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-   -   Troubleshooting Drained batteries and Dead Charger. (https://www.cruisersforum.com/forums/f14/troubleshooting-drained-batteries-and-dead-charger-226232.html)

Santiano 07-11-2019 20:52

Troubleshooting Drained batteries and Dead Charger.
 
Hey all,

I'm just beginning to learn about electrical systems, and would appreciate any pointers yous can give.

I'm connected to shore power at a marina, have a ProSport 6 amp battery charger, and a 12-volt house bank. I have not gotten around to installing a separate starter battery, which I am now regretting. That's a project that will have to happen soon.

I arrived at the boat this evening to find that lights were dim and the fresh water pump was barely turning over. I went to the batteries to check for loose connections and found a negative terminal sparking where the charger was connected. Without turning the charger off, I rearranged and tightened the connection to the negative terminal. The terminal sparked as I did so, and the charger light went from "batteries full" to dead. No lights.

Where on Earth do I start the diagnostic? I cannot find any trip or reset on the charger. It plugs into an AC outlet and runs off the shore power. My outlets connect directly to the AC shore power, and still work fine, but all the built-in DC electronics are nearly dead.

I heartily appreciate any direction you can give me.

Cheers,

Santiano.

rbk 07-11-2019 21:00

Re: Troubleshooting Drained batteries and Dead Charger.
 
Put a multimeter on the battery at the posts and see if thereís a difference. Follow the cable/wire and check for corrosion and breaks on both red and black lines.

billknny 07-11-2019 21:11

Re: Troubleshooting Drained batteries and Dead Charger.
 
If you have flooded batteries, sparking at the terminals can lead to ignition of the hydrogen offgass. That can be a VERY nasty result. I know of several boats that has happened to. Sparks around FLA batteries are potentially very dangerous.

Santiano 07-11-2019 21:24

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by billknny (Post 3011505)
If you have flooded batteries, sparking at the terminals can lead to ignition of the hydrogen offgass. That can be a VERY nasty result. I know of several boats that has happened to. Sparks around FLA batteries are potentially very dangerous.

I've looked for some indication of whether they're Flooded AGM or Gel, or what. All it says is "Marine Deepcycle." How do I determine the type?

smac999 07-11-2019 21:50

Re: Troubleshooting Drained batteries and Dead Charger.
 
A 6 a charger is way to small to keep a battery charged while on the boat.

NYSail 07-11-2019 23:01

Re: Troubleshooting Drained batteries and Dead Charger.
 
If your battery has caps that can be opened they are flooded. Check water level...... should be about 1/4 inch above plates inside battery. Only use distilled water. If no caps on battery they are agm (sealed) and don’t need servicing.

Good luck!

GordMay 08-11-2019 05:03

Re: Troubleshooting Drained batteries and Dead Charger.
 
Greetings and welcome aboard the CF, Santiano.

Sailmonkey 08-11-2019 05:27

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by smac999 (Post 3011518)
A 6 a charger is way to small to keep a battery charged while on the boat.



We used one for years with a 440Ah bank.

True, its too small to maintain the batteries when theyíre in use, but for a week at the dock, itíll do the trick.

That said, we found that if the charger was left on while the refrigerator was running the battery voltage would climb to extremely high levels and stay there. These little chargers are only intended to charge a battery that is not in use.

noelex 77 08-11-2019 06:03

Re: Troubleshooting Drained batteries and Dead Charger.
 
Welcome to the forum Santiano.

From your description I suspect the negative terminal of the battery charger had a poor connection and so the batteries drained to a very low state of charge.

Many smart chargers will not start charging a battery that has very low voltage. They do not recognise a battery is connected if the voltage is below a certain level.

If you can borrow another charger, preferably one of the old dumb chargers this will sart to charge even a very low battery. After a short time the voltage is likely to have risen to level where your smart charger will start working again.

A 6 amp charger is small but providing your electrical needs are modest it should manage fine. 6amps over 24 hours is 144 Ahrs. Many battery chargers will not supply their rated capacity continuously and there are some conversion inefficiencies, so you might have a little less than this, but providing you are not using more than around 120AHrs a day the battery should slowly charge.

