battery chargin' blues

[HukilauMike]

I went to charge my boat's battery last month (like I do every month over the winter), and it wouldn't take a charge. I took the battery back to BoatUS to see if it was dead, and they tested it. The result: it tested out as healthy, having more crank amps available than listed on the battery, but was at 75% of a full charge. I asked the clerk why it wouldn't take a charge and he told me that I needed to attach the charger cables to the big posts, not the smaller threaded posts as I had been doing. I went home and tried to charge the battery his way, and it still wouldn't take a charge. This is a new battery, purchased only last spring. Am I doing something wrong? Is the clerk spouting nonsense? What the heck is going on?

 

[Stu Jackson]

Have you considered...

that it's the charger that could be the problem, not the battery?Stu

 

[John]

Hope this helps

It should not matter which posts(ones with screw tteminals or regular posts) you attach to as long as the polarity is observed. Your batteries may have drained down to a low level and do not want to readily come back up. If the cell caps are removeable, check to see if you have water in the cells. Use distilled water only. Not knowing what capacity charger you have or if you are trying to charge two or more batteries at once, I am unable to advise you. however, most auto stores(chain type such as Auto Zone or Advance) have qualified battery testers on hand. They will place the battery on test for free and advise you of the condition.Or go to a reputable auto electric repair center where they deal with auto batteries as a business and get advice. In the end, you want to discuss this with a qualified individual. Good luck.

 

[David Williams]

Understanding Batteries

If you want to understand batteries, Interstate Battery Company has a great training manual. I have a Dallas phone number: 972-715-6661, and a note to ask for Kelly. They have two manuals, a light-duty and a heavy-duty. I have both; and they have the same basic information, except the heavy-duty manual has information about 24 volt starting systems...trucks. Be sure to read about battery sulfation. It is a product of time and state of discharge. It is hard to get a sulfated battery to take a charge. One must start the process at a high rate of charge, and it may not work on a badly sulfated battery.Of course, you need to be sure your charger is working. The key to stopping battery sulfation is to keep your battery fully charged at all times. We cannot do this while we are sailing, but it is a good ideal to keep a maintainer charger on the boat when not sailing. I have an Conductance Tester. I do not think that it is as reliable as a properly done load test. In fact, I think my 100 amp "toaster" works better than the Conductance Tester. In my opinion, a hydrometer used in conjunction with a carbon pile load tester is the only way to get a good reading on the condition of a battery.

 

[Jonathan]

What type Battery?

You don't mention the type of battery, lead acid, gel, or AGM? Nigel Calder has an excellent book: "Boatowner's Mechanical and Electrical Manual", and he explains not only about batteries, but how to determine what size and type of battery you might need, and your amperage and charging requirements.All three of the replies so far have made good points. My guess would be sulfation, due to either remaining partially discharged for too long, insufficiently recharged, OVERcharged, or a combination of all of them.Look into a small solar panel "trickle charger", which will keep your battery topped up through the winter.As for saving this one, Calder has a few tricks for bringing batteries back to their full potential.

 

[Paul S]

Did they/you check every cell?

Did you check the electrolyte in each of the cells with a battery tester? Could have one or more bad cell(s). what type of battery? Starting or deep cycle? wet cell, AGM, Gell? Type of charger?I was told not to charge the battery over the winter. Just leave it in the boat in the fall, water topped off, top off the charge...let it be. In the spring..check the water again and charge. Been working for me. As was mentione before...it could be a bad charger. Had that happen to me before. It doesn't matter what terminal to attach the charger....if it did..the battery would never get a charge from the alternator. get a battery tester (looks like an eyedropper with balls in it) I flush it out between cells with water to ensure I do not get a false positive charge reading. Check each cell.Got a Gell or a AGM? ....Not much you can do other than try another charger..or buy another battery. FWIW...I have always used tap water in my batteries. I generally get 6-8 years out of deep cycle batteries. No harm in using distilled. Yes it is technically better. But I do not think it makes a huge a difference as we are told. Paul

 

[jmcclain]

Take it Somewhere Else!

The statement that the clerk made about the battery posts should be your first warning. I would not rely on anything that he told you, or any test that he administered.

 

[Pete M.]

Nigel Calder...

One of the posters below recommends Nigel Calder's book on electronics. Does anyone remember when he was fitting out a new boat (think it was a Crealock 40, but not sure) and he was trying to convince his readers to do their commissioning? In the end, he burned up most of his electronics by installing them incorrectly. Being Calder, he just called the makers and asked for new ones -- gratis. He then had a pro install them. If this had been us, we would have wasted a lot of dough on dead electronics. Id be pretty careful about any electrical advice from this "expert."

