Battery Question - Mystery.

[rocklobster]

I have a question about batteries in my boat that is a little strange to me. Here are the specifics.

2020 C28
Batteries about 2 years ol, original with boat.
Sealed AGM batteries
Never once did I run any of my batteries down. House battery was taken care off and never drained below working V.
Boat stored in my yard this New England winter with 110V shore power
Battery charger built into the boat was on all winter (figured this would keep the batteries trickle charged in the cold)
At start of fall storage, all batteries banks measured 13.5V.

Go to start boat in the water today, Volvo was cranking over but very slowly and wouldn't start. Hydraulic Lift on hatch also noticeably slow. Tried turning on crossover, no difference.

Panel showed:
Bank 1 - 10.5 V
Bank 2 - 13.5
Bank 3 - 13.5.

I removed the two weak batteries on the starboard side which in the manual are called the house batteries. The wires on them also labeled nicely as house. All good. When removed, they measured 10.5 and 11.5 V.

Questions:
A) Why would the engine not start when the house batteries were dead? The engine battery on port side measured 13.5V. Shouldn't that start the engine?

B) I'm assuming batteries should last more than 2 years. Did my winter plan above have a flaw (e.g. bilge pump cycling every 5 min or built in charger doesn't charge all 4 batteries?)

C) What do you guys do in winter storage

 

[Capt’nKarl]

Your logic seems sound to me. It doesn’t make sense why the battery in bank one was low. Is your battery charger set for AGM battery charging? I store my boat on the trailer plugged into shore power with the battery charger on( set for flooded batteries) and so far have not had any issues. My charger is designed to charge three battery banks and my batteries are 3 years old. Bank One is the HOUSE BANK composed of two deep cycle batteries. Bank Two is a single ENGINE battery and Bank Three is a single bow thruster battery. Did you try to start the engine using the emergency parallel switch? I’ll be curious as to what others say.
Karl

 

[knotflying]

You may have two different issues. The house bank is obviously low. Was charger charging? The relays will cut out a weak bank if it drops too low. There are a few things running in the background when the switches are off.

Are all the connections on engine battery clean? Also connections to starter clean?

Are batteries labeled correctly? trace them out to make sure.

 

[rocklobster]

Thanks guys.....answer to your questions:

Is your battery charger set for AGM battery charging? ------Not sure. Assumed it was set properly at Cutwater factory. How do I check this? Is it a switch on the charger?

Did you try to start the engine using the emergency parallel switch? ------Yes, no change. Didn't help.

Was charger charging? -------- I thought it was but not sure How I would check this.

Are all the connections on engine battery clean? -----Yes. Very clean and tight.

Also connections to starter clean? ------Not sure I need to check.

Are batteries labeled correctly? trace them out to make sure. -------- The labeling seemed to match the manual layout with house batteries to port. Also labels on port side said genny, thrusters and engine. All seemed to make sense. I could try to trace them but not sure I'd know where each should go.

 

[BB marine]

A couple of thoughts and questions.

Bank 1 is house battery ?

When you had 13.5V at the starter battery I assume this was with the charger on. When the charger is turned off for 30 minutes what is the starter battery voltage? If the starter battery voltage is 12.7 or higher at this point that would indicate it is fully charged and should start the engine.

When you tried starting the engine was the crossover switch on? When using the crossover switch you are combining the house bank to the engine bank. If the house bank is dead this will cause an amperage draw to the start battery before trying to start the engine. Now try to start the engine with one good battery and two dead batteries connected. If the engine battery was at a full maximum charge it should have started the engine but if it was at 12.5 volts and connected to the two batteries at 10.5 volts that may be enough to cause a starting issue.

My advise is to fully charge all batteries using the Promariner charger. It has 3 outputs. After a couple of hours of charging all battery banks should be at or above 13.0V The ACR's should have green lights lit. When you check the batteries at the analog meter at the breaker panel you should see all batteries reading the same. Now turn the charger off make sure all battery switches are off. Let the batteries sit for at least a 1/2 hour. Check battery voltages at the analog meter. All batteries should be sitting at 12.6 to 12.8. If you see a bank that is less than this remove the battery terminals from the batteries and load test each battery to see if one or more of the batteries in the banks is bad.

