a couple of (maybe related) electrical symptoms

[mr_f]

Anyone have some guesses on the following? I am having some peculiar issues with my inverter/charger and with my VHF. Both complaining about things that sound like they aren't getting enough power.

A bit of background: the boat is new to us (less that 2 months). It surveyed fine, and everything seemed fine on our sail to our home port after purchase. The house bank is quite old (7 years?). It is comprised of three ~100 amp hour AGMs. If I am interpreting things correctly, they appear to still have some life. After drawing them down 80 amp-hours (based on the Link10 battery monitor), they still show around 12.35V. I have applied a fair amount of load without noticing anything very odd. I have not tried real load testing.

Possibly related to the problems with the charger and VHF: Within the first couple of days after bringing her home, a large lightning storm hit our marina. At least 9 boats on our dock are having most of their electronics replaced.

The only immediate symptom we noticed was our Link10 battery monitor started slowly counting up amp-hours (several hundred amp hours) until I pulled a fuse (I tried resetting it and cycling charger and cursing a bit first). Reconnected the fuse and all seemed OK.

Later discovered the wind gauge no longer worked. Replaced mast-head unit and all is well. All other electronics (with the exception of the inverter/charger and VHF) seem fine.

Now on to the two mystery problems:

The inverter/charger (ProSine 2) gives a "Low Bus Voltage" error and tries repeatedly to restart itself when first connected to shore power. It will not successfully start charging until you use the configuration menu to clear faults. Sometimes it takes 2 or 3 tries to clear the fault. Very rarely it starts with no error. Either way it seems to work fine once it starts. Based on advice from the company, we reseated the connections and measured the voltage at the battery and at the inverter/charger and voltage appears normal, but fault continues to occur. Company says this error is from the DC side of the system. I did not get the error the first (and only) time we plugged in before the storm.

This weekend, I was unable to transmit on the VHF (ICOM IC-M502) with it set to 25 watts. Received "Low Battery" warning on the VHF display every time I pressed the transmit button. Link10 and panel both showed about 12.4V at the time. No large drop in voltage while attempting to transmit. Transmitting on 1watt worked fine. I can't say whether this symptom is new because I have not had reason to use the radio since the storm. (Although I did test it at the dock at some point and it worked fine, but I was hooked up to shore power and charging at the time. It was tested during survey, but I don't remember whether it was at the dock or during the sea trial.) I just tested with the charger off and it worked, but batteries are fully charged at the moment.



So, any useful advice on diagnosing?
Is the ProSine shot, or can it be used in this condition until it fails?
How can I tell if the VHF is really not getting enough power, or whether it is confused (needs repair/replace)?
Am I wrong in believing the batteries have some life left in them? (I know they are getting old.)
If I do need to repair/replace some or all of this, what order? Would it be wise to replace the batteries (assuming they don't load test well) to see if the other things get better? Should I replace the misbehaving charger before investing in new batteries?

 

[Forrest15112]

Measure the voltage on the wire as close to the VHF transceiver (trx) as possible. Most meters have sharp pointed leads that can safely pierce the shielding on most wire without damaging it. It should be very close to the same voltage as the supply. When you key the radio, if the battery is too weak, the voltage will drop significantly on both the supply and at the trx. If the power wires are damaged or corroded, the supply will not change, but the measurement near the trx will drop.

If you determine it's the wire and not the trx, check both the positive and negative return for corroded connector, butt splice, etc.

What about when the engine is running? Your voltage and available current should be up if the alternator and regulator are functioning properly.

 

[mr_f]

Thanks for the input. I should have thought about testing again when we started the engine. Considering it works at the dock, I assume it will, but I certainly should check. And you're right, I should check the voltage at both ends. We did for the inverter/charger, not sure why I didn't bother for the VHF. I will do both this weekend.

Any thoughts on the ProSine or battery life?

 

[kenn]

Forrest has it exactly right - measure voltage right at the VHF when trying the transmit at 25 W, If it's dropping there but the panel voltage remains constant, there's a poor connection somewhere between the panel and the VHF.

Any thoughts on the ProSine or battery life?

Monitor the voltage at the charger output when it starts up, and also at the batteries. The voltage should be shooting up to 13.5 or higher when charging.

Also get the batteries tested if possible. The automated battery testers give the best picture, but you can also get some good info from a load-tester.

 

[mr_f]

Thanks for the additional input. I may not have described the issue with the inverter/charger sufficiently. Once I manage to clear the faults, it does start charging normally. Batteries receive something in the 14V range for some time, and then drops to something in the 13V range. I have checked both ends and no substantial voltage drop.

The problem is with getting it to start charging. My understanding (which is quite limited) is this particular charger won't actually charge a totally dead battery (seems like a poor design) because it needs some juice from the DC side to get started. I did not understand if this was some sort of a fail-safe, or that it needed the power to run part of the controller.

From what I gather, the error I receive (Low Bus Voltage) should only be triggered if there is not enough power on the DC side to start up. But I measured the voltage both at the batteries and at the charger end and both should have been sufficient. (For instance, I can trigger the error even when the batteries are full. If I turn off the charger when the batteries are fully charged, then turn it back on, I get the error and have to clear it to start the charger again. I measured 12.7ish V at both ends: battery and charger.)

 

[Stu Jackson]

mr f,

Wadr, you have only begun to do a true forensic examination of your issue.

