I'm starting a new thread, just so I don't hijack the other one about battery charging...
After doing research on various forums and websites I believe I know the answer to this question already, but just to be certain...
My trailer is a 2001 that was bought used 2 years ago. The original battery, with a date code of 6/01, was still on it (Interstate 24M-RD, with a paltry RC of 75). I have no idea how/if it was cared for by the previous owner.
Having been a tent camper for years and years means I'm quiet familiar with dry camping, and had intended to do mostly that even with the trailer. However, with a wife and 3 daughters "convincing" me that things like an A/C or microwave were mandatory it soon became apparent that we were going to be camping on electric sites more often then not. As such, we had only used that battery on rare occasions.
This year, with all but one of the girls feeling as though they were too old to camp with us, I made the push to do a little more dry camping. But heat, lights, water pumps, etc. do take juice -- even for a measly weekend camping trip -- so I bought an Interstate SRM-24, with an RC of 140. Not too shabby for a group 24. Based upon feedback I also bought a BatteryMINDER to keep it charged, and up until recently I thought it was doing that job quiet well. Apparently, I was wrong...
When I got the new battery home the first thing I did was check the water level, which was just about perfect. I added a small amount of distilled to 1 or 2 cells, but even that was minimal. The BatteryMINDER took about 2 days to get to the fully charged state, but in total it was hooked up for 12 days before we went camping.
The maximum voltage during charging was 13.49, which "settled down" to 12.51 after the battery had been disconnected from the charger for 24 hours. From all I've read that seemed to be on the low side; most information implies that after 24 hours off the charger the voltage should be closer to 12.80, so I was already concerned.
The weekend (3 days, 2 nights) we went camping had cold evenings -- into the low 40's one night -- but we only used the heat while we slept. Light and water pump usage was very minor, so I assumed we should be fine with the brand new battery. We weren't; about 3AM on the 2nd night we were awoken by the propane detectors low voltage alarm. Essentially, we ran out of battery
When we got home I disconnected the battery and let it sit for 24 hours, at which time it measured a ridiculous 11.82 volts! The water level was still fine, and after about 36 hours on the BatteryMINDER it's reached the fully charged state again.
Obviously something is wrong, and I suspect it's that the BatteryMINDER isn't fully charging the battery because it only puts out around 13.50 volts. Most of the posts regarding three-stage charges indicate that they're putting out 14.50 (or more) volts.
At this point it appears to me that I need to get a "real" battery charger. Is that what it sounds like to you as well? I found the Vector 1093A for $80 at Northern Tool (it has a list price of $120, which seems like a pretty good deal), so I'm thinking about getting that to charge the battery and just using the BatteryMINDER to keep it "topped off".
The BatteryMINDER isn't really a charger, it is meant to "hold" the charge that's already there.
All-in-all, trickle chargers are not the best thing for a battery, even a fully charged one that's in storage.
Do you tow with the fridge on 12V? Depending on the charge line from your tow vehicle, that could end up partially draining the camper battery. Using 12V is OK if you are going to be plugged in, but I use propane while towing if I expect to be dry camping. I don't use anything if I'm only towing a couple hours or less.
Austin
The battery minder is floating at 13.5V, it is doing fine.
http://www.thebatteryminder.com/12v133abatteryminder-p-29.html (//%22http://www.thebatteryminder.com/12v133abatteryminder-p-29.html%22)
The website states that it DOES charge at 14.2-14.4V then float at 13.4V
I suspect your battery is toast. Let it fully charge then disconnect for 4-5 days. I think you will find it is a goner or close to it.
If you want a good 3 stage charger, check out WalMart. They carry a Black and Decker brand that is manufactured by Vector. It has charging algorithms for wet, AGM and GEL. It also has desulfate and equalize modes. You may be able to run your existing battery through a couple of desulfate cycles (~24 hours each) then equalize charge it and still get some good use out of it.
I recommend buying a battery hydrometer to find the true state of charge and equalize until you have the cells close to the same.
