My Nipper is parked up at my ex's place, and last week I was heading away for a few days, so asked my son to plug her in to cool down the fridge, and put the battery charger on the in house battery. Which he did.
When I went to turn on a light on the first night, no light. I had my solar light so it wasn't a problem that night. I also had my solar panel with me.
When the rest of my group arrived the next morning, I just asked if someone could take a look for me. This friends s-i-l told me that my 'normal' battery charger wasn't right for charging a deep cell battery. Is that true?
My brother-in-law had suggested I buy a battery charger some time ago, so I did, and this is the first time I've used it. He didn't tell me to get a specific type of charger though.
Dougwe said
01:25 AM Aug 31, 2013
Not sure about the battery charger Beth but did you check fuses? I had similar problems last year before the big 12v upgrade and found it to be fuses.
I just have a 240v - 12v charger hooked up for charging by 240v and a duel DC-DC Cteck Smartcharger hooked up for all the 12v side of things including the solar panel.
Beth54 said
01:44 AM Aug 31, 2013
Yes, he checked the fuses first off.
I have a ciggie plug in the van to charge the phone and laptop...laptop has a converter thingy from Jaycar. I've been using that for a couple of years with no problems.
Otherwise, I only have two solar lights, and a couple of torches. The solar panel charges the battery really well, but bil suggested it's a good idea to charge the battery off 240 occasionally to give it a full charge.
This bloke's a bit of a know it all, so I'm not totally believing what he's said until I ask around. I could ring Battery World or other, but thought I'd ask here first.
bill12 said
01:54 AM Aug 31, 2013
Is there anybody close who has a multimeter ? Check the voltage in the battery and then connect the charger. Wait for couple of hours and see if there is any difference in the voltage. This will tell you if the charger is working, and if the battery is taking charge. My batterys go to 14v during the day ,and 12.7v at night.I hope this helps. Bill
Beth54 said
02:00 AM Aug 31, 2013
I have a multimeter, which he used and found it was charging fine once the solar panel was hooked up.
There was no power at this place to try out the battery charger again. It's a brand new charger and son said it was working when he checked on it before I left that morning.
What I'm asking is, does one need a 'special' battery charger for deep cell batteries, or should a regular charger do the job?
GypsyBob said
02:26 AM Aug 31, 2013
Beth54 wrote:What I'm asking is, does one need a 'special' battery charger for deep cell batteries, or should a regular charger do the job?
No you don't need a special charger for deep cycle, yes a 'regular' charger will do an okay job. There are a few types of deep cycle battery, Gel, Glass Mat, Calcium, 'normal' Wet cell and a few others. Most non deep cycle batteries are wet cells and there is no difference in charging a car wet cell and a deep cycle wet cell.
An intelligent charger (or muliti phase) will do a better job of charging a deep cycle battery than a non intelligent battery charger. Different types of battery have different 'ideal' voltages for charging them. Normal wet cell batteries prefer 14.7V, AGM (glass mat) prefer 14.4V and Gel batteries 14.1V. The multi phase chargers usually start off by slowly charging the battery on a low current, then powering up to high for a while, then slowing down as the battery gets full, then checking that the battery is holding the charge then just drip feeding it until you take it off the charger.
PeterD said
05:10 AM Aug 31, 2013
Beth54 wrote:What I'm asking is, does one need a 'special' battery charger for deep cell batteries, or should a regular charger do the job?
What do you refer to as a "regular charger?" Not all chargers are equal. If you purchased a cheap charger from one of the chain stores it is possible that you have done some damage to your battery. If you can give us some makers names and part numbers of what you have installed we can give some accurate advice and you will not have to read through the usual duff gen that follows from lack of info.
What a lot of people think of as a regular charger is cheap ones from the like of SuperCheap and Big W, The special thing you need is a charger that is tailored to the characteristics of your battery. You need a multi stage charger. I described the workings of a multi stage charger in this thread. Looks like some here did not rad my posting very well.
