Yet Another Battery Woe

[shemandr]

I have some practical question for the group to help me sort out why my house bank isn't charging with the Freedom 20, Xantrex controlled charger.
It appears the bank voltage is very low because the engine won't start, the buzzer doesn't buzz and the instruments crap out when I press the starter button.
I recently changed the wiring of the batteries. I put my two old 4d's together into a house bank on "1" and the new 4d as a single spare on "2". It is the house bank which isn't charging. The Xantrex goes through the motions of charging (It cycles through the red, yellow and green -quickly) but the batteries don't improve. Several times prior to not charging the freedom was working hard on the battery bank as evidenced by the fan running continuously and an odor of hot wiring coming from somewhere. No overheat warning on the Xantrex. I think the batteries did charge, then.
I will be at the boat today and intend to verify that the 1 bank is the 1 bank on the battery selector switch.
If I disconnect the 2 battery (Newer single) and then turn on the selector switch to 2, I should not be able to measure any voltage on my panel voltmeter when its selected for 2 - right? That would confirm the 1 & 2 issue - right?
I also want to measure the voltage of each house bank battery while "Charged" and under no load. I intend to disconnect each from the battery wiring and test voltage at the batteries for each. What reading would indicate that they are not charged? Will one read so as to tell me its the bad one?
While the charger is on it indicates the voltage it is sending to the battery. Is it possible that the charger is not really sending that voltage to the battery? How can this be tested?
In the end I need to know if I have a bad battery, a bad charger or either a mis-wired house bank, or ill configured charger.

 

[Winkfish]

Sounds like you may well have a bad battery. Can you swap out your new battery to replace the house bank and see if it works? (Don't just wire it in parallel - disconnect your house batteries and sub the new battery in their place.)

 

[Don S/V ILLusion]

All you need to to identify the problem is measure the voltage at the batteries both when charging and when not. This will tell you definitively what the problem is - the charger or the batteries. This presumes you don't have a continuity problem in the wiring/ground which is also easy to identify with the same VOM.

 

[Stu Jackson]

Also check the water levels and use a hydrometer

 

[Webone]

Your Xantrex should show the voltage as 14+ if it is charging ok, otherwise the battery is not taking the charge and probably bad.

I have some practical question for the group to help me sort out why my house bank isn't charging with the Freedom 20, Xantrex controlled charger.
It appears the bank voltage is very low because the engine won't start, the buzzer doesn't buzz and the instruments crap out when I press the starter button.
I recently changed the wiring of the batteries. I put my two old 4d's together into a house bank on "1" and the new 4d as a single spare on "2". It is the house bank which isn't charging. The Xantrex goes through the motions of charging (It cycles through the red, yellow and green -quickly) but the batteries don't improve. Several times prior to not charging the freedom was working hard on the battery bank as evidenced by the fan running continuously and an odor of hot wiring coming from somewhere. No overheat warning on the Xantrex. I think the batteries did charge, then.
I will be at the boat today and intend to verify that the 1 bank is the 1 bank on the battery selector switch.
If I disconnect the 2 battery (Newer single) and then turn on the selector switch to 2, I should not be able to measure any voltage on my panel voltmeter when its selected for 2 - right? That would confirm the 1 & 2 issue - right?
I also want to measure the voltage of each house bank battery while "Charged" and under no load. I intend to disconnect each from the battery wiring and test voltage at the batteries for each. What reading would indicate that they are not charged? Will one read so as to tell me its the bad one?
While the charger is on it indicates the voltage it is sending to the battery. Is it possible that the charger is not really sending that voltage to the battery? How can this be tested?
In the end I need to know if I have a bad battery, a bad charger or either a mis-wired house bank, or ill configured charger.

 

[dave lundy]

I just went through a situation where the house battery showed 13.2 on the volt meter and all the cells tested A+ with the hydrometer. However, this battery would discharge within an hour or two using only the AP and GPS. I took it to a battery and auto-electric shop which also does loads of golf carts. They load tested it and it was junk.

So my advice would be to lug it to a shop which has some expertise in these things for a load test, then you'll know. Two batteries together in one bank can be the death of a good battery. If one is bad it will drive the charger crazy and kill the good one.