Having drained the battery bank this low the batteries may have a permanent and significant loss of capacity, so make sure you fit that starter battery.

sailing_gal 08-11-2019 10:23

Re: Troubleshooting Drained batteries and Dead Charger.
 
After having drained your batteries so low, you may need to equalize them to get back the capacity. Check with your battery manufacturer to see at what voltage and for how long to charge them.

TrentePieds 08-11-2019 10:41

Re: Troubleshooting Drained batteries and Dead Charger.
 
Hello Santiano and welcome :-)

You have some valuable replies up above, but since you profess to being a newbie with no particular knowledge of electrics, let me go right back to basics and tell you how I would approach your problem:

1) You haven't said what kind of boat you have, how big it is and whether you sail for short periods ( a few days, a week or two) out of a marina, or whether you need to be independent of the shore for long periods. Those things affect the complexity your electrical installation, but fortunately you can start very simple and "build up" as your experience and your need for independence grows.

So for a boat up to sort-of-36-foot-ish sailed by a newbie, batteries of the kind you have will be sufficient. Two 27-series "Marine Deep Discharge" batteries are not ideal but they are GOOD ENUFF, provided you treat them with respect. And that's IMO what counts. That's what I use in a 30 footer, and I consider them disposable, so they get changed [not charged but changed :-)] every 4 years. My 20 HP Beta (Kubota) takes so little juice to start that there is no need for a separate starter battery at all.

Good battery management starts with ensuring that ALL your electrical connections throughout the boat are clean and tight. If your boat is new to you, then trace all through its wiring and verify the integrity of all the connections and terminals. If you do that conscientiously you won't have to look at them again as long as you own the boat, and you will have a very clear picture, either in your mind, or as I prefer, on paper.

Now we can look at your battery setup. The reason that the wires twixt your main switch (presumably a "1 - 2-both - off" switch) and the batteries, and between the switch and the engine, are fat is that they have to carry a LOT of juice. And because they carry a LOT of juice, loose terminals will corrode and build up resistance to the flow of current VERY fast. So clean these terminals inside and out, making sure that when you assemble them again they are as sailors say, "***** and briney" :-)

You spoke of sparks on the negative terminal. That bespeaks current flowing, i.e. SOME device in the boat was "on" when you disconnected the terminal, or there is a short circuit somewhere in the system. Ensure that 1-2-B-0 switch is off, but leave your "housekeeping" main switch "on", if you have one. Then disconnect the N-terminal again. If it sparks again, you have a short in the system. That's a crude initial way of doing diagnostics. In a future post we can deal with more sophisticated ways of doing these things if necessary.

Batteries are, as you already know, analogous to a savings account at the bank. If you put in as much juice as you take out in any given period of time, you are in clover. If you take out more than you put in you are headed for perdition. Therefore ALWAYS arrange matters so that you CAN put in more than you have to.

This brings us to the matter of an Energy Budget. Such a budget will tell you how much juice you will be taking OUT of the batteries in the normal course of your being aboard, and therefore it tells you also the reciprocal: The MINIMUM you should be able to put back into the batts. Come back to us if you need help with that :-)

And that brings us to the charger that takes its current from the plug-in point on the dock at your marina. Intuitively I think what you have is barely sufficient, but there again, do think about all the things that are in this thread, then we can come back to taking about a suitable charger for your batteries and your circumstances,

All the best

TrentePieds

OS2Dude 08-11-2019 11:26

Re: Troubleshooting Drained batteries and Dead Charger.
 
We had a ProMarine ProSport 20 charger. I came to the boat one day to find the batteries DEAD. All lights but power where out on the charger. Replaced the batteries. (2 98ah AGMs, about $700 to replace) Called PorMarine, they sent me a new plug that tells it what type of battery it is attached to. Came up another time to find the batteries almost dead, but was able to get the engine started and charged the batteries that way. Again, all lights were out except power. Called ProMarine a second time, they told me there was a flaw in the design that allowed the LED that 'reads' the plug to move, and if the unit can't tell what the plug says, it stops charging all together. No alarm light, no buzzer, just NOTHING. They offered to replace the entire charger, but could not guarantee the new unit would not have the same issue. Said there was no way to tell when the 'fix' was implemented... Huh? Since I bought it from West Marine with an extended warranty, I just returned it. Bought two 100V solar panels and controller and have had no issues since.

hamburking 08-11-2019 11:29

Re: Troubleshooting Drained batteries and Dead Charger.
 
