Current troubles?

[Andyaero]

I liveaboard, haven't moved since the end of March when all appeared fine. Went to move yesterday, "click" nothing, as if the battery was dead. But do these readings show that its not flat, but has no current?

The chargers are off due to "engine shutdown detected" so I disabled the shutdown system, but still nothing. Its an 18 month old lead acid starter, with 600ah lithiums.

Wouldnt start with a jump pack either. Any ideas?

 

 

Edited May 2 by Andyaero

[Jen-in-Wellies]

The click does suggest the starter batt can't supoort a starter motor current drain. Look for poor connections between the batt and starter motor, including any isolator switch. Also including ground connecrions from batt to engine. If these are OK, could be a dead starter batt. The fact that disabling engine start detection on the B2Bs didn't flow any current suggests one of these two things. Pulling 100A from a dead batt, or through a poor connection is going to be as likely as being able to start. 

[Andyaero]

 

When I disable the engine start detection, current shows, but I still get no more than a click.

 

[Alan de Enfield]

4 minutes ago, Andyaero said:

When I disable the engine start detection, current shows, but I still get no more than a click.

 

The current used to turn over the engine will be (normally)  between 150 amps and 300 amps- depending on starter model

 

If your battery is only 'outputting' 4.1 amps you have a problem somewhere.

[blackrose]

As Jen suggests, check connections. Start with the battery connections.

[Tony Brooks]

I see nothing to indicate if those readings are for the domestic or start battery bank. 

 

What is the open circuit voltage and cranking voltage measured at the start battery terminals.

[nicknorman]

If it is a single click and not chattering, I think it is likely that the starter solenoid is defective. Maybe it got a bit corroded with lack of use? Or maybe ditto for the thick cable from the starter battery to the starter, and its connections. The starter battery, at 12.89v, looks well charged.

As a first step I would hit the starter motor with a calibrated hammer to wake it up. If that fails, try shouting at it and beating it with a tree branch (channel your inner Basil Fawlty).

[Andyaero]

Will check tomorrow when I'm back at the boat in the light. Is the starter battery reading on the BMV of 12.89 the open circuit voltage? All connections felt fine and nothing improved when gently wiggled, which puts me at about the limit of my electrical competence.

[Tony Brooks]

Unless you have the "ignition" on or are trying to start it then that 12.89V is the open circuit voltage BUT that is too high for a fully charged, rested lead acid battery. I would expect a start battery showing 12.8V to start the engine easily.

 

What make and model of engine? I would not hit the starter with any sort of hammer if there is any possibility of it having permeant magnet fields. They can shatter, but those starters are usually geared. Use mallet, rubber hammer, or the heel of a stout shoe or boot.

 

It certainly could be dirty solenoid contact, as Nick says, but the cranking voltage at the battery should show that as very little difference between that and the open circuit voltage.

[wakey_wake]

3 hours ago, Andyaero said:

Went to move yesterday, "click" nothing, as if the battery was dead.

 

I believe we are all assuming this "click" is from the starter solenoid.

 

My BMC system has several small relays behind the ignition panel, some of which are fed from the domestic supply (and maybe shouldn't be?).

 

It leads me to wonder whether this is a small "click" of a small relay, rather than a heavy "clunk" of the starter solenoid.

@Andyaero can your ears discern a direction so you know which part is clicking?

 

Depending on wiring, it's also possible the engine isolator is off 🤦‍♂️ but the starter remains visible to the Victronics.

[Quattrodave]

Can you turn the engine by hand? Ok no literally by hand but bar it over a good half revolution just to check it can actually turn... If it turns ok, connect the jumper pack straight accross the starter motor.

[MtB]

15 hours ago, Andyaero said:

Will check tomorrow when I'm back at the boat in the light. Is the starter battery reading on the BMV of 12.89 the open circuit voltage? All connections felt fine and nothing improved when gently wiggled, which puts me at about the limit of my electrical competence.

 

Now would be a BRILLIANT time to get yourself a DMM, and use it (with some guidance from the board if necessary) to trace this fault. It is quite likely to be a poor connection and measuring some voltages in the supply to the starter will find it. Can be a very rewarding thing to achieve for the first time! 

 

It will probably be quite easy, provided you have four hands. Or can borrow a pair.

[Tony Brooks]

14 hours ago, wakey_wake said:

 

I believe we are all assuming this "click" is from the starter solenoid.