 

[seadaddler]

First

Get the batteries tested before going any further,not just rate of charge but test under load or test each cell.
I got a good battery tester a few years ago that test at flea market and should have borth more and sell them to boaters.
It is so great checking any kind of battery and than press the toggle
button for load test,it has saved me so much time and effort and from crazy screeming time.
My starting battery and one house bank went bad under warranty and this tested ended all the guess work right away,they were taking a charge but tested bad under load test.
Nick

 

[Winkfish]

Re: First

I just went through this last week on my Whaler. Battery seemed to charge up, but really did not. I could start the motor with my portable jumper (best investment I've made for the boat, by the way). I took the battery to Auto Zone, and they tested it for free - it was a bad battery.

 

[Stu Jackson]

So my advice would be to lug it to a shop...

Just another reason to get rid of 4D batteries and get something easier to handle.

 

[shemandr]

Thanks for your responses they are very helpful. The batteries are AGM's.
Amen Stu. Those puppies are going to kill me getting them to a shop. I may get the tester but as we've discussed there are testers and there are testers.
I spent some time with the volt meter today and these are the results:
The newer, solo "spare" battery tested 12.67 volts not connected to anything.
The two older batteries which were wired in series tested 12.54 volts separately and not connected to anything (Charge state is uncertain but Xantrex Charger indicated they were on float). While charging the newer battery tested 14.49 volts. The older bank batteries tested 12.54 not matter how I wired them and separately. It was at least ten trips from the depths of the lazarette to the panel and back - very sweaty
I took the covers off the Freedom 20 charger and tested the out put directly from the charger and it was 14.5 fluxuating some (That was a sweaty job due to the lack of room to remove the screws holding the plastic covers on).
Sounds to me like the charger is OK and the old battery(s) are bad. Now, which one or both.
I guess the best thing to do is buy a new 4d and put that and the newer one together as the house bank #1 and buy another starting battery for #2.
Right?

 

[Winkfish]

Andrew, will your new battery start the engine alone? If so, you might try hooking up the older batteries one at a time to try and start the engine. How old are the older batteries?

Also, are your sure they were wired in series? Wouldn't that supply 24 volts instead of 12? (Is that correct, Stu?)

 

[Stu Jackson]

Also, are your sure they were wired in series? Wouldn't that supply 24 volts instead of 12? (Is that correct, Stu?)

wink: yes, you're right.

I guess the best thing to do is buy a new 4d and put that and the newer one together as the house bank #1 and buy another starting battery for #2.
Right?

Andrew: Nope. If you're having trouble lugging them, a new 4D ain't gonna get any lighter. Sure, though, you do have choices: two group 31s would fit and give you a tad more amp hours, and then there's golf carts. Of course, more wiring, but what's the hernia worth to ya?

But only you know about the space conditions on your boat.

What I'm confused about is the going up and down to measure the voltage. Don't you have a DVM?

Looks like you're on the right track.

Don't know if your familiar with the primer, tech documents tab, for downloading at www.amplepower.com

 

[shemandr]

Space is not such a problem. It would be nice for new batteries to fit in the box for the two 4d's. I don't know what a group 31 is with regard to size, weight or amp hours. Something I have to look at. I do have the one good AGM 4d which I am not ready to throw away.
I have no intention of carrying those bad batteries off the boat. I do not want a hernia or blown back disk. I will hire someone, who is insured for injury. Its the only sane way to do it.
DVM = digital volt meter? I have a portable one. I am a big chicken so everything has to be off before I change anything with the wiring at the battery. Hence the trips up and down. The boat panel has a volt meter but I don't understand where it measures voltage from and I don't trust its accuracy or wiring. If I learned anything today it was you have to measure voltages at the battery.
I am not familiar with that link but will check it out. Thank you.

 

[Stu Jackson]

Again, on the right track. While you're at it, start drawing a wiring diagram.

I don't know what a group 31 is with regard to size, weight or amp hours.

Go look it up on the West Marine website, or Defender. C'mon...

Keep us posted.

 

[Bill Roosa]

Have you ever tested the batteries

Sounds like most folks on this post do not know how to test a battery with a volt meter. This is a basic skill that I think ALL sailors should have. you will not have Auto Zone at sea.
First, stop doing everything, turn off everything that is a load or is charging the batteries. Turn the 3 way to off. Wait around an hour.
Take out your multi meter and measure the voltage on each battery by putting the multimeter probes to the battery terminals. Write down what you get. Wait another hour and remeasure. Write this down and call it "rest voltage"
Good batteries should show normal voltage in both tests. Bad batteries will show reduced and falling voltages.
Set the 3 way to bank 1 and turn on the charger. The voltage should increase to normal charge voltage. Set the 3-way to bank 2. the voltage should also increase. A good battery charger will show an increased voltage on a good battery or a bad battery.
Turn the 3-way back to bank 1 and charge the battery for 15 minutes. Turn the 3-way to bank 2 and charge for 15 minutes. Turn off the battery charger. A good battery will show a slight increase in voltage (after 15 minutes of resting) over the the rest voltage a bad battery will show no or a reduced voltage.
By consistently monitoring the battery voltage(panel voltage) you will be able to detect a battery going bad well before it becomes a problem.