Yes, measuring voltage is one part of the equation.

You need to take it section by section, step-by-step.

Your area has had a lightning strike.

Your batteries are old. Have you done a hydrometer check on the cells? It sounds like you have a low battery fault. Right? If so, then one would expect that the inverter wouldn't work.

Your charger doesn't start up right away? Could be a dead cell in one or both or all of your batteries.

Isolate each battery in your bank, and try again.

I really believe you need to go back to basics, and attempt to isolate each portion of the components in your system to be able to isolate your issue.

All of the rest is just us guessing.

Good luck.

 

[mr_f]

mr f,

Wadr, you have only begun to do a true forensic examination of your issue.

That is why I am here. Hoping to get some help on how to do a more thorough diagnosis and get some opinions on how to proceed.

Yes, measuring voltage is one part of the equation.

You need to take it section by section, step-by-step.

Your area has had a lightning strike.

Your batteries are old. Have you done a hydrometer check on the cells?

I was not aware there was a way to use a hydrometer on AGM batteries.

It sounds like you have a low battery fault. Right? If so, then one would expect that the inverter wouldn't work.

As an inverter, it seems to work fine.

Your charger doesn't start up right away? Could be a dead cell in one or both or all of your batteries.

Isolate each battery in your bank, and try again.

This is worth trying. Will see what I can do.

I really believe you need to go back to basics, and attempt to isolate each portion of the components in your system to be able to isolate your issue.

All of the rest is just us guessing.

Good luck.

 

[DougM]

To me, the charging side of the question would be linked to the batteries as others have suggested. Regardless of the "apparent" condition of the batteries at seven years of age I would have probably contemplated replacing them about three years ago. The batteries' ability to fully charge deteriorates with time and cycling. If you have not done so, check the connections at the battery terminals and primary wires to be sure that they are tight, it's not unusual for them to either loosen up or develop a corrosion buildup on the posts.

That being said, and the fact that there had been a nearby lightning hit, an electrical spike might have cooked some of the electronics in the charger. It may appear to be providing the proper output voltage when looking at the unit itself, but in fact giving a false reading. Just a thought. If all of your other electronics are working, I would be inclined to concentrate on the charging circuit, while trying to isolate the problem. It's too expensive to go through the process of replacing parts one by one until the problem disappears. Often, if voltage drops below a certain level, some of the electronics will appear to not be working properly. A multi function display will usually be the first to show the symptoms.

 

[Stu Jackson]

In addition to Doug's good advice, check the negative ground at your engine. Remove it, clean it up and reinstall it. The ground often is a nglected but importnt part of the entire circuit. Good luck.

 

[mitiempo]

In addition to Doug's good advice, check the negative ground at your engine. Remove it, clean it up and reinstall it. The ground often is a nglected but importnt part of the entire circuit. Good luck.

Stu
I agree it should be checked but it should have no bearing on the po's issues. Alternator charging is not one of his problems and even removing the engine ground should not effect the inverter/charger operation.

 

[mr_f]

A bit of an update...

Battery connections are squeaky clean and tight (as is the ground connection at the engine). We drew quite a lot of power out of the batteries over the weekend with no sign of issues with them.

The voltage is fine at the back of the VHF, so the wiring seems OK to me. But I haven't been able to recreate the problem, so I guess for now I will just adopt a wait and see approach on that one.

The batteries seem to operate normally to me. They hold charge. They don't experience any sudden voltage drops when drawing reasonably large loads. Except for the isolated incident with the VHF, I have noticed no electronics acting abnormally. The batteries do seem to have somewhat reduced capacity but the capacity is fine for me at the moment and I am not sure I am interpreting my measurements correctly anyway. (I believe I should be able to draw around 150 ah before I am down to 50% state of charge (12.2-12.3V?). I can only draw around 80-100ah before that point, but I know that depends on other things like rate of draw.)

I am becoming more confident that the problem with the inverter/charger is a just that: some internal failure of the charger. I am open to other suggestions, but I don't know how to test anything more. Everything I have measured says the charger is doing the right thing once it gets started. It works up to a 14.7V acceptance phase. Backs off to a 13.6 float phase once current drops to low amperage. All of this is measured at the battery bank and the charger (and the panel, and the link10).

One oddity that I have discovered is that it seems much less likely to generate the error condition if I have used it as an inverter while away.

The question that remains is whether I should replace an expensive inverter/charger that seems to be working fine except it generates an annoying error condition when it is plugged in. I realize that a poorly behaving battery charger is a safety issue.

 

[mitiempo]

Having just recently visited and inspected an engine room electrical fire I would pull the inverter/charger. Borrow or buy a charger and install it and forgo the inverter for a while. See if the batteries and other items like the vhf act normally. Send the inverter/charger to a qualified shop for service.

The fire I visited caused a great deal of damage - almost all wiring and multiple shift/throttle controls had to be replaced, not to mention the mess the extinguisher powder left behind. If the owner had not been aboard the boat would have been a total loss.

If the inverter/charger needs replacing Magnum is a good choice and there are other good brands that do not start with the letter X.

 

[dilligaf]

Replace your battery

We replaced our battery bank (AGM) just before leaving the U.S. heading across the Pacific. We found the batteries are only good for 6 years with regular charging. We have been gone for 3 years and will be replacing them again in another couple of years because we charge almost daily. They will only take a certain amount of charges before they become weak.
I hope this helps
Bill