2 Attachment(s)
Quote:

Originally Posted by smac999 (Post 3011518)
A 6 a charger is way to small to keep a battery charged while on the boat.

I disagree. It would be too small if there is refrigeration. But with LED lights, and not leaving the dock, it should be fine.

But is it a smart charger?

I would start by unplugging (or switching off) shore power (to power off the charger). Then check the water level in the batteries. My experience is that people who don't know anything about batteries tend to have them empty (or very low). Fill as needed with distilled water. Then plug in again and see what the charger does.

Time to get a digital voltmeter!

FWIW, I use a simple/cheap device (bought on ebay for like $3). Its a digital voltmeter that plugs into a 12 volt (cigar type) outlet and constantly shows voltage. It is a wonderful tool that allows you to constantly monitor your batteries. Knowing your batteries (and system) is half the battle.

Many chargers have a current indicator. Thats important info too.

And finally, be sure its a MARINE charger. One feature of a MARINE charger is that it does not put a load on the batteries when not in use. (some/most) AUTOmotive chargers will put a load on the batteries when not in use, and drain them pretty efficiently.

a64pilot 08-11-2019 11:39

Troubleshooting Drained batteries and Dead Charger.
 
Iím going to bet that the batteries are dead, and he was essentially running off of the charger, then fried the charger, and is now on dead batteries.

In my opinion even a 20 amp charger is too small, and Iíd even go so far as to say that since batteries set the rate at which they will accept a charge, you canít have too big a charger, and that often charging at the highest rate that a battery will accept is good for the bank, it shortens the time a battery has to sulphate and on flooded batteries has a tendency to stir the electrolyte keeping it well mixed up, because stratification is an issue for flooded batteries, more so on big tall batteries of course but itís there even on golf cart batteries.

However as I suspect you will be buying a battery charger, be sure to buy one that you can set the absorption and float voltages yourself to the .1V, donít buy one that has settings for Gel, AGM and flooded, because they may or may not be close to correct as many different batteries of the same type have different voltages, so one setting canít work for all of them.

Santiano 11-11-2019 15:20

Re: Troubleshooting Drained batteries and Dead Charger.
 
Thanks to everyone who replied!
I bought a cheap automotive 2-amp trickle charger as an emergency device to stop my house bank from losing its ability to hold a charge. I disconnected the two older batteries, and have charged them up to hopefully use as an emergency bank. The two new batteries are charged and running nicely, although I'm careful to use very little power because of the tiny charger.

I'll be ordering about 200watts worth of solar panels, along with a charge controller, by next weekend. The current plan is to rely on solar for the foreseeable future. I'm in a slip for the most part right now, but will be leaving to begin cruising within a year.
I learned a good number of details from yous all, and a few contradictory bits that I'll have to work out for myself!
Cheers, and thanks again!

rbk 11-11-2019 15:55

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by Santiano (Post 3013981)
Thanks to everyone who replied!
I bought a cheap automotive 2-amp trickle charger as an emergency device to stop my house bank from losing its ability to hold a charge. I disconnected the two older batteries, and have charged them up to hopefully use as an emergency bank. The two new batteries are charged and running nicely, although I'm careful to use very little power because of the tiny charger.

I'll be ordering about 200watts worth of solar panels, along with a charge controller, by next weekend. The current plan is to rely on solar for the foreseeable future. I'm in a slip for the most part right now, but will be leaving to begin cruising within a year.
I learned a good number of details from yous all, and a few contradictory bits that I'll have to work out for myself!
Cheers, and thanks again!