Nomadicman said
05:27 AM Aug 31, 2013
How can that be? My vehicle motor charges my normal vehicle battery and then when fully charged a relay switches to allow charging the deep cell battery. I understood the only function of the relay was to ensure that current only flowed to the deep cell when the vehicle battery was full. IF this is the case (is it?) then the alternator in the van is a charger for both types of battery.....isn't it??? And we need only one type of charger....????
Beth54 said
06:53 AM Aug 31, 2013
It looks like I'll have to take a drive out there tomorrow, and get a full description of the charger. It was a fairly cheap one from Supercheap, or maybe Repco. Can't remember which.
Obviously Peter, I didn't know all battery chargers weren't equal. Although I understand that there'd be different qualities, same as everything you buy. When bil suggested I get one, it seems I should have asked questions.
Hold that thought til tomorrow arvo peoples.
PeterD said
03:10 PM Aug 31, 2013
Nomadicman wrote:
IF this is the case (is it?) then the alternator in the van is a charger for both types of battery.....isn't it??? And we need only one type of charger....????
We are not talking of alternator charging. This thread is on 240 V AC chargers, a completely different kettle.
Seeing you raised the subject of alternator charging, read http://www.caravanandmotorhomebooks.com/articles/old/the-70percent-debate.html - this is still applicable to the older vehicles. However when you get to the modern vehicles you may find the alternator working at less than 13.8 V which is no sufficient to charge a battery in a van.
-- Edited by PeterD on Saturday 31st of August 2013 03:11:15 PM
GaryKelly said
04:25 PM Aug 31, 2013
The first time I used a charger, I didn't know the battery needed to be disconnected. Duh! I presume the deep cycle also needs to be disconnected before attaching a charger.
blaze said
05:21 PM Aug 31, 2013
GaryKelly wrote:
The first time I used a charger, I didn't know the battery needed to be disconnected. Duh! I presume the deep cycle also needs to be disconnected before attaching a charger.
Hi Gary
don't need to disconnect to charge, some people do but not nessary
cheers
blaze
Beth54 said
06:51 PM Aug 31, 2013
Well I didn't get to pick up the charger today, to find out the specifics of it. But I do know it's what I called an 'ordinary' charger, which I now know is called a 'wet' charger. And after doing some googling, which I should have done in the first place, I now have my answer. From here...
Never charge a sealed (gel cell) battery with a wet battery charger. The higher voltages (above 14.8 volts) that a wet battery charger generates causes excessive gassing too fast for the sealed battery to recombine, causing dry-out and battery failure.
If I'd realised it was going to be so hard to get a simple answer, I'd never have asked in the first place. Thanks anyway guys.
-- Edited by Beth54 on Saturday 31st of August 2013 06:51:56 PM
Teddy said
10:47 PM Aug 31, 2013
You do not need to disconect the battery prior to charging, it was suggested in earlier times to disconnect the battery in case the wrong connections were made but now with so many electronic devices on cars etc which forget all their settings when disconnected it it not possible or advisable
So the idea now is to get a new smart charger which also has protection for wrongfull connection.
mongrel said
12:20 AM Sep 1, 2013
Welcome to the forum Teddy..I must have missed you before ,sorry about that..Hope you enjoy the forum and the people ,good info and great ideas.
patrolst said
03:00 PM Sep 1, 2013
Hi Beth.
Where you have your van stored is it possible to connect the solar panel and may be position it on the roof and leave it connected till you use the van again, this way the battery will be maintained.
This may save the outlay of a new charger.
Beth54 said
08:11 PM Sep 1, 2013
patrolst wrote:
Hi Beth.
Where you have your van stored is it possible to connect the solar panel and may be position it on the roof and leave it connected till you use the van again, this way the battery will be maintained.
This may save the outlay of a new charger.
