Battery/Electrical Troubleshooting

[Mickeyrouse]

I am having a real hair-puller. Somehow I am not getting enough juice to start the engine, a Westerbekek(Isuzu) 55 Four C. Even though the battery charge state per Link 1000 indicates charged (probably out of calibration) the panel voltage meter shows 13.2 volts or better, as confirmed by my Fluke 73, the engine barely grunts. A few minutes on the Truecharge 40 will spin it right over, and she fires right up. Yet the charger has been on overnight, which, to check the charge state, I will disconnect before starting attempts. I have three banks: house, (4 110 amp group 27) and separate engine banks, 110 amps each. All Banks can be switched to run in parallel to provide 660 amps.
My Fluke clamp meter says I'm getting 20 amps or better on each output of the Truecaharge. I have cleaned all terminals and added a film of dielectric grease to terminal surfaces. I have equalized several times. Engine charging seems to be healthy, having had the alternator (Balmar) checked out in an alt. shop. Engine batteries charged via Balmar digital duo-charge. All cable for starting/feed is boat cable, gauge 1/0. Wiring throughout the boat is less than three years old. All cable runs are fused. (is meter shunt deteriation a possibility?) System worked fine upon original completion of job, but began to act unreliable about a year ago.
After engine has started and come up to temparature, will start easily as long as it is just a little warm.
Have followed Nigel Calder's troubleshooting sequnce for ground leaks and shorts, and everything is okay. Except it's not.
Where do I go from here?

[cal40john]

I think the next step is you need to do a load test on the battery. A bad battery can be charged and hold a good voltage, but has no capacity left. Basically look at the battery voltage under high load, with a load tester or cranking engine with fuel stop pulled. Link below suggests anything under 10 volts you need a new battery.

Some load test options:
Battery Testing, Maintenance And Myths

John

[btrayfors]

John's right: you probably have a bad start battery. They can exhibit a high state of charge and accompanying voltage, but still have lost virtually all their capacity.

By the way, this is the USUAL CASE with car batteries. They begin to lose capacity when they leave the factory. Over the years, they continue to lose capacity until that one morning when they can't start the engine.

Nothing mysterious here. Load test or, better, replace your start battery.

And, for the umpteenth time: A HIGH VOLTAGE AND STATE OF CHARGE SAYS NOTHING .... NOTHING AT ALL ... ABOUT THE REMAINING CAPACITY IN THE BATTERY.

Bill

[sailorboy1]

When you try to start and it doesn't does the starter engage but doesn't turn fast enough to start the engine, or does just nothing happen? If nothing happens you most likely have a corroded/bad connection in your start circuit which the little extra charge manages to be enough to overcome (for now). When I had the same problem a couple of year ago it was the starter wire corroded in the engine harness and I had to put a jumper around it.

[Mickeyrouse]

I load-tested the main engine starting battery over a week-end. It checked out. At the same time I bought an additional new 110 amp starting battery, built new reinforced box, added additional heavy duty disconnect switches, and this became engine bank 2. Little to no difference with bank 1, 2, 3 or any mix of 2 of the 3, or all 3 together. Which makes me think "wiring", which I checked out. Still the same.

[Mickeyrouse]

Oh yeah the starter motor engages, grunts, turns half-heartedley a couple times, almost starts, but usually doesn't until a few minutes on the charger, then it's happy as a clam. Does same trick on new battery and not so new but load-tested battery.

[cal40john]

Originally Posted by Mickeyrouse

I load-tested the main engine starting battery over a week-end. It checked out. At the same time I bought an additional new 110 amp starting battery, built new reinforced box, added additional heavy duty disconnect switches, and this became engine bank 2. Little to no difference with bank 1, 2, 3 or any mix of 2 of the 3, or all 3 together. Which makes me think "wiring", which I checked out. Still the same.

Could be the starter motor in that case. On the off chance that it is engine related, measure the the current that the starter draws when trying to start the engine. An engine that has a lot of resistance will cause the starter to draw a lot of current. You'll need to compare with what is normally expected of your engine and starter.

Discovered that with my first poor attempt to rebuild a car engine at age 16. Could only start by popping the clutch going down a hill. Car repair guy looked at current draw and said to me, just rebuilt the engine and got the bearings nice and tight did you?

