It seems my winter battery scheme has failed ?

Hoping I can tap into some of the battery/power wisdom already in this thread.

Trying to understand what may have caused battery(ies) on our C30 to drain such that the Garmin autopilots turned on and wanted the Dock and Sea trial wizards to run, the compass/GPS lost calibration so that boat was moving sideways on Garmin screen, and low voltage warning stayed on entire time with system voltage showing 12.4 at idle and dropping to 12.1 at cruise (boat cranks fine no issues. flipping parallel switch brings everything up to 14+). All 6 batteries were replaced at the of 2019 and boat is connected to shore power 24/7.

CO monitors have reached EOL and were beeping incessantly when I got to the boat tonight. Would that discharge the batteries faster than the charger can charge them back? Do I have a problem with drain on the thruster battery? Towards the end of last year, would always get low voltage warning but it would usually go away after cruising for a bit... replaced all 6 batteries proactively as we were approaching 5 years.

After reading up on it, I think I need to go back tomorrow to at minimum pull the fuses on the CO detectors... would appreciate any other thoughts or suggestions to understanding what may have happened!
 
(1) Is your boat using shore power with a battery charger charging the batteries. (2) When you leave the boat what battery switches are left on if any? What breakers are left on for equipment to run.(3) When you are running the engine what is the voltage readings of each battery bank?
Engine running, engine battery should be at or above 13V and increasing as you cruise. Once the engine battery voltage gets to 13V for 90 seconds the ACR's should close and parallel each battery bank as one. If either battery bank house or thruster is less than 9.5 V the ARC will not close and that battery bank will not charge from the engine. Using the cross over/parallel switch House to engine (on position) will "excite the battery" reset, and the relay will now close and the engine battery and house will be paralleled. Turn the cross over switch back to off when this happens. The thruster battery if it is below 9.5V will need a way to get a parallel circuit connecting house or engine battery "exciting the thruster battery". After you have done these steps you need to confirm that your ACR's are closed and all batteries are being charged. The ACR's green LED light should be on. If it is not you may have to troubleshoot the ACR's. Most common failure is the yellow ground lead is not attached properly to the correct ground terminal on the ACR.

What conditions were involved when the house battery discharged enough to cause the auto pilot to go into reset loosing its memory. Was the house battery left on without a charger? When the house battery is left on there are other circuits that are running the biggest culprit for amp draw is the refrigerator, inverter, auto pilot if on along with the chart plotter all are using available amp hr's. When not on board and house battery is left on the shore power battery charger should be on.

The CO detector draws very little. The battery charger 20 amp or higher should be able to maintain several 12V circuits being on and still maintain the batteries. I have left the boat without charging it for over a month without pulling any 24/7 fuses and never discharged a battery less then a couple of tenths of a volt. Although I do recommend removing the fuses if the boat in not in the water and in storage. I do not recommend removing them if it is in the water and may be used from time to time (including the CO detector fuse).

First check battery condition, battery terminal connections, load test each battery. Just because it is newer does't mean it's good. New batteries fail. Always start with the source (batteries) Troubleshooting. All Batteries fully charged and load tested (good)

Next check amperage draw at battery. All battery switches off check each battery draw should be around .5V to 1 V depending on what 24/7 circuits are used on the battery bank. (good)

ACR's, engine, thruster and house batteries at 12.75 V or more green light on, less than 12.75 green light off.

Engine running, engine battery at 13V, house and thrust are( good ) ACR's close green lights are on all battery voltages are the same. Green light not on trouble shoot ACR's

Shore power/generator. 120V charging. Charger on, charger output to each battery, when one battery reaches 13V and the other batteries are above 9.5 Volts ACRs close and all batteries should read the same, green light on. ( unless you have ACR's disabled when using Battery charger) If disabled you should still read all batteries above 12.7 Volts and climbing to between 14.3V to 14.7 V. if you are not getting readings this high when shore power is on and battery charger is on ,possibly a bad charger.

Troubleshooting: Start from the source and work out to find the issue.
 
Be sure to check that the ground wire on the ARC, a white wire on my boat. Mine came loose and it was hard to notice. Only by looking at the voltage on my plotter display did I see that it was not showing 14 while under way.
 