Read the article under ďNo,no,no, no!!!!!!!!!Ē :facepalm:
https://marinehowto.com/installing-a...ttery-charger/

Santiano 11-11-2019 16:03

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by rbk (Post 3014010)
Read the article under ďNo,no,no, no!!!!!!!!!Ē :facepalm:
https://marinehowto.com/installing-a...ttery-charger/

Jaysus, I can't get anything right!

Fair enough, I guess I'll unplug the damned thing and just not use my batteries until the PV panels arrive.

Would it be that hazardous to use the car charger for just a week, though?

rbk 11-11-2019 16:19

Re: Troubleshooting Drained batteries and Dead Charger.
 
You really need to purchase a proper shore charger to properly charge and maintain them for a bit; right after you determine if theyíre shot. Buy a multimeter and figure out why they went dead in the first place I.e. find the power draw that killed the bank, which may be something wired direct to the bank or a short somewhere. If thereís a short the auto charger can make the situation worse. Spend the time and read Trentís advice in this thread, read rest of the articles in the link I provided and save yourself money and time. Not trying to be critical but you shouldnít just try and throw more power (solar) at it until you know where your power is going.

Boatpokers website has good examples of why you should be trying to track this down, read thoroughly:
Marine Surveyor, Port Credit Marine Surveys, Toronto, Ontario

TrentePieds 11-11-2019 18:04

Re: Troubleshooting Drained batteries and Dead Charger.
 
Santiano:

I cannot endorse strongly enuff what rbk has told you. Don't press ahead too fast - listen to your elders ;-)! You can spend a lot of money to no effect by not being careful about how you treat your batteries and your electrics generally.

Get you head around the time it takes to charge a battery using ANY kind of charger. Getting impatient and "forcing" the charge is VERY costly in terms of battery damage. That is why I mentioned the matter of a "power budget" and the desirability of tracing your entire installation to makes sure there are no short circuits anywhere.

None of this stuff is difficult to get you head around. Do take a coupla hours to read up on power management generally. Since forcing the rate of charge is NOT an option you need to REDUCE CONSUMPTION to keep your batteries from "going too low" so you cannot get them up again quickly enuff. It's just a fact of cruising that you cannot be as cavalier about your electrical power as you can be on land :-)!

TP

Stu Jackson 12-11-2019 14:33

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by Santiano (Post 3011495)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>
I went to the batteries to check for loose connections and found a negative terminal sparking where the charger was connected. Without turning the charger off, I rearranged and tightened the connection to the negative terminal. The terminal sparked as I did so, and the charger light went from "batteries full" to dead. No lights.>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>


Cheers,

Santiano.




It appears that the charger was still on when he played with the negative wire.


Next time you mess with connections, please make sure everything you are working on is turned OFF.


And while you're doing all this troubleshooting, draw yourself a wiring diagram so you'll begin to see how it all works together.


Good luck.

Santiano 13-11-2019 14:48

Re: Troubleshooting Drained batteries and Dead Charger.
 
Right, so. I've got a new 20 amp marine charger coming today. This time I will only be charging batteries with the same Ah rating and use in a single bank.

I've gone through and checked for loose/corroded connections. I've also tried to identify faults in the DC circuits with my multimeter, but I'm not really sure what I'm looking for. Voltage drop? Resistance? Any recommendations or resources that will describe what I should be paying attention to? I'd rather not burn out a second charger.

a64pilot 13-11-2019 15:00

Re: Troubleshooting Drained batteries and Dead Charger.
 
Your not going to burn it out, if you make your connections before you power it up.
Now if it wonít work, take a voltage reading of the bank, if itís too low a lot of modern charges wonít come on line, I assume itís some sort of safety issue?
Whatís too low? I donít know, but would guess about 10 V or so, but that is a guess.

Santiano 13-11-2019 15:15

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by a64pilot (Post 3015221)
Your not going to burn it out, if you make your connections before you power it up.
Now if it wonít work, take a voltage reading of the bank, if itís too low a lot of modern charges wonít come on line, I assume itís some sort of safety issue?
Whatís too low? I donít know, but would guess about 10 V or so, but that is a guess.

