Another electrical Dilema. Help!

[Prime Time]

Hi,
Maybe some of you have had this problem.

I have 6 x 6 volt power tech agm batteries wired as 3 groups paralleled of pairs in series for my house bank. The batteries have been connected to a 40 amp Charles charger for a few weeks and should be fully charged. The voltage only reads 12.6 v.

Checking the individual batteries, they read 5.8, 5.8, 6.2, 6.6, 6.6, and 6.6 from their individual terminals.

They are just 3 yrs old.

I wonder why 2 of them are substantially lower than the rest?
Is there any hope for them?

I have a 105 amp 8MR series Leece Neville alternator dedicated to my house bank. It looks like the one on Mainesail's page on changing the regulation from internal to external. My is internally regulated. With the engine running, measuring from the hot side of the alternator to the engine ground, I only had 12.6 v, matching the battery voltage. I adjusted the regulator setting a bit and got it up to 13.1. What would be optimal for?

 

[Don S/V ILLusion]

Charge voltage is a function of the state of charge so it's important for you to know that when you measure charge voltage, i.e., a depleted battery bank will show a higher charge voltage initially than a fully charged bank.
When you measured 12.6/13.1V, was the battery bank fully charged? If not, that's too low a charge voltage and it should show 13.5/14.5V.

Also sounds like two or three of your batteries are on their last leg and not doing the good ones any favor - you might want to take them out of line and measure charge voltage with just the good batteries before doing any more adjustment to the regulator.

 

[Prime Time]

Charge status

The house bank had been charging for a week when I made the measurements and by the meter, were not taking much amps.

I wonder if I just took the 2 worst and put them in series and just charged them, if they might recover?

 

[Stu Jackson]

We have no idea as to how well you maintained the fluid level in your house bank, nor do I personally have any trust in Charles chargers.

"With the engine running" doesn't help us to help you. What rpm? Cruise speed or just at idle?

The advice to isolate the potentially bad batteries and try the rest is a good start.

Have you checked the charger output voltage? Turn it off and then back on to see if it does bulk, absorption and float. Is it a true three stage charger?

 

[Prime Time]

response

We have no idea as to how well you maintained the fluid level in your house bank, nor do I personally have any trust in Charles chargers.

"With the engine running" doesn't help us to help you. What rpm? Cruise speed or just at idle?

The advice to isolate the potentially bad batteries and try the rest is a good start.

Have you checked the charger output voltage? Turn it off and then back on to see if it does bulk, absorption and float. Is it a true three stage charger?

The batteries are AGM, so no fluid to check. The Charger is fine. It is a 3 stage charger. In bulk stage charges at 14.1 volts. Practical Sailor liked this model sp-2000.

Engine was running over 2,000 RPM so voltage from the alternator should have been not been limited by rpm.

 

[Stu Jackson]

gotcha, missed the agm first time read. sorry

 

[Prime Time]

Nanopulser?

Has anyone used a nanopulser to rescue a sulfated battery?

 

[Bill Roosa]

wiring

the exact wiring of the batteries may be important
If the charger cables are not "across" the whole battery bank you can get into batteries isolated at the end that don't get fully charged.
If the charger cables are only "across" one (2x6v) battery the other batteries don't get charge "forced" through them. they get a kind of "leakage charge" that can be effected greatly by terminal condition.

Also make sure your terminals are clean. Dirty terminals are the cause of 99.44% of battery problems.

 

[Stu Jackson]

Has anyone used a nanopulser to rescue a sulfated battery?

Yes, just last month from this very website's chandlery. Too soon to tell. Do a search on nanopulser, there are some earlier discussions.

 

[Snotter]

My Charles charger destroyed batteries that were only 1.5 years old. The charger was nothing more then a transformer, diodes (2), and capacitor. Also, the charger didn't have any fuses. So, if your charger isn't connected through fuses to your battery, you have a potential for an electrical fire. My charger melted down. I came to my boat to find pools of plastic insulation underneat long runs of wire and charred wood where ever the wires touched. Many adjacent wires were damaged. Do yourself a favor and deep-6 Charles.

 

[catsailor]

the exact wiring of the batteries may be important
If the charger cables are not "across" the whole battery bank you can get into batteries isolated at the end that don't get fully charged.
If the charger cables are only "across" one (2x6v) battery the other batteries don't get charge "forced" through them. they get a kind of "leakage charge" that can be effected greatly by terminal condition.

Also make sure your terminals are clean. Dirty terminals are the cause of 99.44% of battery problems.

Bingo. I was just about to make the same 2 comments. If the results were reported in order, there is a problem that must be resolved before new batteries are considered.

 

[Prime Time]

More info

The terminals are all clean.
The charger is connected correctly to the bank.
I wish it were so simple!

Sorry to hear about the problem with some models of Charles Chargers. I looked at their web page and they do have a series of models. Mine appears more sophisticated than some with fusing of both AC and DC circuits and a 3 stage regulator.

 

[rpwillia]

Swear by nanopulsers

Has anyone used a nanopulser to rescue a sulfated battery?

On my last set my desulphinator circuit resuscitated the lead acid batteries and I got 3 more years out of them (e.g. one battery went from not starting the diesel to being able to do it anytime). Would not leave home without one.

 

[Prime Time]

what brand?

On my last set my desulphinator circuit resuscitated the lead acid batteries and I got 3 more years out of them (e.g. one battery went from not starting the diesel to being able to do it anytime). Would not leave home without one.

What brand and model did you have?

 

[chuckwayne]

Re: what brand?

We've had a nanopulser (thanks, SBO!) on our AGMs for 2 years, now and it definitely seems to have helped-no quantitative measurements but we certainly had better battery performance after adding it.