Hi Brian,

Thanks for taking the time to type out that response! I will try to respond inline to your questions.

I'm a bit of a novice at this electrical stuff so thanks in advance for your patience and appreciate any more insights before I end up calling a professional at $$$/hr to help figure this out!


BB marine":186dhx1h said:
(1) Is your boat using shore power with a battery charger charging the batteries. Yes, boat is connected to shore power with the ProMariner Charger as equipped from the factory (2) When you leave the boat what battery switches are left on if any? What breakers are left on for equipment to run. I was taught to leave just the House switch on and turn off the Engine/Thruster/Generator switches. I forgot to take a photo but I will next time I get to the boat for breakers left on... I think refrigerator is biggest power drain.(3) When you are running the engine what is the voltage readings of each battery bank? There are 3 battery banks. I think they were reading around 12.6-12.7 on the Blue Sea DC VOLTS panel (photo below when plugged in to shore power reading about 13.7). However, on the Engine display (and Garmin), it would alternate between 12.4 and 12.6 at idle and drop to 12.1-12.3 when at cruise/WOT.
Engine running, engine battery should be at or above 13V and increasing as you cruise. It drops below 12.6V and "LOW VOLTAGE WARNING" pops up on the Garmin and the Volvo display. It did that for a while prior to replacing all 6 batteries and I hadn't seen the Low Voltage Warning for a few outings since replacing all 6 batteries.


Once the engine battery voltage gets to 13V for 90 seconds the ACR's should close and parallel each battery bank as one. If either battery bank house or thruster is less than 9.5 V the ARC will not close and that battery bank will not charge from the engine. Using the cross over/parallel switch House to engine (on position) will "excite the battery" reset, and the relay will now close and the engine battery and house will be paralleled. Turn the cross over switch back to off when this happens. The thruster battery if it is below 9.5V will need a way to get a parallel circuit connecting house or engine battery "exciting the thruster battery". After you have done these steps you need to confirm that your ACR's are closed and all batteries are being charged. The ACR's green LED light should be on. If it is not you may have to troubleshoot the ACR's. Most common failure is the yellow ground lead is not attached properly to the correct ground terminal on the ACR. If I'm reading the above correctly, one or more of the batteries was below the 9.5V threshold and not charging? After reading the above, I went out on the boat and cruised around for a bit with parallel switch ON which seemed to raise the system voltage (shown on Volvo and Garmin screens) up a bit to 12.3-12.4 from the 12.1 I was seeing before. If I understand correctly, this should have raised whichever battery back above the 9.5V threshold evidenced by both ACRs showing GREEN after plugging back into shore power?

What conditions were involved when the house battery discharged enough to cause the auto pilot to go into reset loosing its memory. I'm wondering if someone who was working on the boat disconnected shore power for some reason over the past two weeks or perhaps we had a power outage? Would the house battery being low show up on the Volvo and Garmin screens as "Low system voltage"? Was the house battery left on without a charger? When the house battery is left on there are other circuits that are running the biggest culprit for amp draw is the refrigerator, inverter, auto pilot if on along with the chart plotter all are using available amp hr's. When not on board and house battery is left on the shore power battery charger should be on. House battery switch is always ON as boat lives in a slip connected to shore power except for when we are out for usually 2-4 hours at a time. It's possible the shore power was disconnected or maybe there was a power outage that allowed batteries to run down even though I thought it was all connected?

The CO detector draws very little. The battery charger 20 amp or higher should be able to maintain several 12V circuits being on and still maintain the batteries. I have left the boat without charging it for over a month without pulling any 24/7 fuses and never discharged a battery less then a couple of tenths of a volt. Although I do recommend removing the fuses if the boat in not in the water and in storage. I do not recommend removing them if it is in the water and may be used from time to time (including the CO detector fuse). I disconnected the fuses to stop the beeping while I wait for 10 year battery powered units to arrive. I'll be installing them unless I get feedback on the other thread that the units I bought shouldn't be used!