 

[Stu Jackson]

Hey, Bill, just to yank your chain: there are four positions: one is OFF.

And some switches have different orders: 1 B 2 O, 12BO, O1B2, etc.

Good description of how to.

 

[Maine Sail]

Turn the 3 way to off. Wait around an hour.
Take out your multi meter and measure the voltage on each battery by putting the multimeter probes to the battery terminals. Write down what you get. Wait another hour and remeasure. Write this down and call it "rest voltage"
Good batteries should show normal voltage in both tests. Bad batteries will show reduced and falling voltages.

Even good batteries can continue to lose voltage over 2 - 24 hours, before becoming stable, while resting. Spent a lot of time on the bench measuring a way to accurately determine "resting voltage" with a known good battery or bank. Tried resting it, and applying varying "loads" to see if a 24 hour rest agreed with the "loads" I applied to remove the surface charge. Even at 4 hours resting my battery showed it was still off by roughly 15% compared to the reading after a 24 hour rest. A 15% variance on a 400 Ah bank is 60 Ah's, or a full day of cruising for many boaters.

At two hours they are usually not at an accurate "rest" yet and the voltage is usually still falling. The idea that a only the "bad" battery will be showing a dropping voltage at two hours is not really an accurate way of testing IMO based on taking accurate measurements over time.

Measuring A Lead Acid Battery Resting Voltage (LINK)

I think you can easily rest the batts and measure over a period of time the differences in resting voltage. If both batteries are good or in equal condition, which they ideally should be having been the same "bank" for a long while, the the resting voltage should be dropping at nearly an identical rate. Of course, a load tester brought to the vessel is far easier than moving the 4D's to the battery tester.

It is not really advisable to replace one new battery and combine it with an old battery. Usually when one batt goes bad in a bank you replace the entire bank as batteries deteriorate over time. Unless you can confirm, with a very expensive battery tester such as the Midtronics EXP-800, the condition or the remaining battery, I would not risk mixing old with new.

Some batteries attain "rest" faster than others. The only way I have found to accurately know "rest" is to wait. If you test at 4, 12, 24 you'll likely still see dropping voltage until the batts finally level off and the 24 hour can be compared to 36, 40 48 and you'll see little to no movement in the reading.

I recently changed the wiring of the batteries. I put my two old 4d's together into a house bank on "1" and the new 4d as a single spare on "2". It is the house bank which isn't charging.

This could have been the root of the problem. Even though they were on the same boat, and may have been installed at the same time, they were likely cycled differently. Both batts likely had differing cycle life spans. With each cycle/discharge batteries lose life. If one battery had less cycles and was combined with one that had considerably more they don't tend to like that. It could just be age too and they are just done..

 

[bobtigar]

group 31 is a 27 on steroids-105 amps. Slightly larger than a 27 Bob

 

[LloydB]

what is your load voltage measured at the engine,and at the battery when starting? thanks wink at reply#8 btw you might want build some really long custom made test leads but be aware that long leads affect accuracy of some measurements

 

[Maine Sail]

group 31 is a 27 on steroids-105 amps. Slightly larger than a 27 Bob

Depending upon brand they can range as high as 130 Ah each at the 20 hour rate.

The Trojan SCS-225 is 130 Ah Dimensions = 13 15/16" Long - 6 3/4" Wide - 9 7/8" Tall (this battery is about 1" longer than the standard group 31)

The WM/Deka group 31 is 105 Ah at the 20 hour rate. 13" Long - 6 3/4" Wide - 9 1/2" Tall

The US Battery group 31 model, US31DCXC is also 130 Ah at the 20 hour rate. It, like the Deka, is a standard grp 31 case @ 13" Long - 6 3/4" Wide - 9 1/2" Tall.

The Wal*Mart Maxx 29/31, made by Johnson Controls, is also 130 Ah at the 20 hour rate. It is 12 7/8" Long - 6 3/4" Wide - 9 1/2" Tall.