That's a thought. Yes I could easily do that. That would certainly save the extra expense.
I only bought the charger because my brother-in-law said it's a good idea to charge the battery on 240 occasionally.
Teddy said
02:00 AM Sep 4, 2013
Hi Beth
Although I agree mostly with the link that you supplied, one point may confuse some people
The danger that all batteries face is heat, heat produces explosive gasses and physically damages the construction of the battery.
But most people only have various forms of trickle charges which do not have the power to do damage as the article suggests because it is the current supply and not the voltage which produces the heat and trickle charges which pump out 2 to 4 amps will never be powerful enough to hurt.
As I said in an earlier post it is advisable to get one of the new smart battery chargers to be on the safe side but dont just throw away your good trickle charger to buy a new one for a gel battery
Think of the tassers in use now 50,000 to 400,000 volts and they certainly knock you down but they have minimal current, if you get hit with a bare wire on 230 volts you will die because there is a greater current supply.
Beth54 said
02:44 AM Sep 4, 2013
Thanks for that extra info Teddy.
VKPORTABLE said
03:13 PM Sep 5, 2013
I've always just used your generic battery chargers for all my batteries, be it wet cell or SLA. GypsyBob is correct, any charger will do just that, provide charge.
As for the post on dual-battery systems (Nomadicman) - yep the relay is just an automatic switch, which takes your second battery out of circuit once it is deemed fully charged by the said controller. This is so your second battery doesn't get drained when starting the engine or running lights and so on.
Beth54 said
06:33 PM Sep 5, 2013
VKPORTABLE wrote:
I've always just used your generic battery chargers for all my batteries, be it wet cell or SLA. GypsyBob is correct, any charger will do just that, provide charge.
As for the post on dual-battery systems (Nomadicman) - yep the relay is just an automatic switch, which takes your second battery out of circuit once it is deemed fully charged by the said controller. This is so your second battery doesn't get drained when starting the engine or running lights and so on.
So do you think charging it with the solar panel without anything running off it at the time, like lights or whatever, that that would be enough charge without the 240 charge? It's a 80 watt solar panel if that makes any difference.
patrolst said
07:20 PM Sep 5, 2013
Beth if the solar panel is connected and left exposed on the roof (maybe tied down so the wind won't blow it off) this will charge and maintain your battery with out any input from the 240vlt charger.
But under the circumstances you have the battery may have been over charged and been damaged and therefore not holding the charge as you have experienced on your last trip.
I would remove the battery and have it checked just to make sure that it is in good working order.
Baz421 said
07:51 PM Sep 5, 2013
Hi Beth
I think some of the advice you are getting is not appropriate and will not necessarily help you 100%.
I suggect you read PeterD's responses he gave you as he knows what he's talking about and provided some links to assist you. If you read the links it explains things a bit better.
As an example my brothers boat starting battery (wet cell) was always just starting his boat, always just. He used a small charger 4 amps output and left it on charge. However the charger didn't have the "grunt" to overcome the batteries internal resistance and charge it properly.
Eventually he took it to the garage and it took over 24 hours to fully charge it properly,,,staring at 30 amps current,,, his small charger would have never achieved this.
He now uses a multi stage charger to recharge it and he hasn't had a problem for 3 years.
I like examples as they can demonstrate what to some is a simple point but others may not have the experience to understand the tech jargon.
Hope this helps. Baz
Teddy said
08:35 PM Sep 5, 2013
I liked PeterD's explanation of the term multi stage charger rather than smart charger, except they are certainly smarter than a trickle charger.
A trickle charger does not have any control it just sends out a charge regardless and in certain cases can overcharge a battery in time.
When you have your battery connected to the car, it's charging system includes a regulator which controls the amount of charge that is sent to the battery and depending on the setting of that regulator will cut out at a prescribed voltage, and obviously the multi stage chargers have a similar function included.