Quote from: chasd60I suspect your battery is toast. Let it fully charge then disconnect for 4-5 days. I think you will find it is a goner or close to it.
Did you read his post? The battery is brand new.
Austin
Quote from: AustinBostonDid you read his post? The battery is brand new.
Austin
New batteries that go flat dead before you buy them are no different than old batteries that go flat dead after you buy them. A brand new battery that takes two days to get to full charge with a charger that puts out 1A isn't a good sign. Best to check the datecode on the battery and the voltage prior to buying it. The batteryMINDER maintains the battery based upon demand and is in the milliamps, not a trickle charger.
BTW, the furnace uses 4-5A when running.
I'd be looking at how much peak draw you're pulling out of the battery before doing anything else. I have an Interstate SRM27 with RC 160. With 2 lites, a cooling fan, and a cell phone hooked up I'm drawing just under 3 amps. I actually had everything hooked up in the back yard to test. Ran everything nonstop for the entire weekend from friday nite around 5pm thru sun nite on just the battery and they were still going strong ( fan seemed to be a little slower) when I checked them sun nite about 9pm. It finally drained down sometime Monday morn cause it was dead when I checked at 9am Mon.
Quote from: chasd60A brand new battery that takes two days to get to full charge with a charger that puts out 1A isn't a good sign.
Is that a typo? Two days at 1A is 24 amp-hours. That's not much on even a small group 24 battery. I expect my group 24 battery (which is in good condition) to draw 6 amps for 24 hours or more when it goes below 12 volts.
Also, if you put 14.4 volts on any battery (even a fully charged one) you would get a lot more than one amp. After reading the site, I think the batteryMINDER may give pulses of much higher current (at 14.x volts), but that they are short pulses that average only one amp (i.e. 4 amps for 1/4 second, 0 amps for 3/4 second). If it really charges the battery, it takes a loooong time to do so.
Austin
Quote from: AustinBostonDo you tow with the fridge on 12V? Depending on the charge line from your tow vehicle, that could end up partially draining the camper battery. Using 12V is OK if you are going to be plugged in, but I use propane while towing if I expect to be dry camping. I don't use anything if I'm only towing a couple hours or less.
I actually have a TT, so the refer doesn't work on 12V's only. I do tow with it using propane, but the amount of current draw off the battery for that should be minimal. The charge line fuse has been pulled because I was always leery of stopping someplace and having it drain my TV's battery, leaving us with no way to start the truck.
Quote from: chasd60The website states that it DOES charge at 14.2-14.4V then float at 13.4V
That's actually one of the reasons I bought it, because I was under the impression it would charge at 14+ volts. But it doesn't; the highest voltage I've ever seen was 13.50. Once it reaches the fully charged state it bounces back and forth between 13.48 and 13.49, but never higher then 13.50.
Quote from: chasd60I suspect your battery is toast. Let it fully charge then disconnect for 4-5 days. I think you will find it is a goner or close to it.
I certainly hope not! The darn thing is brand new.
Quote from: chasd60If you want a good 3 stage charger, check out WalMart. They carry a Black and Decker brand that is manufactured by Vector. It has charging algorithms for wet, AGM and GEL. It also has desulfate and equalize modes. You may be able to run your existing battery through a couple of desulfate cycles (~24 hours each) then equalize charge it and still get some good use out of it.
I was strongly leaning towards
this one.
If the heater draws 4-5 amps when running, and the water pump if it's similar to a bilge pump on a boat draws about 1-2 amps and say 1 amp for lites were talking around 6-8 amps draw. Now all we need to know is about how long each was used. I'd use an ammetter to find out what you're actually using as far as power. Definitely get a hydrometer to check your battery state too. You can't just go by voltage readings alone. You may have a battery with a weak cell, but I'd do specific gravity readings and some calculating first. I'm thinking you either have too much tail and not enough kite or you have a weak battery.
Replacing the battery may or may not solve your problem.
Just my opinion, but that's how I'd approach the problem. Anyway good luck and let us know what you find.
