Starter battery wired wrong?

[sunrise4]

I drained my house batteries on my SO 419 (built in Marion SC middle of 2016) to do a restoration charge (bank of 4 Firefly G31) and ended up with a bank voltage of 9.5 V.  I had intended to get to 10.5 V, but in the morning when I arrived at the boat the voltage had dropped to 9.5 V.  I proceeded to start the engine to start the recharge process, however the engine would not start even though the start battery was at a healthy 12.6 V.  I was able to turn on the power on the Yanmar B20 panel but it immediately gave me a low voltage warning and the engine start button did not work.  I was fortunate that I was at the dock and could connect to shore power to give the house batteries a charge through the onboard battery charger.  As the battery voltage started to rise I checked if I could start the engine, and around 10.5 V the engine started without hesitation.

I can't imagine that this works as intended.  Has anyone run into this same issue?

I have not traced the wiring yet, but I'm sure there is a way to rewire this to start the engine off the start battery with the house battery flat.

Glad to have discovered this at the dock and not at some remote anchorage in the middle of an emergency...

[j24sailor]

Aug 22, 2023 22:26:20 GMT sunrise4 said:

I drained my house batteries on my SO 419 (built in Marion SC middle of 2016) to do a restoration charge (bank of 4 Firefly G31) and ended up with a bank voltage of 9.5 V.  I had intended to get to 10.5 V, but in the morning when I arrived at the boat the voltage had dropped to 9.5 V.  I proceeded to start the engine to start the recharge process, however the engine would not start even though the start battery was at a healthy 12.6 V.  I was able to turn on the power on the Yanmar B20 panel but it immediately gave me a low voltage warning and the engine start button did not work.  I was fortunate that I was at the dock and could connect to shore power to give the house batteries a charge through the onboard battery charger.  As the battery voltage started to rise I checked if I could start the engine, and around 10.5 V the engine started without hesitation.

I can't imagine that this works as intended.  Has anyone run into this same issue?

I have not traced the wiring yet, but I'm sure there is a way to rewire this to start the engine off the start battery with the house battery flat.

Glad to have discovered this at the dock and not at some remote anchorage in the middle of an emergency...

Had something similar on our 409 with Firefly and we never did completely figure out what was wrong. Check the battery individual charge with voltmeter as our batteries were fine. I think part of the problem was we had a technician on board who had turned the main battery negative off, and our boat has a few electrical gremlins. Please keep updated. Thanks James

[Shaun K]

I have a SO419 that I purchased new about 4 years ago and day sail almost entirely out of Waukegan, 30 miles north of Chicago.
One of the house batteries died a year ago. She has 2 100 ah batteries connected in parallel and replaced the bad one. During this period while it was dying, I had seen the boat going dark and several unexplainable things happened. Even though I am an engineer and a life-long sailor, I could not figure out of had no patience to track the problems down.
One SAFE solution was to isolate these two batteries with a 1-2-both switch in the main battery compartment. I use both while charging on the dock and select 1 or 2 while sailing. While it's not an answer to the cause of the illogical problems with the way the SO419 is wired, it certainly gives me a comfort level to go sailing without the fear of losing the house batteries.
Another observation is that the panel voltage reading for the house batteries is almost always 0.5 volt lower than that at the battery terminals, most likely due to the wire sizes and where it is tapped at. The Engine and Thruster readings seem accurate, that leads me to believe the above lower readings for the house batteries.
I also carry a short jumper cable if tha starter battery needs a quick charge from other batteries.
Shaun
Wind Dancer

 

[zaphod]

Aug 22, 2023 22:26:20 GMT sunrise4 said:

I drained my house batteries on my SO 419 (built in Marion SC middle of 2016) to do a restoration charge (bank of 4 Firefly G31) and ended up with a bank voltage of 9.5 V.  I had intended to get to 10.5 V, but in the morning when I arrived at the boat the voltage had dropped to 9.5 V.  I proceeded to start the engine to start the recharge process, however the engine would not start even though the start battery was at a healthy 12.6 V.  I was able to turn on the power on the Yanmar B20 panel but it immediately gave me a low voltage warning and the engine start button did not work.  I was fortunate that I was at the dock and could connect to shore power to give the house batteries a charge through the onboard battery charger.  As the battery voltage started to rise I checked if I could start the engine, and around 10.5 V the engine started without hesitation.

I can't imagine that this works as intended.  Has anyone run into this same issue?

I have not traced the wiring yet, but I'm sure there is a way to rewire this to start the engine off the start battery with the house battery flat.

Glad to have discovered this at the dock and not at some remote anchorage in the middle of an emergency...

It is hard to say what caused your engine battery to discharge without seeing how they are wired. Did you have the engine battery switch turned off while you were discharging the house bank? If so, the only connection is probably the battery isolator that connects both house and engine to the alternator.