[Mickeyrouse]

That's the thing that keeps me from sleeping. Inaccessibility does not mean it shouldn't be checked, but it means it probably won't be checked. This is textbook inaccessible. I can't touch the terminals with my fingertips, and besides they are covered with protective rubber boots. So checking ( and removing/ replacing?) will come only with engine removal. Open heart surgery has more appeal. As you can gather, I want to make absolutely positively sure that all other potential causes have been investigated and cleared. The engine only has 250 hours on it, but I know that somettimes they can be bad out of the box.

[Ex-Calif]

Originally Posted by Mickeyrouse

That's the thing that keeps me from sleeping. Inaccessibility does not mean it shouldn't be checked, but it means it probably won't be checked. This is textbook inaccessible. I can't touch the terminals with my fingertips, and besides they are covered with protective rubber boots. So checking ( and removing/ replacing?) will come only with engine removal. Open heart surgery has more appeal. As you can gather, I want to make absolutely positively sure that all other potential causes have been investigated and cleared. The engine only has 250 hours on it, but I know that somettimes they can be bad out of the box.

Not very pretty but try shorting the starter solenoid secondary posts rather than using the starter button. The "emergency method" is an old screw driver that you wont mind having a weld spot on...

I suspect failed/corroded starter solenoid secondary posts. Could be as simple as changing the starter solenoid.

Make sure the connection to the starter solenoid secondary post is also clean and tight first.

Another thing to check is the condition of the cable from the battery to the starter solenoid. I had one that looked good on the outside but was almost completely failed. When opened up it was green with corrsoion. One indication is the cable will be soft and pliable rather than the fairly stiff condition of new cable.

[cal40john]

I think he's saying he'll be able to reach the starter to try that after the engine is pulled.

Originally Posted by Ex-Calif

Not very pretty but try shorting the starter solenoid secondary posts rather than using the starter button. The "emergency method" is an old screw driver that you wont mind having a weld spot on...

I suspect failed/corroded starter solenoid secondary posts. Could be as simple as changing the starter solenoid.

Make sure the connection to the starter solenoid secondary post is also clean and tight first.

Another thing to check is the condition of the cable from the battery to the starter solenoid. I had one that looked good on the outside but was almost completely failed. When opened up it was green with corrsoion. One indication is the cable will be soft and pliable rather than the fairly stiff condition of new cable.

[Mickeyrouse]

Update : I have since observed that the battery cable to the starter motor is getting pretty warm (cable has 250 amp circuit breaker on new 1/0 boat cable, pretty heavy stuff) and that the starter motor gets pretty warm. A buddy (thanks, Doug) got the starter out. Took it to an alternator shop, who pronounced it okay. Terminals on cable to starter appear to be good, not loose wiggly, or defective. My buddy Doug has a megger which we will use to check the cable for integrity, but since the terminals appear snug and tight don't expect to find much there. What now?

[sailorboy1]

Normal starting should not result in the cable and starter getting "pretty warm".

How long is the cable from the battery to the starter? Maybe you just need bigger cable. You say the cable is new was it the same size before? Is it kinked somewhere that could have broken some strands.

Tha megger on the cable wouldn't tell you anything, it only needs a few strands of wire to megger OK and it has this or it would never start.

Check the ground wire connection and wire on the engine back to the battery also.

[Cruisingscotts]

Tight connections are not nessesarrily a garruntee of good continuity. Scale or corrosion on a terminal connection can be present even if the connection is tight. A good trouble shooting tool is a IR heat gun therm. You can shoot all the connections when someone is rolling it over, more practical would be to undo clean and sand all of your connections reconnect with a little copper anti seize. Another culprit could be the start relay coil if you have one. If the contact in it is getting worn out it will make lots of heat, really cheap to replace.

[Mickeyrouse]

Battery cable at 1/0 ga. Is same or larger than original builder installation, better grade, and terminals shiny clean.

[sartorst]

I dont have the time to explain voltage drop at the moment but is very easy when you under stand it this will pinpoint the problem if it is a poor connection cable sizing and all
google voltage drop testing!!!