Quote from: jawilsonThat's actually one of the reasons I bought it, because I was under the impression it would charge at 14+ volts. But it doesn't; the highest voltage I've ever seen was 13.50. Once it reaches the fully charged state it bounces back and forth between 13.48 and 13.49, but never higher then 13.50.
I certainly hope not! The darn thing is brand new.
I was strongly leaning towards this one.
That's a great charger. Been wanting one for awhile.
Here's a link that is very helpful....
http://www.ccis.com/home/mnemeth/12volt/12volt.htm
Good luck.
I'm not sure b/c I own a Ford, but IIRC I remember hearing the Chevy guys saying something about having to purchase/install a relay under the hood to get the charge line hot. In my Ford, the relay came with the brake controller pig tail and there were instructions about installing it under the hood. That being said, if you do have a relay installed, it kills power to the charge line when the TV isn't running. Therefore, no worries about a dead starting battery b/c it's disconnected automatically. You can check that with a test light or a multi-meter if you aren't sure. I'd be surprised if you don't have the relay....If you don't, you can install it and that would stop your worries. But, seeing that you've pulled the fuse, I guess you don't have any worries about it anyway :D
travis
Quote from: jawilsonI certainly hope not! The darn thing is brand new.
New batteries go bad too. Don't live in denial..and don't drive yourself crazy :banghead: trying to guess what the problem is. It's easy to test the battery, to be sure. :D
You might want to get yourself a hydrometer. Charge the battery then let it set for 24 hours. Check the specific gravity of each cell with the hydrometer. Each cell should read pretty close to the same, if one cell reads lower than the rest, it's bad (or at least weak). A bad/weak cell will drain the other cells down.
If the battery is under 12 months old, they will probably just exchange it for a new one. If it's over 12 months, they may prorate it.
If the specific gravity tests good on every cell......well.... then you can start :banghead:
Quote from: waveryNew batteries go bad too. Don't live in denial...
I agree...
don't deny that a ONE AMP charger is a tiny trickle charger that can take weeks to bring a battery up to charge. My cheap manual charger has a low setting...that is 2 amps. Whether or not the battery is good, the device he has does not qualify as a battery charger, even for a group 24 battery.
Austin
Quote from: AustinBostonI agree...don't deny that a ONE AMP charger is a tiny trickle charger that can take weeks to bring a battery up to charge. My cheap manual charger has a low setting...that is 2 amps. Whether or not the battery is good, the device he has does not qualify as a battery charger, even for a group 24 battery.
Austin
A trickle charger charges at a constant rate without regards to state of charge of the battery, This charger does not do that, it adjusts the rate of charge based upon battery state of charge.
From the website
Float Current5 mA - 200 mA*
* Actual current output is determined by individual battery demand.
You believe 2A does qualify as a battery charger but 1.33A as stated by the manufacturer does not?
(Battery) charger: a device for charging or recharging batteries
wordnet.princeton.edu/perl/webwn
Quote from: AustinBostonIs that a typo? Two days at 1A is 24 amp-hours. That's not much on even a small group 24 battery.
The original post stated it took two days to charge the new battery.
Quote from: AustinBostonI expect my group 24 battery (which is in good condition) to draw 6 amps for 24 hours or more when it goes below 12 volts.
I expect you will be in for a surprise. A group 24 only has about 85A/H capacity and that would be 100% discharge. Unless you proportionately increase the laod when the voltage drops off, you won't maintain a 6A load.
Quote from: AustinBostonAlso, if you put 14.4 volts on any battery (even a fully charged one) you would get a lot more than one amp.
Amperage is not a function of voltage, you can put out 1mA at 100V and you can put out 100A at 1V.
Quote from: AustinBostonAfter reading the site, I think the batteryMINDER may give pulses of much higher current (at 14.x volts), but that they are short pulses that average only one amp (i.e. 4 amps for 1/4 second, 0 amps for 3/4 second). If it really charges the battery, it takes a loooong time to do so.
Austin
From the website (my emphasis)
The unit automatically desulphates in the maintenance mode after it completes the charging cycle. Desulphation Pulse1.33A @ 3.26 MHz
That is 3.26 million times per second
Quote from: waveryYou might want to get yourself a hydrometer.