I am curious about your restoration charge procedure. I have the same battery bank as you, but I have yet to do a restoration charge on it. How did you discharge the bank? Were you planning to use your alternator alone to charge the bank back up? If so, do you have an upgraded alternator? According to the manual the ideal charging rate .4c, and the minimum is .2c, which means you need a minimum of 100a for 4x G31 Fireflys.

[sunrise4]

A couple of additional comments on my original post:

   All pos and neg battery switches were left ON while I discharged the house battery bank (running lights, fridge, etc.).

   The starter battery was fully charged (12.6 V) and healthy when the engine failed to start with the house batteries flat.

   I suspect the starting circuitry is wired wrong, somehow requiring power from the house battery to start the engine.

   The four house batteries appear to be ok, hopefully just needed a restoration charge to bring back the like-new performance.

In regards to the restoration charge:

The house battery bank consists of four Firefly G31 batteries, which I installed in Feb 2020.  I did a restoration charge Spring of 2022 for no particular reason except I wanted the batteries to be fresh for a planned 3 month trip away from shore power for most of the time.

This year we were underway for about 80 days with two nights at a dock were we were on shore power.  To get around we'd run the engine for 2-4 hours and to charge the batteries, most of the time reaching a 100% recharge.  I noticed that the voltage level started to go down more and more as the house batteries discharged over night.  Towards the end of our trip the battery voltage would drop to 11.8 or 11.9 V with the batteries discharged to 50%.  This was rather disappointing performance as I'd expect these batteries to hold at least a voltage of 12.2 V or higher at a 50% discharge.  I'm hoping that a restoration charge will bring these batteries back to a better voltage performance.

In regards to the restoration charge I was able to start the engine at a house battery voltage of about 10.5 V.  With the shore power battery charger ON (Sterling Pro Charge Ultra 50 A) and the alternator running (Balmar XT-170) the batteries were receiving a little over 180 A for about the first hour (a little over 0.4C).  The current then slowly started to ramp down and after about 2.5 hrs dropped to below 50 A.  At this point I stopped the engine and let the shore power battery charger finish off the recharge.

I have not yet confirmed that this restoration charge improved the performance of the house batteries but hope to do so over the next 1-2 weeks.

I hope this clarifies some things and answers some of the questions posed.

Any insight or solutions are much appreciated!

Thanks!

[Charlie-Bravo]

A bit of a challenge to remotely diagnose, but here are some thoughts ……

12.6V isn’t quite a fully charged engine start battery, it’s not bad, ( 13V + would be nice) but it should start the engine, so odd indeed that it doesn’t, a possibility is the engine battery isolator switch has failed , this could still allow the battery to charge, but possibly not be used to start the engine, but why the house bank allows engine start is very strange. The split charge relay which usually charges the engine battery first then switches over to the house bank could be burnt out, and effectively joining your house and engine battery but not very well, and batteries being of perhaps differing construction, reduce their voltage at a differing rate, …… but this doesn’t explain it all I know, but worth a look at the split charge relay.

On most ‘Jeanneau boats we find the mysterious isolator on the negative side of the battery circuit (along with the positive isolators) and no one seems to be able to explain fully why they exist, so, some folk re purpose this switch to join the house batteries positive to the engine battery, it’s quicker than digging out the jump leads to jump start the engine in the event of engine battery failure, you just throw the switch.  
The unknowing new owner hops on the boat, switches all the switches ‘on’ and all seems well, but with a joined house and engine bank you only find out something is not right when all battery power has gone, you may have had a ‘clever’ previous owner, who forgot to leave a note, or label the switch.
Examination of the cables on the back of the neg isolator just might be worth a look, even if it just rules it out of the equation.

Despite the ‘modern’ style of many newer boats wiring , the physics is still the same as it has always been, the cable trace to find the house link to the starter motor needs finding, and then deducing why someone thought it was a good idea.

Good luck tracing

CB

[Trevor]

Hello sunrise4,

That is certainly a bad problem to have. The whole idea of course of a start battery is so when you flatten the house battery you can still start the engine.

A lot of good advice has been given. The start battery wiring should be easy to trace from the battery, through the battery isolator and straight to the starter motor. It sounds like the start battery isn’t flat, just not being used to start the engine. Trace those cables and let us know what you find. An interesting problem indeed.

Trevor

[sunrise4]

I had some time to do more testing and trace the wiring.  The B20 engine panel in the cockpit is indeed powered by the house batteries as there is no power to the engine panel with the house battery cut-off switch in the OFF position.  I was able to locate the fuse and wiring that feeds the power to the engine panel in the cockpit, and found that it was directly wired to the house battery cut-off switch.  When I moved the feed wire over to the engine start battery cut-off switch I was able to start the engine with the house battery cut-off switch in the OFF position.  However there were some unexpected findings.

