Defective Onboard charger

[scokill]

So I bought a 2 bank onboard charger last year and it was great...just plug in when finished and the batteries are always charged. So I left it plugged in this fall and winter to keep up the batteries...even check on it a couple of times during the winter. So I go out to the boat and both batteries are dead as a doornail. Evidently the charger has crapped out as the error lights are blinking. All fuses good and it's not humming as it usually does. I hooked up my old charger and it initially showed 0 volts but the deep cycle is taking a charge. I have a feeling I will be taking both to sears as they are under replacement warranty.

 

[David Analog]

11.8 volts is about as low as you should ever allow a deep cycle battery to discharge during usage. Certainly much less for a starting type battery.
The batteries didn't self-discharge down to 5 or 6 volts in a matter of months, let alone any lower, without there being a specific problem, whether it is a bad charger, a continuous load or a bad battery.
If the batteries get too low and fall below a given voltage threshold, a moderate charger will naturally go into protection mode and will be idle until you bring the batteries up to a serviceable charge level. That might be 10 volts? The point being, is that the charger may or may not be defective. You can't make that assessment with the present battery(s) status.
The larger question is how did two isolated battery banks on a dual bank charger BOTH go dead?

 

[scokill]

11.8 volts is about as low as you should ever allow a deep cycle battery to discharge during usage. Certainly much less for a starting type battery.
The batteries didn't self-discharge down to 5 or 6 volts in a matter of months, let alone any lower, without there being a specific problem, whether it is a bad charger, a continuous load or a bad battery.
If the batteries get too low and fall below a given voltage threshold, a moderate charger will naturally go into protection mode and will be idle until you bring the batteries up to a serviceable charge level. That might be 10 volts? The point being, is that the charger may or may not be defective. You can't make that assessment with the present battery(s) status.
The larger question is how did two isolated battery banks on a dual bank charger BOTH go dead?

I get it...we'll see when/if they get back up to charge and hold I'll see if charger works.. They are still under warranty and if there is an issue they will get replaced.

 

[Island Jay]

What is the make/model of the charger?

 

[Glassman]

11.8 volts is about as low as you should ever allow a deep cycle battery to discharge during usage. Certainly much less for a starting type battery.
The batteries didn't self-discharge down to 5 or 6 volts in a matter of months, let alone any lower, without there being a specific problem, whether it is a bad charger, a continuous load or a bad battery.
If the batteries get too low and fall below a given voltage threshold, a moderate charger will naturally go into protection mode and will be idle until you bring the batteries up to a serviceable charge level. That might be 10 volts? The point being, is that the charger may or may not be defective. You can't make that assessment with the present battery(s) status.
The larger question is how did two isolated battery banks on a dual bank charger BOTH go dead?

Good question!
Any chance power to the charger was off for an extended time between the last time you checked and now? Batteries died and now, even with power present they won't take a charge. just thinking out loud...

 

[David Analog]

Winter storms combined with marina boat houses (if that's the case) are often a bad mix. But on the other hand, with a small boat up on a slip, no active bilge pump, and no refrig, etc, etc, and given that batteries only self-discharge a few percent per month, the question remains how did good batteries go down that fast?

 

[Julian]

Was anything in the boat still hooked up and running or were the batteries out of the boat?

 

[Island Jay]

My brother in law purchased a brand new 50k Chaparral wakeboarding boat a few years back. His batteries were always dead within a few days from day one. Dealer could not figure it out and chalked it up to something on board.

Just like your TV, DVD player, Cable Box, PC, etc.... even when off they STILL draw power. If the devices on your boat are still drawing power ( Radio, GPS, fish finder, etc etc ) they can and will drain your battery. If the are not power smart, they will do it over the weekend.

 

[txav8r]

I also want to know what the make and model of the charger is @scokill , if it didn't drop off line and allow the batteries to go below threshold, then I would be checking that charger. If it is a smart charger, you can certainly leave them plugged in all the time without fear. If it isn't a smart charger, it is a bad thing to leave them plugged in.