As to a battery that gets very flat, a trickle charger usually does not have the grunt to overcome the sulfurization that occurs to the plates of the battery so a good hard charge is necessary for the battery to recover if it is not too far gone, think of a trickle charger as a machine to keep the battery charged rather than something to make it recover, certainly the non wet batteries do not like being flat at all and will usually never recover
Beth54 said
01:39 AM Sep 6, 2013
I'm sure PeterD is very knowledgeable, but I'm one of those people who has trouble understanding something technical by reading it. It has to be a simple explanation, or I need to see it done, or a diagram or something. Or, as Baz421 said, an example.
I'll pop out there on the weekend, as I meant to do last weekend, and get one of the blokes to check the battery, get the specifics of it and buy a suitable charger.
Thanks for all your suggestions fellas.
Ontos45 said
06:18 PM Sep 6, 2013
If your single 80Watt solar panel has a separate solar controller you can disconnect the solar panel and then connect your cheapo 240VAC battery charger outputs to the + and - that the solar panel came off. This turns the charger into a 3/4 stage charger depending on your solar controller. I have switch that disconnects/connects the solar panels and a 15Amp 240VAC power supply when near to Grid power. Took the idea from Colin Rivers books.
Peter
The dog lady said
09:04 AM Sep 9, 2013
Beth if he called it a deep "cell" battery I'd be very skeptical of his advice because he doesn't even know the correct terminology! They're deep cycle batteries, and you can use the same charger as for any car battery. (The term "cycle" refers to some of the characteristics of the battery and is important) Though not all chargers are created equal by any means! Get some professional advice if you're uncertain. It shouldn't cost you anything and you'll have peace of mind.
Beth54 said
08:20 PM Sep 9, 2013
I'm not sure I get the gist of that Peter, but I'll ask 'my' blokes.
Dog lady, I was the one calling it a deep cell battery. I plan to talk to a professional before I buy another charger anyway, but I spoke to my sil yesterday, and he also said the 'normal' charger shouldn't be used. And yes, I'm still calling it a 'normal' battery charger.
Baz421 said
08:30 PM Sep 9, 2013
OK here's another good section from the web and it's easy to understand,,,, compare this to a cheepie style that has one charge rate ie 4 amps max and tapers off to say 1/2 amp as voltage rises.
From web
For three or four stage chargers you will hear terms such as bulk or boost, absorption, float and storage phases.
Boost phase = is the first stage of the charging process. Essentially it is the stage where the charger puts in as much current it is capable of and as the battery storage voltage increases the charge rate decreases until the battery is about 75% full.
Absorption phase = this is the second stage of the charging process where the charge going in is reduced to about half of the boost rate or a constant rate for several hours (unless a heavy load is drawn and it will then cycle back to the boost stage).
Float phase = at this stage the battery charge is decreased again to about 97% of charge.
Storage phase = or maintenance stage is where there is constant voltage to maintain the battery at full capacity whilst maintaining any DC operating loads.
Baz421 said
08:37 PM Sep 9, 2013
More info from web. NOTE THE EXAMPLE FOR A SINGLE 120aH BATTERY WITH 40A CHARGER DISCHARGED TO 50% ---- TIME TO CHARGE ESTIMATED AT ALMOST 2 HOURS.
NOW WORK THAT OUT WITH A 4A CHEAP CHARGER --- equals about 19 hours.
Charging Time
The time it takes tocharge a battery or batteries depends on several things:-
1.the size of the battery charger
2.(CAP = capacity) - the battery capacity in amp hours (Ah)
3.(DOD = depth of discharge in %) how deeply the battery is discharged and
4.(CC = charge current) the rated current output of the charger in amperes
and an approximate charging time calculation may be:-
CAP x DOD CC x 80
For example:-
Xantrexs user manual has a calculation table and lets say you have a Xantrex TrueCharge 40 and
- one battery with a rated capacity of 120 Ah (CAP) and it is 50% discharged (DOD) then the approximate charging time with a TrueCharge 40 would be:-
120 x 50 = 1.875 or say 2 hours 40 x 80
- a battery bank of say 4 batteries in parallel with the rated capacity of 120 Ah each and the battery bank is discharged 50% then the approximate charging time would be:-
(4 x 120) x 50% = 7.5 hours 40 x 80
The above calculation however, is a rough guide only as a bulk or boost charge will go to 75% after which a charger will back off and the next phase will take longer at a lower current until float phase which could take 12-24 hours to do a full top up. It does however, indicate that charging batteries may take considerable time.