First, the wire from the battery cut-off switch is about a 6 AWG leading to a fuse holder with a 40A fuse (on my boat located in the compartment behind the battery cut-off switches and to the right on the wall with the engine compartment).  However the wire leading away from the fuse is at best a 10 AWG or even 12 AWG wire, which is clearly not enough for a 40A load.  Question, could someone check and confirm if their setup has a 40A fuse, or a smaller more appropriate fuse for the 10 or 12 AWG wire leading away from the fuse block?

Second, when I moved the feed wire from the house battery switch over to engine battery switch the starting sequence of the B20 engine panel behaved differently.  Strange, but I confirmed it several times including moving the feed wire back over to the house battery cut-off switch where it behaved normal again.  Normal to me has been 1) press the power button on the panel, 2) the panel beeps and the red warning icons light up red for a few seconds, 3) press the engine start button and the engine starts.  However when I moved the feed wire over to the engine battery cut-off switch the start sequence was 1) and 2) as above, but then when I pressed the engine start button the panel beeped again and the red warning icons light up again for a few seconds and almost simultaneously the engine started up.  Any comments on which sequence is 'normal' on your boat?

I will be back at the boat in another month and hope to investigate some more.

Thanks for all the feedback and suggestions!

Cheers!

[Charlie-Bravo]

Your start sequence, second version with the warning light and beep also occurring just after starting sounds correct, as it takes a few seconds for the oil pressure to build, and once oil pressure increases the ‘alarms’ go quiet. Your boat may differ from mine, but all boats I have been on behave this way. (perhaps I have been on a lot of dodgy boats)

The smaller cable may just power the engine panel, which in turn will power the starter solenoid relay … not actually powering the solenoid, there will be a chunky cable from engine battery to starter solenoid relay for that, your engine battery isolator switch would usually be on this chunky cable.
The 40A fuse with smaller cable sounds odd, I hope someone with an identical model can shed some light.

CB

[gary1277]

The 40A fuse with smaller cable is the same on my 2018 SO419. Power comes from the engine battery switch. Looks odd to me as well.

I have been chasing some electrical gremlins and have been tracing and remaking my grounding connections. I have found several poor connections which were surprising for a 5 year old boat.

Of particular note is the battery switches. The ground switch measured 60 Ohms across the terminals. After cycling it several times it measures less than 10mohms now. I was checking the forum today to see if anyone has reported similar problems.

Thanks for this discussion.

[sunrise4]

Gary1277,

Thanks for the info regarding your engine 40 A wiring, and sorry to hear about your grounding/connection issues.  I have not come across grounding or connection issues so far, but on your recommendation will exercise those battery switches periodically.

In regards to the 40 amp fuse and approx. 12 AWG wire leading from it, I did find a schematic in the Yanmar 4JH manual that shows a 50 amp fuse which may be in the same circuit location as we are finding on our boats.  It shows a 3.0 mm2 wire (size between AWG 12 and 14) to the fuse and a same sized wire leading away from the fuse to the starter relay.  My wiring is a bit different as there is a hefty cable from the battery cut-off switch to the input to the fuse and an approx 12 AWG wire leading away from the 40 amp fuse.  Not exactly the same, but indicates there must be some wire size de-rating justification maybe due to a transient load spike of the starter relay.  I'm not familiar with the ABYC standards for such a de-rating, but maybe someone here can comment?

On the question of start sequence, could you confirm that your engine starts up as follows:

1) press the power button on the panel, 2) the panel beeps and the red warning icons light up red for a few seconds, 3) press the engine start button and the panel beeps again and the red warning icons light up again for a few seconds and almost simultaneously the engine starts

Thanks!

23-10-26 Yanmar Starter Wiring.pdf (111.33 KB)

[allegria]

Hi Gary,

In relation to your question regarding the battery switches getting a very high resistance when turned on, yes, this is a common issue for these switches.
And yes, the get back to normal after switching them on and off a few times successively.

It has been reported before on this forum.
It is a good idea to activate them a few times every now and then to avoid this issue.

Cheers,
Allegria

[gary1277]

Sunrise,

Regarding the engine starting sequence; mine is as you described,
1) press the power button on the panel, 2) the panel beeps and the red warning icons light up red for a few seconds, 3) press the engine start button and the panel beeps again and the red warning icons light up again for a few seconds and almost simultaneously the engine starts.

Gary

[gary1277]

Sunrise,

I perhaps have a related issue. I've only owned this boat now for about 6 months, my fourth. I found that when I sit on the anchor overnight, then fire up the engine in the morning after a short time I frequently get an alarm at the DC panel for low voltage on the engine battery, <11.5V. After a short while, 15m, the engine battery voltage returns to normal. Further, after running for an extended time (5hrs), I get the low battery alarm again but the voltage recovers much slower, maybe 90m.

