charging problem with new batterie

[richk]

I just upgraded my house band to 3000 AH. After first doing this I didn't detect a problem. A few days agp I had the battery charger running and energized the refrigeration. Next day the voltage plummeted to 10.1 VDC.
Ideas?

 

[JamesG161]

What battery charging System do you have?

Jim...

 

[Davidasailor26]

Tell us more - What kind of batteries? (What chemistry, sizes, etc.) When you say you upgraded the bank did you just add new batteries in parallel with the old, or did you replace everything? Is it really a 3000 AH bank? That’d be massive for a 37’ boat. What kind of charger do you have? Was it still on the charger when it read 10.5V, or what loads had it been subjected to leading up to that?

 

[jviss]

Wow, do you really mean 3000 Ah?

 

[dlochner]

I just upgraded my house band to 3000 AH. After first doing this I didn't detect a problem. A few days agp I had the battery charger running and energized the refrigeration. Next day the voltage plummeted to 10.1 VDC.
Ideas?

Really need more details. And a 3000 ah bank would be 30 Group 31s. I suspect a typo.
What kind of batteries? What kind of charger?

 

[artboas]

I call BS on the 3000 aH.

 

[Stu Jackson]

If they are wet cells, have you broken in your new batteries?

Breaking in New Wet Cell Batteries: "Breaking In" New Wet Cell Batteries

 

[Don S/V ILLusion]

Ideas?

lots of ideas.

This is a very helpful and knowledgeable group but it requires some level of responsiveness on your part to the questions posed to you. Too many times, someone asks a question devoid of any background info and then disappears while people waste their time trying to help. The consequence being people are less inclined to respond to others.

Don‘t be one of those!

 

[jviss]

I fairness, it's only 16 hours since he asked the question.

 

[ggrizzard]

Good point Jviss.

 

[richk]

Sorry for the delay guys..
have been busy with non-boating things.
I did none of the battery work...merely paid for it. I have a Pronautic 1240P. All batteries were replaced by new ones, including the starting one. The house bank is the problem. After the install with battery charger on I energized the refrigeration. The next day house voltage down to 10.2. As most of you surmise the house system can't be 3000 AH. I was told the house bank are AGMs. They are group 31s.

Still puzzling I am
Rich in Annapolis

 

[kappykaplan]

Are you sure the battery charger is putting energy into the house batteries?

 

[dlochner]

There should be a fuse on the battery charger positive cable, check to see if it is still good. Then call the guy who installed the system and ask, WTF? He should make it right. Taking an AGM to 10.5v is not good for any battery much less an AGM. In your area, Peter Kennedy is the goto guy for electrical work.

 

[Davidasailor26]

What was the voltage reading when the charger was turned on? That should help figure out whether it’s really charging. If not the fuse dlochner mentioned would be a good first place to check.

Get a multimeter if you don’t already have one to start checking battery voltages and troubleshooting further.

In any case try to get the batteries to a full charge as soon as possible. The AGM’s will not be served well sitting at that low state of charge.

If you have 3 Group 31’s it’s probably 300 Amp Hours, not 3000.

 

[richk]

I've got the charger on and it says it's in conditioning mode. The DC output levels are 14.5 v and 0.0 amps. If this is why it's not charging how long might it take before it starts charging?

 

[Davidasailor26]

According to the manual at https://www.promariner.com/-/media/inriver/63110_USE.pdf?modified=20230322141015 “conditioning” is what we commonly call absorption mode - it means the charger is trying to charge the batteries up to full. It’s pretty unusual to have 14.5 V and 0 amps though. That means the batteries are already full. Either they just got to full and the charger is about to go down to float / Auto-maintain mode or something else is awry. My guess is the charger is holding its outputs at 14.5 but that voltage isn’t getting to the batteries due to a bad connection, blown fuse, etc. To test that check the voltage at the batteries themselves and compare that to what the charger shows as its output.

 

[richk]

Ok thanks Mermike. It's too tight a fit to pull a. fuse. I'll have to visit hardware store and get a puller.

 

[dlochner]

The Pronautic Chargers always start at the programed max voltage and 0 amps. Once it senses a battery it in creases the current to max current. So long as the battery can accept the max it continues and then tapers the current until float voltage.

If the reading stays at 14.5v and 0a for more than a few seconds the charger is no seeing the battery.

According to the manual at https://www.promariner.com/-/media/inriver/63110_USE.pdf?modified=20230322141015 “conditioning” is what we commonly call absorption mode - it means the charger is trying to charge the batteries up to full. It’s pretty unusual to have 14.5 V and 0 amps though. That means the batteries are already full. Either they just got to full and the charger is about to go down to float / Auto-maintain mode or something else is awry. My guess is the charger is holding its outputs at 14.5 but that voltage isn’t getting to the batteries due to a bad connection, blown fuse, etc. To test that check the voltage at the batteries themselves and compare that to what the charger shows as its output.

The Pronautic series of chargers always start with the max programmed voltage and 0a to sense if there is a battery attached. The charger then puts out the max charge. If the voltage stays at the programmed level, the current begins to taper off. If it can't maintain the max current and max voltage, then the voltage drops to maintain the max current (constant current stage), until the voltage reaches the programmed absorption stage (constant voltage) at which point the current then tapers off until the float stage is reached.

If the charger shows 14.5v and 0a for more than a few seconds, the charger hasn't found a battery yet. This points to a disconnected cable, a blown fuse, or a switch of some sort that interrupts the circuit.

 

[richk]

Problem found...main charging system breaker tripping. Gonna replace it. House bank is 630 AH.
Thanks for all your help.
Rich

 

[dlochner]

Problem found...main charging system breaker tripping. Gonna replace it. House bank is 630 AH.
Thanks for all your help.
Rich

This is the breaker on the DC+ from the Charger? If so, the standard is to put in a breaker at 1.5 times the charger's output, which in your case would be 60a. If the installer put in a smaller breaker, then I would go over the whole install very carefully.