Charles battery charger is pegged

[Docrockit]

I dewinterized my main engines and they fired right up. No problems. When I shut them down, I heard a fan running in the engine room that I hadnt been hearing. It was the fan on the Charles 5000SP Smartcharger. The needle was pegged as far right as I have ever seen it. Past the 50 amp mark and the fan was on. I shut the charger down thinking I may have a battery gone bad. I use a pair of Odyssey PC2250 AGM batteries. They are only 3 years old. (The last pair lasted 12 years!) Both show 12.6 volts. I think the batteries are fine. Now I am wondering if my parallel switch at the helm (its original) may not be the culprit? Or the charger itself? Any advice on what to check?

 

[Reefgeorge]

What voltage do you have at the batteries when the charger is "pegged"?

Does your charger have an equalization mode that it started?

Why do you suspect the parallel switch, do you see that charging voltage at another battery bank not served by that charger?

You may not have an honest 12.6 volts. After a battery has been charging you have to knock off the surface charge with a moderate load for a short time then measure the battery voltage.

George

 

[Docrockit]

So, with the charger turned on with the needle pegged as far right as it can go, the voltages are 12.6 V on the port and 13.1 V on the starboard. Turn the charger off and both voltages dropped to 11.5 and 12.8. Disconnected the starboard battery to check the parallel switch. With the switch in neutral (middle) position, the port battery cant crank either engine. But the switch is working. The voltage on the port battery after these attempts...10.8 V. I now believe my port battery is the culprit. Is the charger sensing low voltage and just trying to do its job? Do I need to replace the battery or let the charger see if it can recover the low voltage? Thanks for your suggestions George.

 

[Boatsb]

Battery testers are worth their weight in gold.

Get a good one and remove all doubts

 

[jim rosenthal]

I would get a battery tester as Scott advised. I have not had particularly good luck with Odysseys and I think they are overpriced. If I were going to get AGMs I would get Trojan or Lifeline etc. More than likely the charger is okay, but find out about the batteries first. And you may have to replace both of them.

 

[Boatsb]

Odyssey makes some bad ass batteries. I put the group 31 2250 cca in a fire boat. Great choice and no issues except the charger needed some rewiring from a previous contractor that used 12 gauge wire for a 40 amp charger.

 

[jim rosenthal]

You have had better luck than me, then. Of several Odysseys, I have one left which is still holding a charge and working as it ought to. Allt he rest, in my boat, sooner or later failed on me and of course the warranty was worthless. I do have the one, in a Cobra, which is okay so far- a good thing, since the battery case is sized only for an Odyssey. If I want to install anything else, I will have to remove the battery mounts and fit something else to put a different battery in.

 

[Reefgeorge]

So, with the charger turned on with the needle pegged as far right as it can go, the voltages are 12.6 V on the port and 13.1 V on the starboard. Turn the charger off and both voltages dropped to 11.5 and 12.8. Disconnected the starboard battery to check the parallel switch. With the switch in neutral (middle) position, the port battery cant crank either engine. But the switch is working. The voltage on the port battery after these attempts...10.8 V. I now believe my port battery is the culprit. Is the charger sensing low voltage and just trying to do its job? Do I need to replace the battery or let the charger see if it can recover the low voltage? Thanks for your suggestions George.

So your port and starboard battery banks are on the same charger using two of the chargers 3 output banks?

Assuming that the answer is yes:

Most chargers don't actually have three separately controlled output channels so the charger looks at all three banks through isolation diodes and the output is driven by the most needy battery/bank. Your charger has a first stage bulk charging rate of 14.X volts so it sees that low battery and goes into high current bulk mode. It does not think that you are fully charged yet. I found this bank imbalance issue to be the reason for premature battery death of the starter bank which does not need all of that charging driven by the house bank. That and poor ventilation and the lack of a temp sensor at the batteries but that's a whole 'nother story. You need to get your batteries charged up and balanced and see what voltages you get after knocking off the surface charge. If you want to do a real battery test at that point a load test with a carbon pile/wirewound coil tester will do the trick. You can charge the low batteries eperately or let the charger address the entire array until the low ones come up. Just keep in mind that if those low battery(ies) are going bad you will be overcharging the other good ones. I don't know if that charger times out to keep from destroying the good batteries when one fails.

I have had very good luck with Lifeline and seperate chargers for each bank, along with upgraded ventilation and temp sensors on both banks. An advanced charger with actual seprately managed channels does the same thing

George

 

[Docrockit]

Brief follow up: I took the port battery out and carried it in to be tested. The voltage reading was 1.66 V. It said to recharge and then test. After 3 days of charging and testing, it was brought back to 13.1 V with over 1300 cca. It is now back in service in its Hatteras battery box. This time on the starboard side. So far, no issues but not yet put through its paces. The charger is acting normally. Time will tell. Still more than 1 year left on the warranty...

 

[jim rosenthal]

Interesting that it fits in a Hatteras battery box. Most of those boxes were 8Ds, and I didn't think Odyssey made an 8D.

 

[Boatsb]

The pc2250 is square about half the size of a rectangular 8d.