Bizzare Outboard Electrical Problem

[Adeline]

Went out on the Columbia Sunday and ran into a number of little problems. I've already posted about my leaky LED trailer lights. This problem here is the second of my hat-trick. The third is generator related and will be a separate topic. -1989 J70TLCEM- Installed a Blue Seas Dual Circuit Plus Battery Switch #5511E(Off-#1-Both) and Blue Seas ACR(Automatic Charging Relay) 7600 . With #1 selected, the two banks will be automatically connected when the voltage reaches 12.5. And disconnected(overvoltage) if voltage exceeds 15. The idea, when #1(starting) has recovered from startup duties, the relay closes and #2(house) gets hers. Electronics are on #2 and isolated. These settings are adjustable. It has worked splendidly until Sunday. I started the motor and quickly the #1 voltage spiked to 17.5+. I then selected "both" on the battery switch(make before break) to rein in the spike. The electronics blinked and the control box emitted a steady scream. This is the sound of an overheat condition(which I didn't have). I killed the motor. Returned switch to #1. Key on. Steady scream(motor still off). Selected switch to "both". Motor started normally with no alarms. Ran all day. Normal voltage on both banks. Charging normally. Tachometer normal. I occasionally stopped the motor and selected switch position #1. Key on, steady scream. Back to switch position #2 and all normal. I checked all battery connections(wingnuts, I know). They SEEMED fine. Does this sound like a defective battery, battery switch, or ACR ? Or should I more closely examine my wiring again ? Perhaps wire-wheel the #1 battery terminals ?

[Falco]

I would call Blue Sea. I wonder if the combination you have there is what you want. I believe (but don't quote me) that the 7600 does not require a battery combining switch - it does this on its own. See also that Blue Sea offers a combiner switch (like yours with a different ACR - see http://www.bluesea.com/product.asp?Product_id=230178 Maybe this is what you need?

[thataway]

The battery switch in "on" puts house to the pannels on the console and isolates the engine start battery to just the starting (and other circuits which come off of the engine harness). When you put the battery switch on "Combine" it allows all batteries to be combined--that is house and start, engine and pannel are all combined. The combiner does this--after the voltage reaches 12.5. I think that there is a little confusion about charging the engine start battery first. If you watch an accurate digital volt meter, the output of the alternator goes to 14.4 (or so) volts almost immediately--and as soon as the ACR senses more than 12.5 volts, it combines the start and house batteries. What bothers me a bit about this scenerio (and I am sure Pete also) is why the voltage went up to 17.5 volts. This is not a "Spike"--a spike is transcient. This suggests that there was a defect in the voltage regulation circuit--even the ACR is rated up to only 16 volts. (I don't know if 17.5 volts will damage it--but it may explain some of the other electronic problems--such as the alarms).

Since the engine started, I doubt if there is serious corrosion on the battery posts (but I would certainly clean all of the connections). The question is will an open circuit (like not connected to starting battery) would cause the voltage to go to 17.5. I suspect it is. But as soon as it is connected to any battery, the voltage should have dropped.

As for the battery switch. I prefer the off 1 2 all. This gives a bit more flexablity. I have two of the same ACR in the TC 255. I don't have them bypassed exactly the same ways--I have them so that they can be isolated by circuilt breakers or switches. I can bypass them, but don't.

What to do? I would clean all of the terminals, and apply conductive greasse/coating. I would check all connections and then take the volt meter and start checking with the engine running.

[mikeporterinmd]

Step one would be to turn off the switch and check the voltages at
the batteries. Low voltage could cause something like this. And
of course check the connections at the batteries. Hmmm...check
the voltage right at the ACR posts. With engine and charger off, the
ACR should be open, but double check that the combine light is not
lit for some reason.

My bet is something loose between the A post, where I assume you
have the main engine cable connected and the starting battery.

Mike

[Larry H]

Based on my years in the Evinrude repair business, I would hook the motor directly (no switches in the circuit) to a good battery, start and run the motor(fast idle not over 2500 rpm ) Measure the voltage across the battery and check for alarms. If the voltage starts off at battery voltage(12.5 or so) and then rises, the motor's charging system is probably OK.

Do this with each battery. Then you know that the motor, charging system, and batteries are not the problem.

I can't offer any advise about checking out the Blue Sea system, but knowing that the problem is not in the motor or batteries is a start. It is possible that one of the batteries is faulty.

The charging system in your motor produces a 6 or 9 amp constant output. The voltage will continue to rise unless there is a draw on the system. The factory recommendation was to put on running lights, stereo, etc., until the voltage stabilizes at 13.8 to 14.0. With that kind of charging system, monitoring a volt meter on the dash helps.

The Blue Sea combiner may not work properly with your charging system. If you talk to Blue Sea, tell them about your constant output charging system.

That type of constant output was used prior to about 1993 in the 70 hp, so newer motors don't have the same problem.