You know, this is one of those things I've said I needed for years. But every time I go into the auto parts store for something I forget to pick one up. Maybe it's time I just write myself a note...
Quote from: chasd60A trickle charger charges at a constant rate without regards to state of charge of the battery, This charger does not do that, it adjusts the rate of charge based upon battery state of charge.
From the website
Float Current 5 mA - 200 mA*
* Actual current output is determined by individual battery demand.
In any case .005A (5 mA) - 0.2 A (200 mA) does not a battery charger make. My converter will put 25 amps (motre than 100 times as much as 200 mA) into the battery.
QuoteYou believe 2A does qualify as a battery charger but 1.33A as stated by the manufacturer does not?
Absolutely not. The 2A setting is little more than a trickle charge; I said it was the "low" setting. It's a
small charger when on the
High setting (6 amps).
Austin
Quote from: chasd60I expect you will be in for a surprise. A group 24 only has about 85A/H capacity and that would be 100% discharge. Unless you proportionately increase the laod when the voltage drops off, you won't maintain a 6A load.
Yes, my statement is an oversimplification. It would start at 6 amps, and gradually drop to somewhere around 3 (at which point I would take it off the charger). The average current would be 4.5 amps.
QuoteAmperage is not a function of voltage, you can put out 1mA at 100V and you can put out 100A at 1V.
What???? The single most basic electrical formula there is (Ohm's law) says that it is:
E = I x R
Where E is voltage, I is current, and R is resistance. Solved for current, we get:
I = E / R
Unless you change the resistance, the current is a DIRECT function of the voltage. When talking battery charging, there are only two ways to change the resistance - charge the battery, or put in a different battery. So if you want to change the current (without changing the battery), you MUST change the voltage.
While you can put out 1 mA at 100 volts (or even 1,000,000 volts) and 1,000 amps at 1 volt, you
can't do that without huge changes in the resistance of the load. Within the context, the load is the battery being charged.
QuoteFrom the website (my emphasis)
The unit automatically desulphates in the maintenance mode after it completes the charging cycle.
Desulphation Pulse1.33A @ 3.26 MHz
That is 3.26 million times per second
And how long is the pulse? It could easily still have a duty cycle of 1%, so that the average current would be 0.0133 amps (133 mA).
But in reality, at 3.26 mhz, the battery acts like a huge capacitor, NOT a battery. No charging takes place at those frequencies, and the battery would look almost like a dead short to the device. You could get 1.33 amps to flow at about 15 mV above the battery charge level.
Before we go on, I worked for 13 years doing QA on electronic power supplies. Many times a day, I had to read specs and calculate the loads needed to test a very wide variety of devices with DC inputs from 5 to 48 volts and DC outputs from 1.2 to 1,500 volts. A mistake could fry a device (or a test jig).
I also had to calculate leakage currents for transformers that had to be safety tested at up to 8,000 volts DC and 1,500 volts AC; these devices were used in medical equipment where failure could be lethal. I had to write out and sign my test results. If there was a problem, guess who was going to be in trouble? I had to be right, and I did it every day.
Austin
Quote from: AustinBostonYes, my statement is an oversimplification. It would start at 6 amps, and gradually drop to somewhere around 3 (at which point I would take it off the charger). The average current would be 4.5 amps.
What???? The single most basic electrical formula there is (Ohm's law) says that it is:
E = I x R
Where E is voltage, I is current, and R is resistance. Solved for current, we get:
I = E / R
Unless you change the resistance, the current is a DIRECT function of the voltage. When talking battery charging, there are only two ways to change the resistance - charge the battery, or put in a different battery. So if you want to change the current (without changing the battery), you MUST change the voltage.
While you can put out 1 mA at 100 volts (or even 1,000,000 volts) and 1,000 amps at 1 volt, you can't do that without huge changes in the resistance of the load. Within the context, the load is the battery being charged.