Battery voltage shows 12.8 volts. I've topped it up with an automotive charger, which may have been unwise. But I couldn't just leave it discharged.
What's the best way to check connections with a multimeter?

a64pilot 13-11-2019 15:29

Re: Troubleshooting Drained batteries and Dead Charger.
 
Checking connections you look for zero resistance.
But battery connections you can almost always do visually. However it might not hurt to ohm out the wires themselves, especially if they are old.
Iíve seen the inside end of wires under the insulation be black and or green and have significant resistance as corrosion set in.

rbk 13-11-2019 15:35

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by a64pilot (Post 3015236)
Checking connections you look for zero resistance.
But battery connections you can almost always do visually. However it might not hurt to ohm out the wires themselves, especially if they are old.
Iíve seen the inside end of wires under the insulation be black and or green and have significant resistance as corrosion set in.

^^ x2 Just because the connection looks good on the outside and is tight, it does not mean there ins't more going on inside the casing, more so if the connections are open ended, the corrosion can creep way up inside the wire.

TrentePieds 13-11-2019 17:09

Re: Troubleshooting Drained batteries and Dead Charger.
 
Santiano:

Sounds like you are on the right track now :-)

There are, conceptually, only three circuits in your boat: 1) the 120V circuits which we will ignore for now. 2) the "housekeeping" circuits operating on 12V and demanding only low "draws", i.e. they are "low ampage" circuits, and 3) the Engine Starting circuit which is also a 12V circuit but carrying HIGH ampage (draw). High ampage circuits have FAT wires, low ampage circuits have skinny wires. Both kinds of circuits get their current from the battery/batteries.

There are different kinds of batteries, distinguished sometimes by their internal construction and sometime by their chemistry. Most likely what you have is "flooded" batteries with a liquid electrolyte. Such batteries require maintenance and therefore they have "caps" that permit you entry to each cell. What I do to know the SOC ("state of charge") of my two 27 series flooded (fake marine) "deep cycle" batteries is remove the caps, suck a little of the electrolyte from each cell into a hydrometer (a five-dollar gizmo that measures specific gravity), read it, put the electrolyte back in the cell from which it was taken and record the hydrometer reading in my log. We can come back to what the readings "should" be and what it means if they are not what they should be. You can get all sorts of fancy little meters to tell you SOC and other things about you electrics, and they are nice to have,but I think it's a wise sailor who can get along without them.

I imagine that you have about a 30HP engine. It matters not whether its the old Atomic 4 gas pot or whether it's a diesel. The AMOUNT of current required to start it is so little that you DON'T need a separate "starter battery". I don't have one, and I "even out" the "wear" on the batteries by setting the selector to Batt #1 on odd numbered dates and to Batt #2 on even numbered dates. So think about this: My little Beta 20HP engine requires 15 seconds of preheat. Let's call it 1/4 minute drawing 75 amps. 1/4 minute is 1/4 x 1/60 of an hour = 1/240 hour. 75 amps for 1/240 hour = 0.3125 amp hours. After that the starter motor will require 200 amps also for 15 seconds. Same kinda calculation: 200/240 = .83333 amp hours for a total of 0.3125 + .83333 = 1.1458 amp hours, so let's be generous and call it 2 amp hours to start.

Now, the alternator on the Beta is rated at 40A but in actuality it wouldn't like to be asked turn out 40A continuously. When the engine starts it will turn out something like 15A and do that continuously. But I only need to replace 2 amp hours after starting, so at 15A it will take 60 minutes x 2/15 = 8 minutes to replace everything I took out of the batts to start. In practice, that means that just getting out of my slip replaces all juice used to start the engine. Your numbers will be slightly different, and you should determine what they are and do the calculations just because being able to do that confers protection against eager salesmen :-)