I have a few tests to do yet to verify this. I think what is happening is initially, on engine startup, the Cristic battery isolator is directing the alternator current to the house batteries (Firefly,464Ah) as the engine runs. The engine pulls the engine battery down (78Ah) at about 5 to 7 amps (?) when it sometimes gets to 11.5V and the alarm sounds on the DC panel. At this point, shortly before/after, the voltage isolator sees the engine battery is less than the domestic batteries and redirects alternator current to the engine battery. The Balmar 614 voltage regulator monitors the domestic batteries providing current based on the domestic batteries. After running sometime I suspect the battery isolator continues to charge the domestic batteries as demand is high and the engine battery runs down again.

The worst part of this is after a similar episode the engine shutdown because the ECM got fried. This is when I started to think it was all aggravated by a poor ground or connection. The engine was down for 6 weeks while Yanmar assessed, acquired, programed and shipped the replacement. Yanmar said they have never seen an ECM damaged this badly.

Sunrise, in your case I'm suspect the 40A circuit powers the ECM and the panel as I think the 50A circuit powers the starter solenoid and is located on the block next to the starter, but I have yet to check. If I'm correct, I think someone moved your ECM voltage supply to the regulated batteries to prevent something like what is happening to me.

The only info I've found on the Cristic battery isolator is their description on how it works, void of any numbers or useful specs.

I'm sure/hope I have some bad assumptions here. I plan on first checking all the power connections then try to duplicate the event at the dock when I can troubleshoot things real time. In the end likely replacing the battery isolator.

Any input will be greatly appreciated 👍

Gary

[Mistroma]

Oct 27, 2023 18:17:41 GMT gary1277 said:

Sunrise,

Regarding the engine starting sequence; mine is as you described,
1) press the power button on the panel, 2) the panel beeps and the red warning icons light up red for a few seconds, 3) press the engine start button and the panel beeps again and the red warning icons light up again for a few seconds and almost simultaneously the engine starts.

Gary

Yes, pretty well know problem. I was going to mention it earlier when someone mentioned the voltage drop between batteries and the meter in the saloon. I spotted that way back in 2012 when we were spending 6 months cruising. I have a Smartgauge beside the standard display and that connects directly to the battery posts. The voltage drop started around 0.1V and steadily increased to 0.4V during the summer. I found high resistance at the isolators and that rapid switching on/off several times cleaned the contacts.

I imagine weekend sailors don't have the problem as isolators will be off on Sunday and back on next Friday. I could leave the isolators on for 6 months at a time. I'd make a point of flipping the isolators once a month to minimise the voltage drop in the display.

[sunrise4]

Gary,

You describe an interesting but scary situation.  I'll have to further digest all the details in your post, but want to add one comment now.  When I installed the Balmar MC618 alternator controller and Balmar SG200 battery monitor I also changed the charging approach.  First, I wired the alternator output (with fusing) directly to the house batteries.  Then I installed a Victron DC-DC charger with its input wired to the house battery and its output wired to the input of the Cristec battery isolator.  For this to work I also had to remove the wire from the Cristec battery isolator output to the house battery, and to keep the battery isolator happy I double connected the engine battery on the Cristec battery isolator so that all outputs were connected to a battery (per the Cristec manual).

I have been running this way for about a year now without any issues.  I'm now thinking to add a second Victron DC-DC charger to have a dedicated DC-DC charger for each, the starter battery and the thruster battery.  This way I could completely eliminate the Cristec battery isolater. 

Maybe an approach like this could help with some of your issues?

[gary1277]

Sunrise,

Thank you for your insight on the DC to DC charger. I will check it out.

I verified on my engine the 50A fuse is on the engine just forward of the starter. It's connected to the starter pos terminal as shown in your diagram. The other end disappears in an umbilical bundle I assume to go off to the starter relay shown in the diagram.

The 40 amp fuse, supplied by the engine battery switch via 6AWG wire, goes to an umbilical under the ECU plugs. It rings out as the B60C/R5.0 wire in the diagram that powers the fuses on top of the engine.

Gary

[gary1277]

Oct 28, 2023 19:37:50 GMT gary1277 said:

Sunrise,

The 40 amp fuse, supplied by the engine battery switch via 6AWG wire, goes to an umbilical under the ECU plugs. It rings out as the B60C/R5.0 wire in the diagram that powers the fuses on top of the engine.

Gary

To be clear, on my boat the wire from the 40 amp fuse to the engine fuse box is the 10 or 12 AWG, same as Sunrise observed.

Gary