First check battery condition, battery terminal connections, load test each battery. Just because it is newer does't mean it's good. New batteries fail. Always start with the source (batteries) Troubleshooting. All Batteries fully charged and load tested (good) So, I'm a neophyte at this and don't know how to do that. I YouTubed and found this (https://www.youtube.com/watch?v=yp1LSWLKwuI). Can you recommend a load tester? Would I be able to load test the batteries on the boat without disconnecting or do I need to take each battery out to load test separately? The video talks about battery temperature... should I run the boat for a bit or do something to warm up batteries before load testing? Sorry for all the newbie questions!

Next check amperage draw at battery. All battery switches off check each battery draw should be around .5V to 1 V depending on what 24/7 circuits are used on the battery bank. (good) Same questions as above... Can I test this while everything is hooked up or do I need to disconnect each battery to test? As above, do you have a recommended tool for doing this? (I'll look up usage and testing procedures unless you can point me to some resources you know off the top of your head!)

ACR's, engine, thruster and house batteries at 12.75 V or more green light on, less than 12.75 green light off. So, if green lights were ON for both ACRs on shore power... good? I guess I'll find out next time I get to the boat whether all the batteries charged back up or if there's a problem with a battery and I still don't get system voltage over 13V while underway?

Engine running, engine battery at 13V, house and thrust are( good ) ACR's close green lights are on all battery voltages are the same. Green light not on trouble shoot ACR's I will check this next time... but if system voltage doesn't get up past 12.1-12.6 with engine running, then what?

Shore power/generator. 120V charging. Charger on, charger output to each battery, when one battery reaches 13V and the other batteries are above 9.5 Volts ACRs close and all batteries should read the same, green light on. ( unless you have ACR's disabled when using Battery charger) If disabled you should still read all batteries above 12.7 Volts and climbing to between 14.3V to 14.7 V. if you are not getting readings this high when shore power is on and battery charger is on ,possibly a bad charger. So ACRs were both GREEN and batteries on the BLUE SEA panel were showing about 13.7V so good?

Troubleshooting: Start from the source and work out to find the issue.

Thanks again for the above and hopefully your responses can help other novices like myself who don't quite understand all this electrical jargon!


So, took some photos of all the various components that I referenced above.

This is the Volvo display which shows "system voltage" of 13.6 (and went up to 13.7) after shore power was connected. Same number shows up on the Garmin. I never understood what this number represents. Is it the starter battery? The house batteries? The thruster battery? A combination of the aforementioned?:
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This is the ProMariner TruePowerCombi2500QS. It's set to position 2 (AGM1 - posted question in other thread about whether this should be AGM1 or AGM2). It shows "Charging" (yellow light blinks) and on "Shore Power"
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This is the upper ACR (mounted in the battery switch compartment in the cockpit - never even knew this was in here until I researched ACRs and tried to figure out where they were on the boat!) which is showing GREEN after shorepower was reconnected:
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This is the lower ACR (mounted in the battery switch compartment in the cockpit. It's mounted behind a ton of cables. Not sure how to get to the rest of it or if I need to! I think I need to check the ground on both of these right?) which is showing GREEN after shorepower was reconnected:
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This is the BLUE SEA DC VOLTS panel which shows voltage for 3 battery banks. I don't know which each represents. It's confusing to me as there are 6 total batteries (4 on port side, 2 on starboard) separated into 3 groups (4 house, 1 starter, 1 thruster) but there are 4 battery switches (HOUSE, ENGINE, THRUSTER, GENERATOR)?
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I'd hoped that swapping out all 6 batteries at the end of last year would have solved the constant nagging "LOW SYSTEM VOLTAGE" warnings that became more and more frequent (but would typical go away after cruising for a bit). I had always just assumed that the starter battery was getting old and so would lose voltage after starting the engine... but now I'm not so sure anymore!
 
Pilotnavigator":2x5ph64d said:
Be sure to check that the ground wire on the ARC, a white wire on my boat. Mine came loose and it was hard to notice. Only by looking at the voltage on my plotter display did I see that it was not showing 14 while under way.

What voltage showed up on your plotter when the ground wire was loose? My voltage while underway was nowhere near 14 and hovered between 12.1-12.3 when cruising or 12.4-12.6 while idle...

Would the ACRs show green when the engine is off and charger plugged into shore power if the ground wire was loose? I'll have to look at it next time I'm back at the boat!
 