The charger you just bought will be made so it can tell the SOC of your battery bank. It's probably got two output terminals so you can wire each terminal to a separate battery. It will also have a special third terminal from which you take wire to the NEGATIVE terminal on one battery. This is how the charger gets to know whether the batteries are charging "too fast" which could happen because the charger is able to "push out" juice faster than is good for the batteries. The charger also senses the SOC of the batteries, and knowing that it will adjust itself to charge at one of three rates: 1) Bulk, 2) Absorption and 3) Float. On my charger they are called "Equalize", 'Bulk" and "Maintenance", That doesn't matter because both the charger and I know what the charger is doing. What happens chemically and electrically at each of these rates of charge is really, really fascinating, but there is no need for you know it at this point. Your new charger is gonna see you right. Provided you connect it correctly :-)

So if your entire wiring system is neat and clean so there are no short circuits or loose terminals anywhere, you troubles should be over. Remember that your bilge pump is wired for safety's sake so it will switch on automatically when required even when there is no-one in the boat. That can drain a battery fairly fast if you are taking in water, say through the stuffing box. But with your new charger more juice will be supplied to the batts than a bilge pump will drain out of them so you'll be okay in that respect.

Before you spend money on extra charging capacity I recommend that you spend it on REDUCING DRAW. The more modest your energy budget, the quicker you can get back to "full charge" after a night on "the hook" Wherever you can, substitute LED lights for incandescents. Learn to live without a refrigerator, learn to live without a water maker. Your expenditures of both money, effort and emotions will be reduced drastically if you go that way about it :-)!

All the best

TrentePieds

Santiano 13-11-2019 17:46

Re: Troubleshooting Drained batteries and Dead Charger.
 
Awesome write-up, TreintePieds!

I'm already doing without a reefer system or water maker, and have just ordered a bunch of LEDs to replace all my old incandescents. On the right track, as you say.

I've just been reading up on the "marine surveyor" link, and the man cited a report saying it's bad for 12v batteries to be wired in parallel! Everyone I know wires a 12v bank in parallel! Should I ignore this injunction?

boatpoker 13-11-2019 18:03

Re: Troubleshooting Drained batteries and Dead Charger.
 
The 12volt Bible
https://www.amazon.com/12-Volt-Bible.../dp/0071392335

noelex 77 14-11-2019 04:05

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by TrentePieds (Post 3015291)
My little Beta 20HP engine requires 15 seconds of preheat. Let's call it 1/4 minute drawing 75 amps. 1/4 minute is 1/4 x 1/60 of an hour = 1/240 hour. 75 amps for 1/240 hour = 0.3125 amp hours. After that the starter motor will require 200 amps also for 15 seconds. Same kinda calculation: 200/240 = .83333 amp hours for a total of 0.3125 + .83333 = 1.1458 amp hours, so let's be generous and call it 2 amp hours to start.

The amp hour draw starting a diesel engine is tiny, as you have pointed out. 2 AHrs is nothing even to a small battery. Ten AA batteries contain more than this amount of energy.

However, the current draw is very significant. The battery must be healthy to supply a high starting current.

The idea behind separate start and house banks is to ensure that one system will be available that can supply this necessary current. Without the ability to deliver these high currents, the engine will not start. There is little point calculating the energy draw because this not the limiting factor.

GordMay 14-11-2019 04:45

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by noelex 77 (Post 3011628)
...
A 6 amp charger is small but providing your electrical needs are modest it should manage fine. 6amps over 24 hours is 144 Ahrs. Many battery chargers will not supply their rated capacity continuously and there are some conversion inefficiencies, so you might have a little less than this, but providing you are not using more than around 120AHrs a day the battery should slowly charge...

The coulometric charging efficiency of flooded lead acid batteries is typically about 70 - 80%, meaning that you must put as much as 142 amp hours into the battery for every 100 amp hours you get out. This varies somewhat depending on the temperature, speed of charge, and battery type.

noelex 77 14-11-2019 05:21

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by GordMay (Post 3015489)
The coulometric charging efficiency of flooded lead acid batteries is typically about 70%, meaning that you must put 142 amp hours into the battery for every 100 amp hours you get out. This varies somewhat depending on the temperature, speed of charge, and battery type.

Not in this case.

The calculations were for the situation when the shore charger is on 24/7. The charger will therefore be supplying nearly all the power (only when the load is above 6A does this not apply) so the coulometric charging efficiency will rarely come into play. The majority of the energy is not charged and then extracted from the battery.

