Mysterious battery drain... where to begin?

[ramblinrod]

Originally Posted by OrangeCrush

Hello,

My new-to-me boat is hauled out for the winter and it seems that the house battery is draining on its own somehow. The battery monitor shows zero amps of draw when the house switch is turned off, but after two weeks or so the voltage drops from 12.8 to 12.0 or lower. The only thing I know that is hard wired is the bilge pumps which are both off.

The previous owner said that the batteries would hold a charge through the winter without being disconnected. In general the wiring is in good shape and most of it was redone 3 years ago. The batteries are 4 AGMs for 440 amp hours total. I'm sure it's not good for them to get so low, but a month ago when I was sailing they were able to maintain their charge through pretty heavy usage over the course of a weekend, so I don't think they're shot (yet). The starter battery is charged with an echo charger and is staying full. The only switch I've been leaving on while the boat is unplugged is the Main AC double breaker because the PO said he never turned it off. Could that be a factor? The battery monitor itself seems to stay on but I can't imagine that draws much nor do I know how to turn it off.

I've got a multimeter and I'm ready to crawl into whatever nook I need to crawl into, but I don't know where to start. If the battery monitor shows zero draw, I don't see how pulling fuses or disconnecting wires will help me find the source of the draw.

Here is a picture of my panels (while on shore power) Any advice is most Attachment 136469greatly appreciated!


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Back to the original post.

Two possibilities:

a) There is an unexpected connected load. Use a DVM to start isolating potential load circuits, until the unexpected load is discovered.

b) The batteries aren't holding a charge. Perform a load test.

(While the battery monitor represents a load, and I would isolate that first, it alone should not discharge the batteries as rapidly as you are experiencing.)

It could be an incandescent light, perhaps not easily seen under normal circumstances. Check the engine compartment.

[OrangeCrush]

Originally Posted by ramblinrod

Back to the original post.



Two possibilities:



a) There is an unexpected connected load. Use a DVM to start isolating potential load circuits, until the unexpected load is discovered.



b) The batteries aren't holding a charge. Perform a load test.

a) There is a load, but it is only a fluctuating load of 23-33mA as per the disconnected positive terminal ammeter test, which is not nearly enough to drain my 440ah bank in less than a week.

b) On it, as Jim said I've got enough to keep me scurrying. I disconnected the batteries and they all measured 12.9v after sitting for one hour. I ordered a cheap Schumacher load tester. Next week I will see how the voltage has dropped over time and if it drops suddenly with a load.

c) There is this third possibility as well that the batteries are not getting charged up fully in the first place. Seems less likely since the batteries were crapping out regardless of whether they were charged by alternator or shore power. Then again, I did find that loose ground on my regulator and I do have the Xantrex setup that suffers from the "gotcha" problem described earlier in the thread.

About the Xantrex issue, the one thing I don't understand (forgive me if this is a dumb question) is how the battery monitor itself affects the battery charge process. I thought that the Freedom 20 charger would control this while on shore power and Balmar regulator would do so while motoring. How do the Link 10 settings effect the way the battery is being charged? Regardless I will try changing the settings and seeing if it makes a difference, but I don't really understand how they affect each other.

Thanks!


Sent from my iPhone using Cruisers Sailing Forum

[ramblinrod]

Responses in red.

Originally Posted by OrangeCrush

a) There is a load, but it is only a fluctuating load of 23-33mA as per the disconnected positive terminal ammeter test, which is not nearly enough to drain my 440ah bank in less than a week.

Correct, if your battery bank was fully charged, and in good working condition. It should take almost a 1A load two weeks, to drain your batteries from fully charged to 50% charged.

b) On it, as Jim said I've got enough to keep me scurrying. I disconnected the batteries and they all measured 12.9v after sitting for one hour. I ordered a cheap Schumacher load tester. Next week I will see how the voltage has dropped over time and if it drops suddenly with a load.

It is better to take the "at rest" measurement after 12 hours of self discharge, or as simulated after 15 minutes of 5% capacity load. In your case (440 A-hr cap.), right after coming off the charger, with a 20A load applied for 15 minutes, your batteries should read 12.8V dc (with no residual charge voltage present).

c) There is this third possibility as well that the batteries are not getting charged up fully in the first place. Seems less likely since the batteries were crapping out regardless of whether they were charged by alternator or shore power. Then again, I did find that loose ground on my regulator and I do have the Xantrex setup that suffers from the "gotcha" problem described earlier in the thread.

Well, if you measure 12.8Vdc at rest (as described), they are fully charged, regardless what the battery monitor indicates.

About the Xantrex issue, the one thing I don't understand (forgive me if this is a dumb question) is how the battery monitor itself affects the battery charge process. I thought that the Freedom 20 charger would control this while on shore power and Balmar regulator would do so while motoring. How do the Link 10 settings effect the way the battery is being charged? Regardless I will try changing the settings and seeing if it makes a difference, but I don't really understand how they affect each other.

Thanks!


Sent from my iPhone using Cruisers Sailing Forum

When one is charging by alternator, if the battery monitor erroneously indicates full charge (when in fact they are only partially charged) and the engine is shutdown, then it is the user intervention (based on the erroneous battery monitor indication) that is preventing batteries from being fully charged (assuming no other charge source, like shore, solar, or wind, to continue bringing the batteries to true full charge.