I would say you are not getting alternator charging to you house batteries. When my ground wire was disconnected I got 12.8 volts shown at the plotter display. When the ground wire was reconnected I was back up to 14.1 I a few minutes. I can watch the voltage come back up after a long time at anchor with solar only. The plotter will show the house voltage at around 12.5 then I start the engine and it will jump to around 13.5 and slowly rise and top out at 14.1.
From your picture I can’t see the white ground wire coming out the bottoms of the ARC. Flip the two tabs on the side and remover the cover to get a better look at the connections on the bottom of the unit. There should be at least two small connections one is ground and should go directly to your negative post on the house battery.
Take the cover off and send a picture.
John
 
Once the alternator kicks in all voltages should go up to 14. If not something is wrong. Once all the connections are checked. Test each line with a clamp meter to verify current is going into each battery bank. Clamp the alternator wire first to see that it is putting out current, mine is a 120 amp so at high idle it should make around 40 amps. Then check both sides of the ARC and you should see the same current or close to it. Assume all loads are off. Voltage at starter battery should be 14 and also the house batteries. At least they should once the ARC closes. If house is low them wait and see if the ARC closes in a few minutes. You can put a jumper cable across the two red lines of the ARC and simulate a closed connection. Voltage should then be the same everywhere. As this is what the alternator puts out.
 
asm777":2df1g0d1 said:
'd hoped that swapping out all 6 batteries at the end of last year would have solved the constant nagging "LOW SYSTEM VOLTAGE" warnings that became more and more frequent (but would typical go away after cruising for a bit). I had always just assumed that the starter battery was getting old and so would lose voltage after starting the engine... but now I'm not so sure anymore!

The troubleshooting starts at the batteries. Are the batteries getting charged from each charging source? Here is a easy way to check and understand the charging systems. Use a simple VOA meter analog or digital setting DC 20V. Engine not running shore power charger breaker off. ( No charging source ) confirmation of ACR green light on or off. This testing you want it to be off and it should be unless you find the battery voltage above 12.75. Use the VOA meter red lead to + terminal, black lead to - terminal of each battery. Record each battery or battery bank voltage. The engine single battery, thruster single battery, house multiple batteries. Readings with good batteries fully charged should be between 12.5V and 12.7V. If voltage readings are lower then this, batteries need to be fully charged or you have a bad battery in the bank.

Turn battery charger on, wait 15 minutes minutes for the charger to begin to charge. Repeat the same testing and record results. The voltages should be higher at each bank than previous recorded voltages if charger is charging properly. If you see a Voltage of 13.0 V or more look at the ACR's and see if the light is green ( green light should be on) This test is proving two things, the charger is working and ACR's are working. If voltages did not increase the charger is not working. If the ACR's are not lit and the voltage of one battery bank is higher than 13.0 V the ACR's are not working.

Turn all breakers 30 amp panel to off position and remove shore power plug. Start engine let it warm up for a few minutes. advance the throttle (neutral) to 1000 rpm. Repeat the same testing. Engine battery should show higher then first test recorded voltage. Engine battery voltage should be 13.0V or higher. If the battery voltage does not reach 13V or show an increase in voltage after a few minutes of running the alternator is not working properly. If it does show an increase in voltage look at ACR's, is green light lit? (yes) all battery voltages should read the same. ACR's are not lit (+13V) ACR's are not functioning properly.

If after testing with the VOA tester all battery Voltages seem to be in range the charging systems are functioning properly. If you are still having an issue with low voltage when boarding the boat after a few days and the boat was plugged in and charger on. I would suspect shore power loss at the dock. If you have a low voltage issue while cruising and at anchor( no shore power) power management of 12volt systems may be needed or one of the batteries has a bad cell and is discharging the bank ( easy test for this is fully charge all batteries) disconnect the ground leads from the batteries check voltages of each battery. Record voltages, Wait a few hours, retest batteries, voltages should be very close to the same readings. If you have a battery that has a lost 50 to 75% of its charge in a few hours it is bad. 12.4 to 12.0V

These steps test the charging system and battery condition. This needs to be confirmed first before assuming there is an issue with the boats electrical system. If you have a known good charging system and known good batteries. Troubleshooting a ghost amp draw can be made easier when the source (charging-batteries) are known to be good. Good luck in your troubleshooting the system. If you have other questions PM and I can add suggestions to try to help.
 
