Batteries not consistently charging

[Hydraulicjump]

I checked in with Andrew on this and it is an uncommon problem, so I thought I would toss it to the rest of you for ideas on where to start.

As background, I have brand new flooded batteries (replaced my AGM's, set up my ProMariner charger/inverter for flooded, put all connections back as original). Only real electronic mods are a Blue Seas battery switch that allows me to parallel my house and thruster batteries (which I leave in parallel all the time), and a Balmar Smartgauge which just monitors battery voltage/capacity. I have the standard Morningstar solar panel and no generator.

When hooked up to shore power all works fine, with all batteries taking and holding a charge per ProMariner specs.

When overnight on the hook, however, I get an unusual charging--or lack thereof--cycle when motoring the next day. Upon start-up, the engine battery gets 13.3v for a brief period (ten minutes), and then drops to 12.8 v and is held there. Occasionally, it will pop up to 13+v briefly and then drop back to 12.7-8 v. The house batteries on the other hand, will sometimes come up to 12.7-8, but on occasion will just stay at the 12.4 v that they were drawn down to the night before. After several hours of engine runtime this won't change (for example, Sucia Island to Bellingham at various rpms). No discharge, but no charge either. Interestingly, my Balmar Smartgauge confirms that there is no net gain or loss in house battery capacity during this.

And here's the catch: this is not consistent. Sometimes things are just fine and both banks charge up equally. But occasionally, this weirdness I just described happens. I have found that turning off the engine and restarting it can get the charging on the engine battery back into the 13+ range for a while, but it doesn't solve the battery bank charging problem.

So where to start? Three potential culprits I guess: alternator is tired and not delivering reliable juice, voltage regulator is not doing an adequate job, or ACR's are acting goofy. Good news is that as long as I hit a marina now and then with power or I have a nice sunny day, things are OK. But it would be nice to figure this one out.

Thanks for suggestions. I will be back at the boat (left it in Bellingham before flying back to California yesterday) on the 23rd with a clamp on multi-meter in hand, and then taking it to the Rendezvous. Hopefully some of you electrical wizards will be there to help diagnose this evil spirit.

Jeff

 

[SGIDAVE]

Hello Jeff,

You have narrowed it down the the three items I would have thought. It would seem your alternator or it's voltage regulator are more likely of the three listed. I say this since the engine battery (verify that your alternator charge wire is connected to the START battery - it sounds like it is) itself does not receive appropriate charge voltage upon start up. Initial charge voltage should be more like 14 VDC. So there is an issue there for sure. On the other hand, maybe your engine "bank" (1 battery, I presume) may become sufficiently charged after 10 minutes that the alternators voltage drops. In that case the ACR is malfunctioning. I believe you can find a simple diagnostic protocol for the ACR on bluesea.com.

As a side note, I had to send my first Smart Guage back to Balmar which they promptly replaced. I believe the voltages it displayed were correct, however, the display would 'freeze' after 2-3 battery charging cycles, so it never was able to 'learn' my batteries. I put the new one in 2 days ago and am in the process of doing a few discharge, recharge, discharge, etc cycles to test it.

My point is, if the voltages you quote below haven't been verified with another known reliable meter, double check them. I guess that's what you'll do with your clamp on gauge next week.

Let us know what turns out.

dave

 

[knotflying]

I agree with Dave. I would place a multimeter directly at the batteries and confirm that the voltage matches what you are reading on the other gauges.
Next
Make sure all connections are clean and no corrosion. That means ground to engine, wire on alternator and all connections from there back to battery. Check your belt also. Make sure it is tight and turning the alternator.
I would then start engine and with multimeter at battery terminal check voltage.
Still no good?
Check that your relays are on and functioning. If you suspect it may be your relays I would check the voltage before the relay to see what you are getting from the alternator. If you are still no good then it is either a bum regulator or alternator. I think, that these alternators have an internal regulator, so if that is the case you probably have to change out the alternator.
Let us know how things progress.

 

[Hydraulicjump]

Thanks you all. That sounds like a plan. Chief suspect is the alternator, since I am not seeing voltages anywhere near 14+v on the initial charge of the engine battery.

Will report back in a couple of weeks.

And my Balmar Smartgauge is going to have to go back as well. It will no longer let me get into the set up mode. Hmmm. This is usually a reliable company.

Jeff

 

[SGIDAVE]

Thanks you all. That sounds like a plan. Chief suspect is the alternator, since I am not seeing voltages anywhere near 14+v on the initial charge of the engine battery.

Will report back in a couple of weeks.

And my Balmar Smartgauge is going to have to go back as well. It will no longer let me get into the set up mode. Hmmm. This is usually a reliable company.

