at A1,A2,S1,S2 normal?


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## electricboat2 (Sep 21, 2008)

I think I may be getting somewhere. When I first got the boat, I found a "component" in one of the storage bins. It is an "Albright DC88-6". It looked like it was burned out because it had some black residue on the contacts. I didn't know what it was. I have now looked it up and find that it is a "controller" which is likely the thing that goes "click" when I turn the key on.

So, if I have one possibly burned out spare controller, I'm putting my sherlock cap on and thinking that maybe I've got another controller problem. Does anyone know if a sick controller would turn on and then turn itself off after a few minutes? If so, might this indicate a bigger problem somewhere else?

I will have to contort myself somewhat to find the controller as it is tucked back in a small space.

Also, in response to the previous response, I do have 6 batteries, 3 in series and 2 parallel. They are US battery 130 Ah.


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## TX_Dj (Jul 25, 2008)

The Albright DC88 is a contactor, like a giant relay. They go "click" but should only go "click" when engaging or disengaging, which is typically when you turn the switch on.

IIRC, the DC88 has a 24v coil, meaning it is expecting it's "on/off" signal to be a 24v source. If the control side of the contactor is being fed with 36v (nevermind the power it's actually switching) then perhaps the coil has a problem?

I got the impression from what you were saying before that it "normally" makes a "clicking" sound while in operation, as if it were repetitive. This shouldn't be the case.

Without knowing how your system is wired up, we won't know exactly what you're dealing with. Photos could be helpful.


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## electricboat2 (Sep 21, 2008)

The "extra" contactor says:

Type: DC88-6
Voltage 36 CO

I'll crawl inside and take some photos tomorrow after I buy a load tester and test the batteries.

Thanks for your help - and patience.


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## Qer (May 7, 2008)

One way to continue the diagnosis is to measure all the voltages when things stop working. First measure at the battery pack, then at the contactor, then over the controller and then over the motor. Somewhere along the lines your voltage will drop and there's your problem. Even if you don't know the schematics you can learn a lot by coparing the voltages when it's working compared to when it doesn't.

Make sure you're narrowing it down so you measure the voltage before and after a suspected component (ie a cable, the controller etc) until you know exactly where the power disappears. It can even be a washer or some oxide that ruins the fun for you, so it's easy to draw the wrong conclusions by working too fast.


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## electricboat2 (Sep 21, 2008)

I should change my post to "dead in the driveway".

I have done a load test and the batteries all check out fine.

I have also discovered that there appears to be another, smaller "contactor" in the system that likely powers the system. The Albright DC88 seems to be doing the job of switching from forward to reverse but there is another component tucked away that looks like a smaller version of the DC88. It is hard to get at it so I think I'll have to disconnect some wires and try to pull out the whole panel that these components are mounted on.

The problem I have with checking the voltages when things stop working is that I'm not really clear on how to do this. For instance, when it isn't working and I check the voltage between the ground and the A1,A2,S1,S2 posts on the motor, I read full voltage at A1 and A2 even though it doesn't work. So if 36 volts are making it through all this mess to these posts on the motor, I don't understand how I could not find that voltage elsewhere in the system.

But that is what I am learning. One day I'll have this figured out.

BTW, I live in Vancouver, BC. If anyone knows of someone around here that knows how these things work, I would happily pay for some skilled assistance. I just don't know where to look for someone with this sort of expertise.


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## 3dplane (Feb 27, 2008)

*Re: Electric boat dead in the driveway*

Looks like you have the batt+ to the motor. Lets go over to the controller side. Does the controller have three little push on connectors? If so one of them is (usually on one end) ignition input,it arms the controller.It should have batt+ voltage when key is on (or switch or alligator clip in my golfcart's case).Whithout it the controller will not arm. The other two is throttle input variable resistance (if you got one) on those you should see ohms changing when playing with the throttle.Measuring across the two wires.(usually from close to zero to 5000 ohm) Lets go from there.
Barna


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## major (Apr 4, 2008)

electricboat2 said:


> I have since taken a voltage reading from ground on the controller to A1,A2,S1 and S2 on the motor and the readings were A1-38, A2-38, S1-18, S2-18. The motor worked.
> 
> The motor is an Advanced DC XP1699 36/48 volt. The controller is a Curtis 1204-038 rated at 275 amps.


Hi eboat,

Coming late on this, but: Sounds like this is a series motor. You don't say what condition you took the voltage reading at. Be careful. You give the motor full voltage (top speed) with the prop in air, you'll overspeed the motor and damage it.

And by voltage from ground, do you mean relative to battery negative? In any case, 18 or 20 volts on the field of a series motor sounds bad. I suggest you disconnect the motor and power it from a single battery, 12 volts. B- to S1, S2 to A2, A1 to B+. Speed should be o.k. While it is running from the 12 volt battery, take the voltage on the As and Ss. Get back with that.

Regards,

major


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