 

My BMC system has several small relays behind the ignition panel, some of which are fed from the domestic supply (and maybe shouldn't be?).

 

It leads me to wonder whether this is a small "click" of a small relay, rather than a heavy "clunk" of the starter solenoid.

@Andyaero can your ears discern a direction so you know which part is clicking?

 

Depending on wiring, it's also possible the engine isolator is off 🤦‍♂️ but the starter remains visible to the Victronics.

 

There is always the possibility that the click is from a relay or old car type starter solenoid close to the starter motor, but the OP has to look for it and find out how his system is wired, although this is less usual on narrowboats where the starter and start/ignition switch are more usually within a meter or so of each other. I am awaiting the two voltage readings I asked for before commenting much further, but there are other less common possibilities like worn starter brushes, resistance in the ignition/start switch and wiring to the starter.

 

I am still can't see any reading that specifically refers to the start battery, I suspect they are all for the domestic bank.

 

The OP needs to distinguish between the clunk of the starter solenoid pulling in and the light click or a relay.

 

 

 

 

[Gybe Ho]

17 hours ago, Andyaero said:

When I disable the engine start detection, current shows, but I still get no more than a click.

 

 

That is because the DC/DC is valiantly trying to charge the big lithium battery with whatever charge there is in the starter battery even though the engine is not running hence there is no alternator charge present. 4 amps is all it could manage because presumably it was competing against the MPPT that was driving 29 amps into the lithium battery at the same time.

 

Net-Net is you have depleted the starter battery a bit. Even so the initial starter battery voltage of 12.64 (resting) indicates a decent state of charge after 2 months of engine inactivity. Right now it would be best to follow a classic pre lithium and pre Victron wizardry diagnostic path for your starter woes.

 

Are the two DC/DC's wired in parallel because your engine has a big alternator?

[Gybe Ho]

3 minutes ago, Tony Brooks said:

 

I am still can't see any reading that specifically refers to the start battery, I suspect they are all for the domestic bank.

 

 

The reading you seek is the input voltage on the DC/DC's.

[Tony Brooks]

15 hours ago, wakey_wake said:

My BMC system has several small relays behind the ignition panel, some of which are fed from the domestic supply (and maybe shouldn't be?).

 

Now why does that not surprise me.

 

If you have twin alternators then the proper way to wire the domestic alternator warning lamp circuit is to use a relay activated by the start battery & ignition switch to connect the domestic battery to its charge warning lamp. That is normal, but I can't think of any other valid reason for a BMC to have more relays under the ignition panel, especially any connected to the domestic bank. I can think of a few reasons that may be better addressed in a less complicated way.

 

If the engine is a long way from the ignition panel than it may be sensible to use relays situated close to the engine to energise the starter solenoid and glow plugs, but they would both be totally powered by the engine battery.

 

A can envisage a boater who is worried that his fridge or similar high current device would discharge his domestic batteries so they MIGHT decide to use a  relay that only powered that circuit when the ignition was on and by extension, when the engine is running to provide charge. 

 

If one s rather larger than a typical 12V relay then it could be a split charge relay, but in my view it is a silly place to locate it because putting it there involves longer charging cables. In that case one large cable would be connected to the engine battery and the other to the start battery. 

56 minutes ago, Gybe Ho said:

 

The reading you seek is the input voltage on the DC/DC's.

 

Which in my view should be high enough to allow the engine to start battery, but I still can't see the start battery cranking voltage. If that remains above about 10V (or by experience a little less) then we have a circuit fault between battery and main starter connection. If t falls below that then the battery or the terminals must be suspect.

[Andyaero]

Thanks all, all great advice, just to keep updated, family has called, so this is gonna be a tomorrow job, don't want you thinking I'm ignoring the advice!

The starter battery reading on the BMV is showing 13v now, so does this mean it is trickle charged by my solar, a set up I've seen mentioned somewhere.

Cheers

 

 

1 hour ago, Tony Brooks said:

 

The OP needs to distinguish between the clunk of the starter solenoid pulling in and the light click or a relay.