Jeff

Hello Jeff,

I have a 21EC so my experience, battery wise, may be different from what you should be seeing. I have a group 24 starting battery with (2) 6V golf cart batteries in series serving as the house bank. They are connected via a Blue Sea ACR. Until recently I had the alternator charging wire running to the start battery. When in that configuration, the start battery would reach the necessary voltage in 2-4 minutes after startup to cause the ACR to close thereby connecting the start and house banks. This ACR activity always occurred whilst the engine idled at the dock before getting underway. I could ALWAYS hear the Yanmar idle speed change as the alternator started putting out all it could to the newly connected house bank. Like the engine was taking on a new load. Anyway, until and for a little while after startup, the battery voltage (or charging voltage) was 14-14.4V. After doing some reading on Compass marine, I decided to switch the set up and now have the alternator output (charging wire) connected the HOUSE bank. In my rather tiny battery situation, it probably doesn't make much difference.

dave

 

[Kaisardog]

first thing i'd do is check tension on your alternator belt. if belt tension is too loose, you may have some belt slippage especially when engine and alt are cold. as engine warms up, the alternator does too. so an alt on a hot engine with tighter belt tension will show better charging after warm up.

the second thing i'd do is get a an ac clamp on multimeter and measure the charging amps off your alternator. there's a small diagnostic book on alternators that you may find helpful. (sorry I can't remember its title, i carry it on the boat .) if you can isolate the problem to the alternator you'll be able to get a handle on solving this weird charging issue.

 

[NorthernFocus]

As someone already mentioned, first and foremost make sure your instruments are accurate. Use a handheld meter directly at the battery terminals to compare with you panel reading before getting too carried away fixing something.

 

[Hydraulicjump]

Hey all. Thanks for the great advice here. I talked with Yanmar Marine yesterday about this, including the bizarre voltage readings. Their thinking is that the voltage regulator is showing the first signs of going. Rare, but it happens. Good news is that this is unlikely to leave me dead in the water and all is good as long as I don't need to spend multiple nights on the hook. Bad news is that I have to pull the alternator and make a choice: replace or rebuild. They said the alternator, given this weird behavior, may well pass the bench test and to insist on multiple tests to count the number of failures. My inclination is to take it to an alternator shop since the replacement alternator is $1550!

Any advice on removing this beast from our cramped compartments?

and then there was this morning.....

I believe a priest may be needed. Woke up in the dock hooked up to shorepower and, get this, the engine voltage was at 12.85v and the house at 13.2. That indicates that the ACR's are not connected. I turned off the shorepower and reconnected to restart the ProMariner charging sequence and the house jumped to 14.4v while the engine stayed at 12.85!

So close to Halloween. When I get back down to the boat I will swap the engine-house and house-thruster ACRs and see if the same thing happens. That is a first, by the way, in weird electronics. Could it be that the ACR that links the engine and house batteries is somehow the source of this problem? I have checked output from the alternator and it matches the readings on the battery monitor, morningstar monitor and Balmar Smartgage. Or is there a fuse I am missing somewhere?

Jeff

 

[SGIDAVE]

and then there was this morning.....

I believe a priest may be needed. Woke up in the dock hooked up to shorepower and, get this, the engine voltage was at 12.85v and the house at 13.2. That indicates that the ACR's are not connected. I turned off the shorepower and reconnected to restart the ProMariner charging sequence and the house jumped to 14.4v while the engine stayed at 12.85!

So close to Halloween. When I get back down to the boat I will swap the engine-house and house-thruster ACRs and see if the same thing happens. That is a first, by the way, in weird electronics. Could it be that the ACR that links the engine and house batteries is somehow the source of this problem? I have checked output from the alternator and it matches the readings on the battery monitor, morningstar monitor and Balmar Smartgage. Or is there a fuse I am missing somewhere?

Jeff

HEllo JEff,

Where do the leads from your onboard charger go? By that, I mean, WHICH batteries receive direct charging (NOT via ACR)?

I would think your START and HOUSE banks would get their own charger leads. If so, then the ACR only factors into the situation when underway and the batteries are being charged by the now-suspect alternator.

While the voltage regulator (VR) may not DISABLE you, it can cause other damage by outputting TOO MUCH voltage. The readings you have seen so far sound too low, but as the VR fails, you could also see higher readings that the ACRs wouldn't like (and stay open) as well as other 12VDC equipment which might get unhappy or HOT if supplied with too many volts.

Also, are the inline fuses from your on board charger OK?