Hope this helps,

Oh, and tighten the battery wing nuts with pliers or a wrench, hand tight is not enough.

[flapbreaker]

Out of curriousity you might try switching the batteries and seeing what happens.

[mikeporterinmd]

[Larry H]

I reviewed the info on the Blue Sea site and here's my take.

The motor battery cables 'must' be connected to the start battery.

When the combiner senses a voltage higher than 12.5 on the start battery, it also connects the house battery to the motor's output. (combines)

If the voltage gets higher than the 'overvoltage setting' (15.0v) the devise disconnects the second battery only.

This over voltage condition is possible when charging with your outboard, but it will take some time for the 6 or 9 amp output to charge both batteries to that voltage. (Unless the batteries are fully charged to start with.)

The start battery will still be connected to the motor and the voltage of the start battery will still continue to rise unless more loads (lights,etc.) are turned on. Those loads must be connected to the start battery to do any good at reducing the high voltage. So if all your 'house loads' are connected to the 'house battery' and the combiner has disconnected the house battery from the charging circuit, then turning on lights,etc. won't do any good.

My conclusion is that this combiner won't work properly unless the high voltage disconnect can be defeated or loads can be applied to the start battery to reduce the voltage below 15.5.

The correct 'combiner' for your motor would be one that switches the charging output away from the start battery and to the house battery where you could then switch on 'loads' (lights,etc) to keep the voltage at 13.8 to 14.0. This would require rewiring your outboard.

The key to all this is that your motor is putting out 6 or 9 amps all the time and has no regulator. Once the battery is fully charged, the voltage will continue to rise and the battery will boil.

This is the reason that Evinrude specified wet cell lead acid batteries only. Gel cell or AGM batteries will be damaged by the high voltage condition.

A manual 'off-1-both-2' switch can do this combining, but will not be automatic.

Start the motor on battery 1(starting), then when the voltage is at 14.0 or so, switch to battery 2(house), or to 'both', and monitor the voltage manually.

For other readers...... THE ABOVE DOES NOT APPLY TO OUTBOARDS THAT HAVE A VOLTAGE REGULATOR!!!
Voltage regulated outboards should be able to use the Blue Sea combiner with out any problems.

Techs....Does the above make sense?

[Adeline]

[Adeline]

[thataway]

Larry H.
Makes a lot of sense! I had forgotten that those engines were max output 9 amp charging circuit. Bearing this in mind--the ACR (which does handle 60 amps seems a bit overkill...), but it still does isolate the house battery on starting (when both low voltage and voltage spikes occur), and act as a voltage limiter. The switching voltages of the ACR's can be set to different levels, within a fairly narrow range. I also agree that the switch for combining should never be used to start an engine--that there be manual switches for that.

It seems as if you were using the ACR as a voltage limiter--which would protect the electronics from high voltage, but under some conditions might not allow full charging of the batteries.

I have owned outboards with charging circuits since 1957 and don't ever remember having a major problem with over voltage--but "way back" or in the dinghies, I never measured the voltage--just made sure that there was enough 'juice" to start the engine.

Also it is a reminder to run these engines on flooded lead acid batteries.

[Larry H]

Adeline,

I don't know if high voltage can set off the alarms. I never had that problem come into the shop, but I think its possible. It is possible for the voltage to rise to 17.5 or higher. The vro has an electronic alarm circuit attached to the pump. Does your control box "chirp" when you turn on the key prior to starting?

That is a check that the alarm works.

Do you have regular lead acid 'wet' batteries or AGM or Gell?

Those newer type batteries were specifically "not recommended" by the factory in the mid-ninetys.

I ran a 1991 Evinrude 70 like yours from 1990 till 2006. I always used regular 'wet' batteries. My 91 motor had a 6/9 amp charger. That is 6 amps nominal and 9 amps max at 5,000 rpm.

[Larry H]

Pete,

I checked the info on the switch on the Blue Sea site. NIce switch!

If you wired the switch correctly, I don't see that it could have any effect.

Putting the switch in the Combine position doubles the battery capacity which would reduce the rise in voltage.

Its almost like the start battery has too much internal or external resistance, causing the voltage to rise excessively.

You could try swapping the battery positions (or wires) and see if the problem changes.

Otherwise, I am out of ideas.

[Larry H]

Bob,

The electrics on our old skiffs were limited to starting the motor and maybe running lights and those boats were not operated like a modern C-Dory. As long as the battery water was kept filled, they didn't cause much trouble.

After reviewing the Blue Sea site, I see that the control and switching systems have been modernized to keep up with the proliferation of electronics and cabin amenities.

I like that Blue Sea 5511+ battery switch. It switches on and off the start and house batteries with one knob, and can combine the two when necessary.

[mikeporterinmd]

It's pretty small, too. One odd thing was some webbing that prevented
me from running wires out one side. However, I was able to cut
out the plastic pretty easily. Supposed to glow in the dark, too! I
haven't really checked though since we have a security light near the
boat.

Mike