My Nipper is parked up at my ex's place, and last week I was heading away for a few days, so asked my son to plug her in to cool down the fridge, and put the battery charger on the in house battery. Which he did.
When I went to turn on a light on the first night, no light.
I had my solar light so it wasn't a problem that night. I also had my solar panel with me.
When the rest of my group arrived the next morning, I just asked if someone could take a look for me. This friends s-i-l told me that my 'normal' battery charger wasn't right for charging a deep cell battery. Is that true?
My brother-in-law had suggested I buy a battery charger some time ago, so I did, and this is the first time I've used it. He didn't tell me to get a specific type of charger though.
I just have a 240v - 12v charger hooked up for charging by 240v and a duel DC-DC Cteck Smartcharger hooked up for all the 12v side of things including the solar panel.
Yes, he checked the fuses first off.
I have a ciggie plug in the van to charge the phone and laptop...laptop has a converter thingy from Jaycar. I've been using that for a couple of years with no problems.
Otherwise, I only have two solar lights, and a couple of torches. The solar panel charges the battery really well, but bil suggested it's a good idea to charge the battery off 240 occasionally to give it a full charge.
This bloke's a bit of a know it all, so I'm not totally believing what he's said until I ask around. I could ring Battery World or other, but thought I'd ask here first.
I have a multimeter, which he used and found it was charging fine once the solar panel was hooked up.
There was no power at this place to try out the battery charger again. It's a brand new charger and son said it was working when he checked on it before I left that morning.
What I'm asking is, does one need a 'special' battery charger for deep cell batteries, or should a regular charger do the job?
No you don't need a special charger for deep cycle, yes a 'regular' charger will do an okay job. There are a few types of deep cycle battery, Gel, Glass Mat, Calcium, 'normal' Wet cell and a few others. Most non deep cycle batteries are wet cells and there is no difference in charging a car wet cell and a deep cycle wet cell.
An intelligent charger (or muliti phase) will do a better job of charging a deep cycle battery than a non intelligent battery charger. Different types of battery have different 'ideal' voltages for charging them. Normal wet cell batteries prefer 14.7V, AGM (glass mat) prefer 14.4V and Gel batteries 14.1V. The multi phase chargers usually start off by slowly charging the battery on a low current, then powering up to high for a while, then slowing down as the battery gets full, then checking that the battery is holding the charge then just drip feeding it until you take it off the charger.
What do you refer to as a "regular charger?" Not all chargers are equal. If you purchased a cheap charger from one of the chain stores it is possible that you have done some damage to your battery. If you can give us some makers names and part numbers of what you have installed we can give some accurate advice and you will not have to read through the usual duff gen that follows from lack of info.
What a lot of people think of as a regular charger is cheap ones from the like of SuperCheap and Big W, The special thing you need is a charger that is tailored to the characteristics of your battery. You need a multi stage charger. I described the workings of a multi stage charger in this thread. Looks like some here did not rad my posting very well.
How can that be? My vehicle motor charges my normal vehicle battery and then when fully charged a relay switches to allow charging the deep cell battery. I understood the only function of the relay was to ensure that current only flowed to the deep cell when the vehicle battery was full. IF this is the case (is it?) then the alternator in the van is a charger for both types of battery.....isn't it??? And we need only one type of charger....????
