battery and battery charger

DanW

Hello,

I'm hoping someone with lots of battery knowledge can help me out. Last year, I purchased a new-to-me 2002 FV 342 and my mechanic put in a new battery charger (Pronautic 1230P). I have 3 banks - 1 battery for port engine, 1 battery for starboard engine, and 2 deep cycle batteries for house. I frequently anchor out for 1-2 nights. My house batteries are draining quickly (down under 10 volts) - in about 6-8 hours running two fridges and the stereo system. Running the generator for a couple of hours doesn't seem to be recharging the batteries much and while the generator is running, the voltage is only around 12.5 volts. If it's charging, shouldn't it show a higher voltage?. Only when the boat sits in the slip connected to shore power for a week are the house batteries back to "normal." Even then, when I disconnect from shore power, I'm showing 12.4 volts. When I had my Sea Ray with a similar set up, I could go a couple of days on the batteries (only one fridge though) without needing to recharge using the generator.

The two engine batteries are flooded cell. The house batteries are "maintenance free". I assume they are maintenance free flooded. The mechanic set the charger for flooded batteries and I wanted to know if that is the right setting? or if there would be any problem having flooded and maintenance free on the same charger set for flooded? The mechanic did a load test on the batteries and found no problem. Could the charger not be fully charging the batteries for some reason?

Thanks,
Dan

LaRea

Are you reading battery voltage from the meter at the electrical panel?  Maybe there's a problem with the meter.  Try reading it directly from the batteries using a multimeter, and see if you get a different answer.  

Next, remove the cables from the batteries, and check them for corrosion.  The connectors and posts should be clean and bright.  If not, polish them with emery cloth.  

How old are the house batteries?  Most people get 3-4 years ... 5 at most.  

Your setup sounds fine to me.  You should be able to go a full day, maybe run the genny for an hour in the evening.  The voltage will be low by morning, but not 10 volts.  

Handymans342

Replace the battery isolator if it’s original. 

Dream_Inn

Yes, if the batteries are 4+ years old, they are most likely done.  If not, taking them down to 10 Volts will usually kill them as well, they aren't made to do that often.

Check connections and check output of charger as well.  it should be outputting over 13V.  Also make sure the charger is set up for the correct type of batteries you have. Pronautic is a good charger (I have one as well).

DanW

I am reading voltage at the panel because my back is killing me right now and I don’t feel like climbing in to test at the batteries. But I understand the panel may not be accurate. Batteries are only a year old and posts are clean. I’ll double check the connections. 

The battery isolator is original. I hadn’t thought about that. I’ll see about replacing it. 

Thanks for the suggestions. I’ll do what I can and talk to the mechanic again too. 

Thanks! 

Dan

Liberty44140

Agree the panel gauge is more of a reference than a rule. Sorry about your back, but either you or a friend are best off to test the batteries directly. 

DanW

Friends that are willing to crawl into the bilge? Do those exist? Haha! Yes, I'll get someone to help me and we'll figure it out. I'll also talk to the mechanic again. Good mechanics are hard to find, so I wanted to get some opinions before I call him out again. Maybe point him in the right direction.

Thanks!

Handymans342

DanW said:

Friends that are willing to crawl into the bilge? Do those exist? Haha! Yes, I'll get someone to help me and we'll figure it out. I'll also talk to the mechanic again. Good mechanics are hard to find, so I wanted to get some opinions before I call him out again. Maybe point him in the right direction.

Thanks!

You need a smart monkey

Cableguy Greg

I just went thru chasing down charging issues. I ended up replacing my battery charger and isolator. The isolator was good, but the battery charger was shot. It was telling me that I had a full charge when in fact they were at 5 volts. I replaced the charger and my house batteries are lasting longer than they have in a while. 

Liberty44140

Lol they do exist. My buddy has a 40 Ray and while I fit in to his binge, he most certainly does not. So a few times a summer I don’t mind walking over to his dock and cleaning out his ac strainer, I even changed his freshwater pump last summer. He takes good care of me at the bar after but I’d help him anyway...