John/Brian,

Thanks to both of you for taking the time to help out and share your insights!

I think I've narrowed it down to an issue with the alternator not charging while underway (which has been going on for a while, I just never realized it).

I checked the ACRs and all the battery connections and didn't note anything loose or disconnected. I actually unplugged and replugged in both ground wires into their respective ACRs and it doesn't seem to have changed anything.

The ACRs appear to be working as they're supposed to. It's just that the alternator is for some reason not charging the batteries while underway.

I haven't had a chance to actually check each battery yet and will try to use the procedure Brian spelled out for me to check them, but from checking on the boat a few times over the past few days, I think the charging system via shorepower is working fine. The ACRs are working correctly, and all 3 battery banks get above 13V after letting the charger do it's thing. The battery banks will get up to 14v when connected to shore power when charging is happening and when I get back to the boat, the charger shows "READY" instead of charging and all the banks over 13V as mentioned before.

After unplugging shore power and starting up the engine, the voltage now seems to fluctuate between 12.4-12.8 and doesn't get up over 13-14 as both of you mentioned. After turning the engine off, voltage returns to about 12.7-12.8 and seems to stays there (I did note it ticked up to 12.8-12.9 while I was working on other things - I think from solar system charging?)

Anyway, if either of you have insights into how the alternator might be wired into the battery system (I have a question out to the factory as I didn't see it in the manual), maybe I'll be able to troubleshoot some more and figure this out myself.

But I'm getting the feeling this may be above my paygrade so I have a call out to our local Volvo techs and on their calendar for March 20th (yeesh, they're always so busy!) so I do have over a month to try to figure it out myself before the pros come to rescue me! :lol:
 
Sounds like you do not have a clamp meter for dc systems. Get one or borrow and clamp not the big fat alternator wire and read the dc current on the line when the engine is running. You may end hear or feel the engine tone change when the alternator kicks in after a few seconds after engine start. If the current reads low the alternator is bad. You may be able to suspect it if the engine does not drop rpms when the alternator should kick in and start making current.
A reasonably priced clamp meter for dc current is around 100 bucks. A very good one is 200. Cheaper ac clamp meters go for a lot less but will not perform as well on dc currents. My opinion is one is essential in diagnosing boat electrical issues. Save your money on the fancy inline voltage current monitors and get a good diagnostic tool.
 
Pilotnavigator":u6zxpzpq said:
Sounds like you do not have a clamp meter for dc systems. Get one or borrow and clamp not the big fat alternator wire and read the dc current on the line when the engine is running. You may end hear or feel the engine tone change when the alternator kicks in after a few seconds after engine start. If the current reads low the alternator is bad. You may be able to suspect it if the engine does not drop rpms when the alternator should kick in and start making current.
A reasonably priced clamp meter for dc current is around 100 bucks. A very good one is 200. Cheaper ac clamp meters go for a lot less but will not perform as well on dc currents. My opinion is one is essential in diagnosing boat electrical issues. Save your money on the fancy inline voltage current monitors and get a good diagnostic tool.

So I spent some time trying to read up on alternators and clamp meters and also went and reviewed old notes. It looks like we've been having Low System Voltage warnings for the past few years and I just wasn't knowledgeable about how the boat electrical system is supposed to work to notice that we've had a problem all this time. Just thought it was a sign that batteries were getting older...

Anyway, went and poked around the alternator and took some photos. From what I could see, the belt tension seemed fine so I'm thinking either the alternator itself is bad or I need to track down a loose connection?

When you say the big fat alternator wire, is that the red one in the photos below? It's so tight in there that I couldn't get the clamp meter around it.

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I'm hoping to be able to make a determination on whether the alternator is bad or if there's a loose connection somewhere before the Volvo tech comes out next month. If the alternator is bad, I'd want them to order bring out a replacement so that it doesn't take two trips to repair/replace!

I've reached out to the factory to see if they can guide me in troubleshooting this as the wiring diagrams in the C30 manual don't show the alternator but if anyone has any other thoughts/feedback, would appreciate it!