One bad battery over a winter of charging all the batteries together could cause damage to all of them. The Promariner charger has 3 individual outputs. Once one of the batteries in the banks reaches 13.0 Volts for 3 minutes it will close the ACR's now all batteries are connected. If one battery has failed this will cause the charger to continually charge at the rate needed to fully charge the failed battery. This may cause an over charge to the rest of the batteries. I am stating this because it happened to me. I had a bad house battery. I kept the boat in heated storage and the charger on. Midway thru the winter I was working on the boat in the building. The batteries in the boat were overcharging and cooking, giving off a terrible smell rotten eggs. (hydrogen sulfide from over charging the batteries.) When I realized this I found the culprit but I had damaged all the batteries and had to replace them. The boat was delivered in April 2016. I replaced all batteries February 2019. The batteries were manufactured in June of 2015. Basically 3 seasons of use 4 year life. One bad battery.

May or may not be your issue. don't over think it. Load test each battery after a charging. I believe that will tell the story. If the batteries check out good. Then you further your troubleshooting. If you find one or more batteries bad. I would bite the bullet and replace all.

 

[Kevin Lamont]

I have a question about batteries in my boat that is a little strange to me. Here are the specifics.

2020 C28
Batteries about 2 years ol, original with boat.
Sealed AGM batteries
Never once did I run any of my batteries down. House battery was taken care off and never drained below working V.
Boat stored in my yard this New England winter with 110V shore power
Battery charger built into the boat was on all winter (figured this would keep the batteries trickle charged in the cold)
At start of fall storage, all batteries banks measured 13.5V.

Go to start boat in the water today, Volvo was cranking over but very slowly and wouldn't start. Hydraulic Lift on hatch also noticeably slow. Tried turning on crossover, no difference.

Panel showed:
Bank 1 - 10.5 V
Bank 2 - 13.5
Bank 3 - 13.5.

I removed the two weak batteries on the starboard side which in the manual are called the house batteries. The wires on them also labeled nicely as house. All good. When removed, they measured 10.5 and 11.5 V.

Questions:
A) Why would the engine not start when the house batteries were dead? The engine battery on port side measured 13.5V. Shouldn't that start the engine?

B) I'm assuming batteries should last more than 2 years. Did my winter plan above have a flaw (e.g. bilge pump cycling every 5 min or built in charger doesn't charge all 4 batteries?)

C) What do you guys do in winter storage

Hello,

I would agree with Brian above, ensuring the batteries are fully charged, checking ACR's are turning on when needed and performing a load test. Like Brian said letting them sit for 30mins without any load might give you a clue into what the issue is, have seen batteries fail prematurely. Hope this helps.

Thanks,

 

[rocklobster]

I think your right Brian. I had the two house batteries load tested today and they are shot. The guy who owns the battery shop, who is an acquaintance, says he see it often with the brand of battery. Not the top of the line battery. Dead in 2 years is not uncommon on the cheaper brands.

I purchased 2 AGM batterias, $260 each. Will install them tonight.

I need to check that the in-boat charger is setup correctly but I think it probably is. I bet one went bad and over charged the other over the winter.

Joe

 

[j&lgray]

I had a similar experience when I did turned on the rotary battery switch from ON to OFF.

On my first tug, the battery charger would charge the batteries when the battery switch was OFF. On my second tug, the factory had changed the wiring and when I turned the switch to OFF to conserve the batteries, it also prevented the batteries from receiving a charge from the battery charger. I ran the batteries down to the point where they had to be replaced. Now, my third tug (a 2012 model) the wiring is like my first one.

Lesson learned: Do not make assumptions about the wiring of the charging circuits. Verify before the boat is stored that the battery charger is ACTUALLY charging the battery banks.

 

[pleeson]

Now you've replaced some batteries I suggest that you check the charger setting. There is a manual in your factory bundle. It's a trick to see the indicator lights but I use my phone camera to get a good view of what is what down in the lazerette. I wouldn't assume that the setting is correct.

 

[rocklobster]

Good point. With the phone and a twisted neck, I was able to confirm the AGM symbol on the screen for each bank. Always good to check!