It looks like I'll have to take a drive out there tomorrow, and get a full description of the charger. It was a fairly cheap one from Supercheap, or maybe Repco. Can't remember which.
Obviously Peter, I didn't know all battery chargers weren't equal. Although I understand that there'd be different qualities, same as everything you buy. When bil suggested I get one, it seems I should have asked questions.
Hold that thought til tomorrow arvo peoples.
We are not talking of alternator charging. This thread is on 240 V AC chargers, a completely different kettle.
Seeing you raised the subject of alternator charging, read http://www.caravanandmotorhomebooks.com/articles/old/the-70percent-debate.html - this is still applicable to the older vehicles. However when you get to the modern vehicles you may find the alternator working at less than 13.8 V which is no sufficient to charge a battery in a van.
-- Edited by PeterD on Saturday 31st of August 2013 03:11:15 PM
Hi Gary
don't need to disconnect to charge, some people do but not nessary
cheers
blaze
Well I didn't get to pick up the charger today, to find out the specifics of it. But I do know it's what I called an 'ordinary' charger, which I now know is called a 'wet' charger. And after doing some googling, which I should have done in the first place, I now have my answer. From here...
http://www.batteriesnorthwest.com/batteryschool.cfm?TID=2
If I'd realised it was going to be so hard to get a simple answer, I'd never have asked in the first place. Thanks anyway guys.
-- Edited by Beth54 on Saturday 31st of August 2013 06:51:56 PM
You do not need to disconect the battery prior to charging, it was suggested in earlier times to disconnect the battery in case the wrong connections were made but now with so many electronic devices on cars etc which forget all their settings when disconnected it it not possible or advisable
So the idea now is to get a new smart charger which also has protection for wrongfull connection.
Hi Beth.
Where you have your van stored is it possible to connect the solar panel and may be position it on the roof and leave it connected till you use the van again, this way the battery will be maintained.
This may save the outlay of a new charger.
That's a thought. Yes I could easily do that. That would certainly save the extra expense.
I only bought the charger because my brother-in-law said it's a good idea to charge the battery on 240 occasionally.
Hi Beth
Although I agree mostly with the link that you supplied, one point may confuse some people
The danger that all batteries face is heat, heat produces explosive gasses and physically damages the construction of the battery.
But most people only have various forms of trickle charges which do not have the power to do damage as the article suggests because it is the current supply and not the voltage which produces the heat and trickle charges which pump out 2 to 4 amps will never be powerful enough to hurt.
As I said in an earlier post it is advisable to get one of the new smart battery chargers to be on the safe side but dont just throw away your good trickle charger to buy a new one for a gel battery
Think of the tassers in use now 50,000 to 400,000 volts and they certainly knock you down but they have minimal current, if you get hit with a bare wire on 230 volts you will die because there is a greater current supply.
Thanks for that extra info Teddy.
I've always just used your generic battery chargers for all my batteries, be it wet cell or SLA. GypsyBob is correct, any charger will do just that, provide charge.
As for the post on dual-battery systems (Nomadicman) - yep the relay is just an automatic switch, which takes your second battery out of circuit once it is deemed fully charged by the said controller. This is so your second battery doesn't get drained when starting the engine or running lights and so on.
So do you think charging it with the solar panel without anything running off it at the time, like lights or whatever, that that would be enough charge without the 240 charge? It's a 80 watt solar panel if that makes any difference.
Beth if the solar panel is connected and left exposed on the roof (maybe tied down so the wind won't blow it off) this will charge and maintain your battery with out any input from the 240vlt charger.
But under the circumstances you have the battery may have been over charged and been damaged and therefore not holding the charge as you have experienced on your last trip.
I would remove the battery and have it checked just to make sure that it is in good working order.
Hi Beth
I think some of the advice you are getting is not appropriate and will not necessarily help you 100%.
I suggect you read PeterD's responses he gave you as he knows what he's talking about and provided some links to assist you. If you read the links it explains things a bit better.