And how long is the pulse? It could easily still have a duty cycle of 1%, so that the average current would be 0.0133 amps (133 mA).
But in reality, at 3.26 mhz, the battery acts like a huge capacitor, NOT a battery. No charging takes place at those frequencies, and the battery would look almost like a dead short to the device. You could get 1.33 amps to flow at about 15 mV above the battery charge level.
Before we go on, I worked for 13 years doing QA on electronic power supplies. Many times a day, I had to read specs and calculate the loads needed to test a very wide variety of devices with DC inputs from 5 to 48 volts and DC outputs from 1.2 to 1,500 volts. A mistake could fry a device (or a test jig).
I also had to calculate leakage currents for transformers that had to be safety tested at up to 8,000 volts DC and 1,500 volts AC; these devices were used in medical equipment where failure could be lethal. I had to write out and sign my test results. If there was a problem, guess who was going to be in trouble? I had to be right, and I did it every day.
Austin
You added R to my statement. R is a function of battery state of charge. Battery resistance changes with SOC (state of charge). Battery chargers work in reaction to the change in resistance therefore the output of a charger is proportionate to the internal resistance of the battery within the limits of the programmed algorithm in a smart charger.
I would continue with this discussion but backing up each little piece of data I present takes too long to fully document. I appreciate your background of many years ago AB.
I work as an Assistant Engineeer in the Corporate Reliability Lab of a Semiconductor manufacturer and my degree is in Electromechanical Technology.
I not only read the specs you referred to but I also write them in accordance with accepted industry standards, military standards and automotive standards.
I maintain, upgrade, automate and design equipment for our corporate lab as well as site labs that are located all over the world.
We make logic, swith, analog power, signal conditioning and discrete devices and all of these pass through our lab at one time or another. Some of them high frequency and some of them straight DC.
I can back up everything I present with knowledge and references from today but it doesn't seem that it would be minimize any disagreement and I don't have the time to research, document and argue.
The BatteryMINDER
IS enough and that is my final answer.:p
Quote from: chasd60You added R to my statement. R is a function of battery state of charge. Battery resistance changes with SOC (state of charge). Battery chargers work in reaction to the change in resistance therefore the output of a charger is proportionate to the internal reistance of the battery within the limits of the programmed algorithm in a smart charger.
I would continue with this discussion but backing up each little piece of data I present takes too long to fully document. I appreciate your background of many years ago AB.
I work as an Assistant Engineeer in the Corporate Reliability Lab of a Semiconductor manufacturer and my degree is in Electromechanical Technology.
I not only read the specs you referred to but I also write them in accordance with accepted industry standards, military standards and automotive standards.
I maintain, upgrade, automate and design equipment for our corporate lab as well as site labs that are loacated all over the world.
We make logic, swith, analog power, signal conditioning and discrete devices and all of these pass through our lab at one time or another. Some of them high frequency and some of them straight DC.
I can back up everything I present with knowledge and references from today but it doesn't seem that it would be minimize any disagreement and I don't have the time to research, document and argue.
The BatteryMINDER IS enough and that is my final answer.:p
YAAA!!
.
.
.
What he said :p
So a 6 amp battery charger isn't enough?
Quote from: dirtracinSo a 6 amp battery charger isn't enough?
I've used a 6amp charger for over 20 years on my deep cycle batteries for my boats and never had a problem.
Just what I want to hear, thanks
Rick
Quote from: Nemesis56I've used a 6amp charger for over 20 years on my deep cycle batteries for my boats and never had a problem.
Quote from: waveryYAAA!!
.
.
.
What he said :p
So you say a 1 amp charger is not a trickle charger?
Austin
Quote from: chasd60You added R to my statement. R is a function of battery state of charge. Battery resistance changes with SOC (state of charge). Battery chargers work in reaction to the change in resistance therefore the output of a charger is proportionate to the internal resistance of the battery within the limits of the programmed algorithm in a smart charger.
And they do this by, um,
changing the voltage!Is there a problem with the formula I posted?
Is there a problem with anything I posted?