 

 

 

 

Definitely a very short clunk, from within the engine bay

[MarineHeatingSolutions]

You've had some great advice regarding connections, but if those all check out, there are two specific areas you should look at next:

• The 'Voltage vs. Load' Test: You mentioned the BMV shows 13V. This might just be a surface charge (likely from a solar trickle-charge circuit if your BMV is wired to monitor the starter). The real test is what that voltage does when you turn the key. If it drops from 13V down to 11V or lower during the 'click,' the battery is likely knackered, regardless of it being only 18 months old. Lead-acid batteries can fail early if they've sat partially discharged.

• The Starter Solenoid: Since you can hear a 'click,' the solenoid is trying to do its job, but the internal contacts might not pass the high current needed to spin the motor. If you can safely access the connections of the starter motor, you can try to bypass the solenoid by briefly bridging the main high-tension terminals with a heavy-duty insulated tool (watch for sparks!). If the motor turns, then you know the solenoid is your culprit.

• The 'Tap' Method: It’s an old-school trick, but sometimes the starter brushes get stuck. Give the body of the starter motor a firm (but not destructive) tap with a hammer or a heavy spanner while someone else holds the key in the start position. If it suddenly fires up, your starter motor is on its way out.

The fact that it wouldn't start with a jump pack is the most telling sign—it really points toward either a failed starter motor/solenoid or a major break in the cabling/grounding between the battery and the engine block."

[Gybe Ho]

2 hours ago, Andyaero said:

 

The starter battery reading on the BMV is showing 13v now, so does this mean it is trickle charged by my solar, a set up I've seen mentioned somewhere.

 

 

As you have 2 DC/DC units they might be flipped to allow one to feed solar power to your starter battery but that is an exotic configuration, also the voltages shown in your first screen shot were not consistent with one reversed DC/DC having an input voltage that matches the elevated voltage from the MPPT charging at 29 amps.

 

More likely the previous owner of your boat wanted to take full advantage of a high power alternator.

 

Could the 13v on the BMV be misleading. Since your boat has had a substantial electrics upgrade the "starter  battery" voltage might be showing something else? If it is the genuine starter voltage you could answer @Tony Brooks's question about whether the voltage crashes when the starter is engaged. 

 

A fulltime boater needs a multi meter, the LAP AC/DC True RMS Digital Multimeter 600V available from Screwfix has a nice big display and no confusing rotary scale dial switch.

[wakey_wake]

4 hours ago, Tony Brooks said:

20 hours ago, wakey_wake said:

My BMC system has several small relays behind the ignition panel, some of which are fed from the domestic supply (and maybe shouldn't be?).

 

Now why does that not surprise me.

I've yet to take that panel off and investigate properly. The engine runs so I'll let that sleeping dog lie a while longer.

However a peek through the cupboard to around the back of it suggests several parts are vestigial.

 

It doesn't have is a glowplug relay, so seems to be running 50A up some not especially thick wire, through the ignition switch, and back down. It's not far but I'm surprised it works.

 

The mariniser's wire bundle has clearly been untouched for a long time. It is wrapped in PVC tape or similar, which has spatters of sprayfoam on it 🤯 suggesting an odd history. The engine bay is sprayfoamed up the hull sides from uxter plate to cabin top, forward of the fuel tank.

 

4 hours ago, Tony Brooks said:

If you have twin alternators then the proper way to wire the domestic alternator warning lamp circuit is to use a relay activated by the start battery & ignition switch to connect the domestic battery to its charge warning lamp.

The second alternator is 24V for the bowthruster, but it looks like that never recharged properly. Motor was gone and the batteries summed to 6V.

I think it has no warning lamp? I only recall the two heavy connections.

 

4 hours ago, Tony Brooks said:

That is normal, but I can't think of any other valid reason for a BMC to have more relays under the ignition panel, especially any connected to the domestic bank. I can think of a few reasons that may be better addressed in a less complicated way.

 

If the engine is a long way from the ignition panel than it may be sensible to use relays situated close to the engine to energise the starter solenoid and glow plugs, but they would both be totally powered by the engine battery.

 

I know mine has relays for the nav light and horn, which are from the domestic bank. The purpose of the others will come out eventually.

 

The reason I mentioned them at all is that we should be careful about the meaning of "a click", until it's more qualified.

 

 

 

3 hours ago, Andyaero said:

The starter battery reading on the BMV is showing 13v now,

 

I believe many of us had doubts about what those readings actually represent, partly because the readings didn't seem to match up with each other, so until you have built some confidence in which voltages shown on the phone relate to what actual batteries then it could be misleading to infer a cause such as

 

3 hours ago, Andyaero said:

so does this mean it is trickle charged by my solar, a set up I've seen mentioned somewhere.