Totally agree with you @ChargerGuy , there has been a history on some models of Yamahas that tend to have incideous drains on the battery(s). And the easy solution has been to put in a battery switch and kill all battery drains.

 

[Glassman]

With an acknowledgement to all of the above, I must say that I've experienced a similar situation with a charger from time to time.

Example: I hook up a maintainer to a battery that I know to be good. It will have at least an 80-90% charge and I just want to bring it up and maintain it. The charger is a smart charger, it goes through the steps, does the bulk charge stage and then all of a sudden it starts flashing as though there was a problem with the battery and it doesn't charge.

What causes that?

After I disconnect and connect again it appears to charge just fine. The battery wasn't hot prior to connecting, nothing else going on that I can think of.

 

[Island Jay]

Could be...
1. bad charger
2. bad ac/dc fuses
3. bad install/non matching voltages
4. not enough ac power/semi tripped breaker
5. bad battery.

 

[Zarrella]

6. Operator error!....LOL

 

[Glassman]

Or, unfortunately, none of the above. I'll chalk it up to Gremlins...since all the batteries I've subsequently used that charger on have reached full charge and maintained a charge, I don't think it's the charger.
No fuses are blown or breakers tripped.
All 12v involved - batteries and charger.
power is fine
battery is fine, checked with hydrometer and load tester - and it's only about 9 months old (yes I realize it could have died within that time....but it still cranks fine)

No worries, I'll just keep plugging along. But the point I was trying to make is that sometimes things happen. Sometimes a charger can act strangely...at least around me.
So, operator error is always a possibility.

I get pebkac errors here at the office all the time.

 

[davel501]

Or, unfortunately, none of the above. I'll chalk it up to Gremlins...since all the batteries I've subsequently used that charger on have reached full charge and maintained a charge, I don't think it's the charger.
No fuses are blown or breakers tripped.
All 12v involved - batteries and charger.
power is fine
battery is fine, checked with hydrometer and load tester - and it's only about 9 months old (yes I realize it could have died within that time....but it still cranks fine)

No worries, I'll just keep plugging along. But the point I was trying to make is that sometimes things happen. Sometimes a charger can act strangely...at least around me.
So, operator error is always a possibility.

I get pebkac errors here at the office all the time.

The troubleshooting steps for the battery tender that I use for my waverunner actually says to disconnect everything and try again when it detects a bad battery. Must be the charger equivalent of rebooting.

 

[Glassman]

The troubleshooting steps for the battery tender that I use for my waverunner actually says to disconnect everything and try again when it detects a bad battery. Must be the charger equivalent of rebooting.

EXACTLY!
With no one around to disconnect and re-connect, the charger just sat there blinking.
Maybe they should make a Wi-Fi enabled charger that will send an email when there is a problem. I have email enabled cameras equipped with motion detectors all over my factory. They send emails when they detect anything.

 

[davel501]

EXACTLY!
With no one around to disconnect and re-connect, the charger just sat there blinking.
Maybe they should make a Wi-Fi enabled charger that will send an email when there is a problem. I have email enabled cameras equipped with motion detectors all over my factory. They send emails when they detect anything.

Too bad it's not just unplug and plug back in. One of those 7 day timers could reset it weekly. Might be easier to just disconnect the batteries and let them sit for the winter.

 

[txav8r]

@Glassman , the conversations I have had with PulseTech indicate to me, that smart chargers are built so sophisticated, that if anything gets out of tolerance, it takes itself out of the loop. The AGM batteries I had monitored on the dawg by a dual X2 charger, would show one or both batteries at only 75% occasionally continuously. The told me that while they try to make everything so user friendly, that the last charge indicator light is from 75-99% and that it has to be 100% to light the 100% light. That bothered me, because it could be 76% too! But the chargers are incredible the way they warm up a battery, test it, then start to turn up the juice, and then back off when it reaches 75-80% charged, and bring it up slowly to 100%, then only monitor and maintain as needed. Changed the way the world charges batteries!

 

[scokill]

I know you've all been on the edge of your seat....one bad battery, one good battery. Evidently charger went into error state for the one bad battery and the other just discharged over time. Sears replaced my big platinum deep cycle for free.