There will be some energy consumed by the battery (and converted to heat) maintaining the float voltage, especially if this cannot be lowered to the more appropriate storage voltage. This is quite different to the coulometric charging efficiency. The current will only be small for a healthy battery.

The largest unknown is if the battery charger can supply its 6A rated output on a continuous basis. Some can (so there are honest manufacturers out there:)), but many cannot and the shortfall can be significant.

Stu Jackson 14-11-2019 10:44

Re: Troubleshooting Drained batteries and Dead Charger.
 
https://www.amazon.com/Boatowners-Il...s=books&sr=1-3


This ^^^ is a very good boat electrical book.


You could also Google "How to use a multi-meter."


Good luck, keep at it.

boatpoker 14-11-2019 10:49

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by Santiano (Post 3015317)

I've just been reading up on the "marine surveyor" link,

Which "marine surveyor" link ?

skenn_ie 22-11-2019 07:56

Re: Troubleshooting Drained batteries and Dead Charger.
 
Quote:

Originally Posted by smac999 (Post 3011518)
A 6 a charger is way to small to keep a battery charged while on the boat.

That was my first thought.

OleBird 22-11-2019 09:37

Re: Troubleshooting Drained batteries and Dead Charger.
 
Here's a trick that might recover your battery if its not damaged.



Connect a similar battery in parallel, + to +, - to -, then connect and turn on your charger. Let it charge for 12 to 15 hrs - monitor the batteries to make sure they are not running hot - charger too. This will "fool" the charger and let it try to charge both batteries. If the original battery is not damaged (warped and shorted plates) it should recharge. I've only done this successfully with flooded lead acid batteries. AGM's are a little different animal.


Always, always disconnect the charger, the negative side of your battery first - then the positive - and never work on the dc system with the battery connected. In addition to a hydrogen gas hazard, a 12 volt battery can easily melt a cresent wrench in your hand resulting is serious burn that can be very hard to heal. Never wear rings or other jewelry when working on DC - or AC powered systems.



It's not black magic, but some knowledge of basic electricity will help and keep you out of trouble. READ UP!:wink:

Cheechako 22-11-2019 09:55

Re: Troubleshooting Drained batteries and Dead Charger.
 
1) Check the water in the batteries. If low fill and recharge.
2)Charge the batteries a good long time. Then disconnect the + cables to the batteries. Check each battery voltage after it sits overnight or a few hours. They should be about the same. Maybe 12.4 volts. If one is quite low you have a shorted battery which has been draining the rest down.

# 2 is fairly common. The shorted battery will be quite warm while/immediately after charging.

Ionlydream 22-11-2019 12:21

Re: Troubleshooting Drained batteries and Dead Charger.
 
I don't think that most people have not really touched on your problem. I think that your charger is dead! With a dead charger it does not matter what shape your battery is in or what you use....

Get a new charger! Before replacing the old charge (and someone did mention this) ensure that your system does not have a short circuit. Get, borrow, (temporarily steal from your car) a battery that you know is charged. Disconnect the battery in the boat, turn off all electrical and electronics on the boat. Using a set of jumpers connect the known good battery, if there is a spark you need to look for crossed wiring or a short circuit somewhere. This needs to be dealt with before doing anything else.

If there is not spark, start turning on devices 1 at a time, only every having 1 device on. If they all work then you should be okay replacing the charger and once the battery has charged (let it fully charge) you can then start using the devices again.

As long as you have the boat battery disconnected it might not hurt to take it to a garage or a store that does batteries and have them test it to ensure it's is working well.

Good Luck

Disailor 24-11-2019 21:57

Re: Troubleshooting Drained batteries and Dead Charger.
 
My grp27 batts are under the 1/4 berth mattress - pain to get to. Solution was a piece of almost mattress sized plywood that is hinged at the outboard edge & fitted with a ratcheting block/tackle. Pull a rope & batts are exposed! Oh yeah, to fill them I use an enema bag with the squeeze shut-off. One hand has flashlight the other to water filling tube. A delight to use!


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