Do you have ANYTHING, to back up your statement
"Amperage is not a function of voltage?"If I posted 500 words refuting the statement,
with facts, you might just try...even a link to a web site or something.
I posted all that crap about my experience because every time I talk about the facts with electricity people make long-winded but utterly irrelevant analogies. If you have facts, that would be fine. If there is something I am missing, that would be fine.
But if 10% of the stuff you posted about yourself is true, then you know that the only way to push more current through a battery is to increase the applied voltage or to discharge the battery.
Current IS directly proportional to voltage. The fact that it is also inversely proportional to the resistance doesn't make that untrue.
I still stand by my assessment. The BatteryMINDER is a maintenance device; it is not a charger.
Austin
Quote from: AustinBostonAnd they do this by, um, changing the voltage!
Is there a problem with the formula I posted?
Is there a problem with anything I posted?
Do you have ANYTHING, to back up your statement "Amperage is not a function of voltage?"
If I posted 500 words refuting the statement, with facts, you might just try...even a link to a web site or something.
I posted all that crap about my experience because every time I talk about the facts with electricity people make long-winded but utterly irrelevant analogies. If you have facts, that would be fine. If there is something I am missing, that would be fine.
But if 10% of the stuff you posted about yourself is true, then you know that the only way to push more current through a battery is to increase the applied voltage or to discharge the battery. Current IS directly proportional to voltage. The fact that it is also inversely proportional to the resistance doesn't make that untrue.
I still stand by my assessment. The BatteryMINDER is a maintenance device; it is not a charger.
Austin
Reread the entire first page of this topic and you can see where any response posted, even with links to the manufacturers website, you argued about. I should have known better and only responded to the originator of the topic. It is no longer worth my time to respond to you because no matter the response, it is incorrect in your eyes.
And FYI, a trickle charger outputs a constant current without regard to battery state of charge, whether it be 1A or 2A. This device changes to "float" as I previously stated, Wavery doesn't need to point that out to you, I have already done so in a previous post you seem to want to ignore.
Geez, maybe I should jump back in now... :yikes: :p
I went out and bought the Black & Decker 1093DBD, which seems to have just about every option under the sun. I'm now in the process of playing around with it on the original, 6 year old, half dead battery (just in case I do something wrong don't want to blow up the new one :)).
So far everything looks to be working, but time will tell. I plan on using the "real" charger once a month while the battery is in storage, with the BatteryMINDER hooked up in between. We'll see how I do on the next dry camping trip doing that.
Quote from: jawilsonGeez, maybe I should jump back in now... :yikes: :p
I went out and bought the Black & Decker 1093DBD, which seems to have just about every option under the sun. I'm now in the process of playing around with it on the original, 6 year old, half dead battery (just in case I do something wrong don't want to blow up the new one :)).
So far everything looks to be working, but time will tell. I plan on using the "real" charger once a month while the battery is in storage, with the BatteryMINDER hooked up in between. We'll see how I do on the next dry camping trip doing that.
That's cool!!
Get a hydrometer so you will only equalize when necessary. It seems like the desulfation mode is similar to the same mode in the BatteryMINDER, low current with high frequency pulses to dislodge the sulfates on the battery plates.
I have tried to revive a tired old group 24 from my popup with no luck. I pretty much ran it down to low lighting conditions several times which is below low recommended discharge level.
Quote from: chasd60The BatteryMINDER IS enough and that is my final answer.:p
Except when I am connected to shore power, the BatteryMINDer is the only charger I use and the only charger I have
ever used.
Quote from: AustinBostonI still stand by my assessment. The BatteryMINDER is a maintenance device; it is not a charger.
I have the model 12112, stated output of 1 amp at 12vdc. I have monitered the charger and it has charged for as long as 48 hours before going to desulphate mode on each of my group 27 batteries after 4 days/nights dry camping. Either my batteries really started with some power or the BatteryMINDer
IS a charger. During the summer months, I exclusively dry camp and charge only with the BatteryMINDer.
AB, your assessment is wrong, no matter what your formulas tell you.