 

As Tony and MHS said, putting a load on the starter will give information. If you have glow plugs on an ignition key position, they're a good way to put a load on the battery. Maybe an Orion will show you a graph with a dip in it, that corresponds to the time you engage glowplugs?

 

 

 

1 hour ago, Gybe Ho said:

A fulltime boater needs a multi meter, the LAP AC/DC True RMS Digital Multimeter 600V available from Screwfix has a nice big display and no confusing rotary scale dial switch.

 

A nice find from a place I would trust not to sell junk. 👍

However my choice for a boater would be the cheaper https://www.screwfix.com/p/lap-dc-digital-multimeter-600v/793rt (with dial). I don't find dials confusing, but options hidden behind one button and presumably a lot of logos around the edge of the screen? Uncharted territory for me.

 

The most important thing about a multimeter is you can see what you're measuring, and if necessary take photos of it. The Victronics certainly measure stuff and can give you numbers from a distance, but you have to know what they're looking at, and maybe also have an idea what currents are flowing in the wires they used to sense voltage.

[Gybe Ho]

1 minute ago, wakey_wake said:

 

A nice find from a place I would trust not to sell junk. 👍

However my choice for a boater would be the cheaper https://www.screwfix.com/p/lap-dc-digital-multimeter-600v/793rt (with dial). I don't find dials confusing, but options hidden behind one button and presumably a lot of logos around the edge of the screen? Uncharted territory for me.

 

No it boots up into "Scan" mode then just touch the battery terminals with the probes and it thinks for a second before deciding what you are measuring. Two more clicks and the screen icon indicates a graphic for DC volts if you want to manually set the mode. Best thing is the space saved by removing the manual dial switch means a bigger colour LCD display. 

[Ronaldo47]

On a canal holiday more than  30 years ago, we had much the same symptoms (a click, but no starting) on the morning we were due to return our boat. No mobile phones then, and I thought I might end up having to bow haul the mile back to the boatyard, but following some fairly gentle tapping on the starter solenoid, it decided to work. 

[MtB]

8 hours ago, MarineHeatingSolutions said:

You've had some great advice regarding connections, but if those all check out, there are two specific areas you should look at next:

• The 'Voltage vs. Load' Test: You mentioned the BMV shows 13V. This might just be a surface charge (likely from a solar trickle-charge circuit if your BMV is wired to monitor the starter). The real test is what that voltage does when you turn the key. If it drops from 13V down to 11V or lower during the 'click,' the battery is likely knackered, regardless of it being only 18 months old. Lead-acid batteries can fail early if they've sat partially discharged.

• The Starter Solenoid: Since you can hear a 'click,' the solenoid is trying to do its job, but the internal contacts might not pass the high current needed to spin the motor. If you can safely access the connections of the starter motor, you can try to bypass the solenoid by briefly bridging the main high-tension terminals with a heavy-duty insulated tool (watch for sparks!). If the motor turns, then you know the solenoid is your culprit.

• The 'Tap' Method: It’s an old-school trick, but sometimes the starter brushes get stuck. Give the body of the starter motor a firm (but not destructive) tap with a hammer or a heavy spanner while someone else holds the key in the start position. If it suddenly fires up, your starter motor is on its way out.

The fact that it wouldn't start with a jump pack is the most telling sign—it really points toward either a failed starter motor/solenoid or a major break in the cabling/grounding between the battery and the engine block."

 

Isn't cut and pasted AI content banned on here?

 

 

[Tony Brooks]

55 minutes ago, MtB said:

 

Isn't cut and pasted AI content banned on here?

 

 

 

and AI seems to not know that with modern permanent magnet field starters giving the starter a "firm" tap can shatter the field magnets, One persons "firm" is another persons heavy clout. I am surprised MHS did not know that (considering his qualification list) and did not censor that part.

[nicknorman]

13 minutes ago, Tony Brooks said:

 

and AI seems to not know that with modern permanent magnet field starters giving the starter a "firm" tap can shatter the field magnets, One persons "firm" is another persons heavy clout. I am surprised MHS did not know that (considering his qualification list) and did not censor that part.

Do modern starters tend to be permanent magnet field? Genuine question because I would have thought an electromagnet field starter would be lighter and cheaper. But quite possibly I’m wrong!