 

[Seattle Scott]

As a follow up to Stu

What is the voltage meaured at the terminals w/the charger on and connected?

 

[HukilauMike]

more info

thanks to everyone for their input. Some more info for your consideration:the battery is one of the BOATUS house brand batteries. It was designed to be used as a starter battery for small to medium sized outboards. It is truly sealed, so there is no way to check water levels. When the guy at BOATUS checked it, it came up with more than 12 volts (I don't remember the exact reading) at the posts, at 75% of a full charge, and that it had more cranking amps available than it was rated to provide.

 

[Tom S]

Here are a couple of good links to battery sites

Here is the best one that talks to deep cycle and marine batteries the besthttp://www.windsun.com/Batteries/Battery_FAQ.htmhere is another good one http://www.uuhome.de/william.darden/I agree with a few others. We need more info, But in the end it kind of sounds like your battery charger is not working.What makes you think it doesn't take a charge? What parameters (Voltage or Current readings?) give you that feeling? Do you have an ammeter on the charger? Do you see current flowing out? Do you see the voltage level slowly rising? It can take a while for a good 3 stage charger to bring low batteries back up to 13-14Volts sometimes

 

[Seattle Scott]

Mike answer my question *grr

as the voltage at terminals when charging may rule out or confirm the issue is your charger not the battery.Also, when you say the battery won't take a charge, what are you observing?

 

[HukilauMike]

Take 3

I appreciate your help. Scott: I reread your question, and I see where my earlier answer failed. The only info I have on the voltage is from when the guy at BoatUS tested the battery. I don't have an instrument to check the voltage myself. My battery charger is a manual model with a meter (that goes from 0 to 6 amps) and two charge settings: a 2 amp setting for small (lawnmower, motorcycle) batteries, and a six amp setting for larger batteries. The instructions on the charger say to connect the cables, plug in the unit and charge the battery until the amp meter on the charger shows a number that is about 1/3 the setting of the charging switch. In my case, I would use the 6 amp setting on the charger switch and hook up the unit to the battery. Previously, the needle would twitch around a bit, but after five seconds or so, it would settle down at about 4. I would wait a few hours until the needle went down to 2 (1/3 of 6) and consider the battery fully charged. The last couple of times I went to charge this battery, the needle would sometimes twitch a little, but it really never moved off of zero. My assumption: the battery wasn't taking a charge. The same thing happened to me last year. I took the battery back to BoatUS, they tested it and confirmed it was dead and gave me a new one. With this battery, I took it back and they told me it was fine if undercharged. Both the voltage and the available cranking amps were good. Any help in diagnosing the problem?

 

[Stu Jackson]

Any help? Yes

MikeRead Tom S's references. It sounds like you're using a cheap car - type charger. It is killing your batteries. Read up on quality three stage chargers. Buy a multi-meter - less than $20 from Radio Shack, measure the things you need to know and have been asked, and read the earlier references to Ample Power about how to take care of your batteries. As I originally suspected, you have a poor (at best) charger.StuPS sorry to sound like I'm harping, but you have been given a lot of answers already - you need to do some work, now, on your own.

 

[Seattle Scott]

Mike, I'm with Stu again on this

get a multimeter. They are fun to play with. Set the selector dial to 12v DC stick the probes on the batt terminals, take a reading. 12.7 volts is full charge and 12.0 volts is almost dead. 12.4 would be accepable. Turn on charger and put probes on charger clips,( you are just testing the charger now) if you are not seeing something in the 13 -14 volt rage, chuck the charger. If you're getting 13-14 from the charger, hook it up to Batt and if you find increased voltage at batt terminals a couple of hours later(looking for 12.5 to 12.7 volts, with charger disconnected). If so, charger is OK but its meter is wacked. If you don't get a multimeter Stu and I aren't going to talk you any more ;D(grin).

 

[David W]

Hmmm my car charger

won't put out voltage unless it is connected to a battery. So I get no voltage by connecting multimeter leads to the alligator clips which could lead one to beleive the charger is not putting out voltage.Just thought it bears mentioning, the increased voltage( 12.5+ I would think) when it is is a likely indicator the charger is producing voltage when connected to the battery.

 

[Seattle Scott]

Hey David,

once you connnect charger to batt the voltage mesured at the terminals is either the batt, the charger or both. Or simply as you say, if no voltage at the charger clips, the thing ain't going to do anything.