The line from the ALTERNATOR is not normally fused but I've read some experts who make a good case for protecting the wire with overcurrent protection.

dave

 

[Hydraulicjump]

Thanks Dave. All good suggestions. I will run this down when I am on the boat next week.

 

[Hydraulicjump]

I may be shooting for the longest post on one boat's unique problem.

Dave, I had a coat and tie on most of this week that precluded monkeying with the boat. But here is what I know.

Turn on shore power and the house battery jumps up to bulk charge. The engine battery does not budge.
Turn on the Blueseas battery switch for the house batteries, nothing changes. But include the Blueseas battery switch for the engine, the ACR's connect and the engine battery voltage jumps to bulk charge, with both eventually settling down to float (13.2v). All connections to battery terminals appear ok.

I looked for a specific fuse between just the ProMariner and the engine battery but could not find it. All other fuses (the gaggle of fuses hanging out of the Blueseas switches) passed a visual test, but i have yet to test them all with the multimeter.

While connecting the engine and house batteries through the ACR's on the Blueseas switches is an easy workaround, I really wonder why the ProMariner charger is not charging both directly.

The alternator issue awaits removal and a free weekend.

Jeff

 

[SGIDAVE]

I may be shooting for the longest post on one boat's unique problem.

Dave, I had a coat and tie on most of this week that precluded monkeying with the boat. But here is what I know.

Turn on shore power and the house battery jumps up to bulk charge. The engine battery does not budge.
Turn on the Blueseas battery switch for the house batteries, nothing changes. But include the Blueseas battery switch for the engine, the ACR's connect and the engine battery voltage jumps to bulk charge, with both eventually settling down to float (13.2v). All connections to battery terminals appear ok.

I looked for a specific fuse between just the ProMariner and the engine battery but could not find it. All other fuses (the gaggle of fuses hanging out of the Blueseas switches) passed a visual test, but i have yet to test them all with the multimeter.

While connecting the engine and house batteries through the ACR's on the Blueseas switches is an easy workaround, I really wonder why the ProMariner charger is not charging both directly.

The alternator issue awaits removal and a free weekend.

Jeff

Hello Jeff,

Let's see, you have a 'START' single battery bank; a THRUSTER single battery bank; and a HOUSE bank (of TWO batteries?)? I'm not clear on how the R27 is set up battery-wise OR how the batteries are connected. If your Promariner is a 3 bank charger, then THREE of the boat's batteries should have a pos lead coming from the charger. This lead should be a 10GA RED conductor with an inline fuse within a few inches of the battery's pos terminal.

Let us know what you find.

dave

 

[Hydraulicjump]

Success!

To save wading through this long thread, my 2011 R-27 would start fine, but the alternator was clearly not delivering sufficient juice to the start battery. To make things complicated, it would jump to normal charging voltage right after start, but then slowly decline in voltage (over the period of 20 minutes or so) to 12.8 and then hold there for a while until it started declining again. Sometimes I could get it to charge up if I turned off the engine and started it again. But eventually it would go through this step decline.

First, like the electrical idiot that I am, I didn't realize that the "pause" in the decline was basically when the alternator was no longer putting out anything greater than the voltage of the start battery. At that point, the battery is basically charging the alternator.

Second, after testing everything else, talking to Yanmar, stumping the Ranger Tugs staff at the Rendezvous (lots of shrugs and the dreaded "never seen this before") I zeroed in on the voltage regulator. In an earlier thread I described the dead simple removal of the alternator. The shop bench-tested it and told me it was fine (it only shows signs of bad after about 10 minutes of running), but I had them replace the voltage regulator anyway. $30 part, $30 labor. Put it back in and, voila!, all back to normal.

So, if you get really goofy fluctuating voltages on your engine battery, but the alternator appears capable of putting out 14v, then suspect the voltage regulator. It takes very little time and money to have a shop do the replacement.

Hey, when do you do a repair on a boat and come in less than $100?

Success (for now)!

 

[SGIDAVE]

Hello Jeff,

That's a satisfying end to your battery charging/alternator problem. Thanks for posting back.

I've seen "external" voltage or charge regulators to be installed aftermarket on diesels like on the Ranger Tugs. I guess the idea here is that these would give you multistage intelligent charging. I wonder if something like that would work in your situation - NEXT time 😉

dave

 

[Hydraulicjump]

Thanks Dave. That was plan "B", but this fix worked. Lots of people use the external voltage regulators, particularly on older boats. Makes sense because the multi-stage charging should extend the life of the batteries. Still this cheap part did the trick, so all is well.

And truth be told, Andrew did say in an email last September that he thought it might be the voltage regulator, even though this is uncommon. He was, darn it, right again...