Learning a lot so thanks for your patience and sharing your knowledge as I try to figure this out!
 
Just trace the alternator red wire back to the battery and you should find a place to access it around the ARC device. On my 21ec the alternator charges on the same cable as used by the starter. Get the engine going at fast idle and you should read a high current at the ARC on the starter side. Once the ARC combines the same current should be seen on both sides of the ARC. Even if you have devices on the clamp meter should show around 40 amps and higher as the rpms go up. Your connections at the alternator look good. So if the current is low have the alternator serviced by a tech. It is the same as used by cars and trucks so a good auto shop should be able to test and service it.
 
For simple accurate testing I would recommend the steps I outlined in a previous post.

Turn all breakers 30 amp panel to off position and remove shore power plug. Start engine let it warm up for a few minutes. advance the throttle (neutral) to 1000 rpm. Repeat the same testing. Engine battery should show higher then first test recorded voltage. Engine battery voltage should be 13.0V or higher. If the battery voltage does not reach 13V or show an increase in voltage after a few minutes of running the alternator is not working properly. If it does show an increase in voltage look at ACR's, is green light lit? (yes) all battery voltages should read the same. ACR's are not lit (+13V) ACR's are not functioning properly.

Testing an alternator for amperage output is a way of testing the alternators ability to be capable of maximum output. It is an accurate test to see what condition the alternator is in. This is the testing that a rebuild shop does to determine the health of the alternator. To accurately test the alternator this way a measured load is applied to the alternator circuit and the alternator is tested to see if it is cable of matching or exceeding the load. If your alternator has a Max out put of 180 amps it doesn't always have that output unless it is required based on load. If you keep things simple basic trouble shooting an alternator is done by just checking the voltage at the battery. Good battery 12.5 to 12.7V resting no charger no alternator output checked with your volt meter set at 20V. Now start the engine. let it warm up for a few minutes. Increase the Rpm to help excite the alternator 1000 rpm to 1200 rpm is normally enough. You should see an increase in voltage at the battery red lead on + black lead on -. The voltage increase should be gradual as the alternator amp output charges the battery. Depending on the condition of the batteries and the load on the circuit ( engine and house circuits) the alternator amp output will change to maintain the batteries at or above 12.7 to 14.7V with the engine running. The known factor is you want the voltage reading to be above 13V with the engine running and no higher than 14.7. I'm not disputing that testing an alternator with an amp meter is not a good way to test. It is a bit more complicated because there are more factors that go into it. Voltmeter testing is known static voltage, and charging voltage. Engine running , increased voltage above 13V to no higher than 14.7 "normally" an alternator is considered good and continued trouble shooting of the boats 12V systems is required. If the Voltage increase seems marginal and you want confirmation that the alternators output meets manufactures specification I would remove the alternator take it to a electrical rebuild shop have them do a load output test (amp test) to confirm the alternators condition. Keep it simple but use a known good volt meter do not rely on the volt meters on the boat. They are in the boats 12Volt circuit and can be misinterpreted sometimes. My opinion based on many years of troubleshooting 12 volt and 24 volt marine charging systems.
 
Just a quick update and thank you to all who helped in this thread.

Volvo tech confirmed that alternator failed and replaced today. Boat is now happy and system voltage showing ~14 with engine running.

Yay! Hope everyone is staying safe amidst the COVID-19 madness.
 
Just when I'm ready to go in the water. The Gov shuts us all down. No recreational boating in Maryland, 'till 4/30.
I've got my new batteries installed and only have 2-3 wires to connect.
Well, no hurry now.
Except I want to get the solar panel back up and running during the shut-down.
Stay safe everyone.
 
The Gov shuts us all down. No recreational boating in Maryland, 'till 4/30.

Yeah, but you can fish. So get a cheap rod and you are good to go. 🙂

If you can gas up
 
This site is amazing for how to on boat maintenance and issues. Great articles on battery degradation over winter. Battery and charging system studies, This was the go to site for my first boat. Well worth the look.

https://marinehowto.com/
If you have a spare minute take a look very informative.
Glenn
 
yes its the solenoid that draws a bunch. you may also have a bilge pump on the battery.
 
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