[mitiempo]

Originally Posted by OrangeCrush

About the Xantrex issue, the one thing I don't understand (forgive me if this is a dumb question) is how the battery monitor itself affects the battery charge process. I thought that the Freedom 20 charger would control this while on shore power and Balmar regulator would do so while motoring. How do the Link 10 settings effect the way the battery is being charged? Regardless I will try changing the settings and seeing if it makes a difference, but I don't really understand how they affect each other.

The battery monitor has zero effect on battery charging. Look at it like a fuel gauge (albeit more complicated) - it tells you what is in the tank but has no control over how much is in the tank.

[OrangeCrush]

it is the user intervention (based on the erroneous battery monitor indication) that is preventing batteries from being fully charged [/QUOTE]

This was my initial understanding, but I'm confused by this line (and another like it) in the conversation Stu linked: I have changed these parameters on our Link and the results have been fantastic and exactly as Rich described. Before, our Freedom 15 Inverter/charger combo, after a daysail, would go from bulk to absorption to float within ten minutes of being plugged in. After the change to the parameters, the charger stays on absorption for a much longer time. Ron Hill's comment, below, is also another way to check if you do the charger controls manually. Since our Link controls the charger, it is necessary for our use.

[mitiempo]

Originally Posted by OrangeCrush

it is the user intervention (based on the erroneous battery monitor indication) that is preventing batteries from being fully charged

This was my initial understanding, but I'm confused by this line (and another like it) in the conversation Stu linked: I have changed these parameters on our Link and the results have been fantastic and exactly as Rich described. Before, our Freedom 15 Inverter/charger combo, after a daysail, would go from bulk to absorption to float within ten minutes of being plugged in. After the change to the parameters, the charger stays on absorption for a much longer time. Ron Hill's comment, below, is also another way to check if you do the charger controls manually. Since our Link controls the charger, it is necessary for our use.
[/QUOTE]

Stu has a different monitor - Link 2000 as I recall. Very different from a simple Link 10.

[OrangeCrush]

Originally Posted by mitiempo

Stu has a different monitor - Link 2000 as I recall. Very different from a simple Link 10.

Ah ok. Yeah I was confused by the implication that the battery monitor was affecting my charging (except if I stop charging early because of misinformation).

[Stu Jackson]

Originally Posted by OrangeCrush

Ah ok. Yeah I was confused by the implication that the battery monitor was affecting my charging (except if I stop charging early because of misinformation).

Yes, a Link 2000 is different than a Link 10. BUT: they use the same algorithm.

That's the whole point.

[Stu Jackson]

Originally Posted by OrangeCrush

My question is: if my boat is configured for AGMs right now with a Xantrex Freedom Inverter/Charger Model 20, Balmar Max Charge Regulator, and two Balmar Alternators, then what changes (if any) would I need to make to convert the boat to properly maintain a flooded lead acid house bank?

Simple.

Freedom 20: you'll need to change the dip switch settings on your remote panel, if you have one. Your Link 10 doesn't control the F20, IIRC. My Link 2000 controls my F15.

Balmar Max Charge Regulator (most likely an MC-612, or maybe a newer MC-614) You'll need to reprogram to FLA voltages. There are the presets in the manual.

If you don't have the manuals, they are available online for the Freedom (Xantrex's discontinued models), and at www.balmar.net

[OrangeCrush]

Originally Posted by Stu Jackson

Yes, a Link 2000 is different than a Link 10. BUT: they use the same algorithm.

That's the whole point.

I will definitely take that into consideration and adjust the settings accordingly when I get my batteries working properly again, but since the Link 10 doesn't actually control the charger I don't think that's the culprit at this point.

[OrangeCrush]

Originally Posted by Stu Jackson

Simple.

Freedom 20: you'll need to change the dip switch settings on your remote panel, if you have one. Your Link 10 doesn't control the F20, IIRC. My Link 2000 controls my F15.

Balmar Max Charge Regulator (most likely an MC-612, or maybe a newer MC-614) You'll need to reprogram to FLA voltages. There are the presets in the manual.

If you don't have the manuals, they are available online for the Freedom (Xantrex's discontinued models), and at www.balmar.net

This is very helpful, thanks! Yes I've been going through the manuals...

Do you agree with the choice of a FLA bank for the purposes I described? (At a mooring then full-time cruising, 2 alternators and 200w solar with very little or no time on shore power)

[mitiempo]

Originally Posted by OrangeCrush

Do you agree with the choice of a FLA bank for the purposes I described? (At a mooring then full-time cruising, 2 alternators and 200w solar with very little or no time on shore power)

I certainly do.

[DewTheDewDude]

Hit your solenoids with a hammer in case they are stuck open

[Stu Jackson]

Originally Posted by OrangeCrush

This is very helpful, thanks! Yes I've been going through the manuals...

Do you agree with the choice of a FLA bank for the purposes I described? (At a mooring then full-time cruising, 2 alternators and 200w solar with very little or no time on shore power)

I agree with mitiempo. Makes good sense.

Look, for the past 40 or 50 years they've come up with new and in most cases, better battery technology.

However, now that you understand the advantages and disadvantages of each kind of battery, it makes life a lot easier.

But nothing much has changed for us recreational boaters if you're comparing FLA, gel and AGMs in the past 20 years.

There is a parallel thread ongoing in the electrical section about the best bang for the buck on batteries and life expectancy re depth of discharge. You might want to read that entertaining thread, too.

[Cadence]

How did it get to rocket science to trace a bleed or just shot batteries?