As an example my brothers boat starting battery (wet cell) was always just starting his boat, always just. He used a small charger 4 amps output and left it on charge. However the charger didn't have the "grunt" to overcome the batteries internal resistance and charge it properly.
Eventually he took it to the garage and it took over 24 hours to fully charge it properly,,,staring at 30 amps current,,, his small charger would have never achieved this.
He now uses a multi stage charger to recharge it and he hasn't had a problem for 3 years.
I like examples as they can demonstrate what to some is a simple point but others may not have the experience to understand the tech jargon.
Hope this helps. Baz
I liked PeterD's explanation of the term multi stage charger rather than smart charger, except they are certainly smarter than a trickle charger.
A trickle charger does not have any control it just sends out a charge regardless and in certain cases can overcharge a battery in time.
When you have your battery connected to the car, it's charging system includes a regulator which controls the amount of charge that is sent to the battery and depending on the setting of that regulator will cut out at a prescribed voltage, and obviously the multi stage chargers have a similar function included.
As to a battery that gets very flat, a trickle charger usually does not have the grunt to overcome the sulfurization that occurs to the plates of the battery so a good hard charge is necessary for the battery to recover if it is not too far gone, think of a trickle charger as a machine to keep the battery charged rather than something to make it recover, certainly the non wet batteries do not like being flat at all and will usually never recover
I'm sure PeterD is very knowledgeable, but I'm one of those people who has trouble understanding something technical by reading it. It has to be a simple explanation, or I need to see it done, or a diagram or something. Or, as Baz421 said, an example.
I'll pop out there on the weekend, as I meant to do last weekend, and get one of the blokes to check the battery, get the specifics of it and buy a suitable charger.
Thanks for all your suggestions fellas.
Peter
Beth if he called it a deep "cell" battery I'd be very skeptical of his advice because he doesn't even know the correct terminology! They're deep cycle batteries, and you can use the same charger as for any car battery. (The term "cycle" refers to some of the characteristics of the battery and is important) Though not all chargers are created equal by any means! Get some professional advice if you're uncertain. It shouldn't cost you anything and you'll have peace of mind.
I'm not sure I get the gist of that Peter, but I'll ask 'my' blokes.
Dog lady, I was the one calling it a deep cell battery. I plan to talk to a professional before I buy another charger anyway, but I spoke to my sil yesterday, and he also said the 'normal' charger shouldn't be used. And yes, I'm still calling it a 'normal' battery charger.
OK here's another good section from the web and it's easy to understand,,,, compare this to a cheepie style that has one charge rate ie 4 amps max and tapers off to say 1/2 amp as voltage rises.
From web
For three or four stage chargers you will hear terms such as bulk or boost, absorption, float and storage phases.
Boost phase = is the first stage of the charging process. Essentially it is the stage where the charger puts in as much current it is capable of and as the battery storage voltage increases the charge rate decreases until the battery is about 75% full.
Absorption phase = this is the second stage of the charging process where the charge going in is reduced to about half of the boost rate or a constant rate for several hours (unless a heavy load is drawn and it will then cycle back to the boost stage).
Float phase = at this stage the battery charge is decreased again to about 97% of charge.
Storage phase = or maintenance stage is where there is constant voltage to maintain the battery at full capacity whilst maintaining any DC operating loads.
More info from web. NOTE THE EXAMPLE FOR A SINGLE 120aH BATTERY WITH 40A CHARGER DISCHARGED TO 50% ---- TIME TO CHARGE ESTIMATED AT ALMOST 2 HOURS.
NOW WORK THAT OUT WITH A 4A CHEAP CHARGER --- equals about 19 hours.
Charging Time
The time it takes tocharge a battery or batteries depends on several things:-
1. the size of the battery charger
2. (CAP = capacity) - the battery capacity in amp hours (Ah)
3. (DOD = depth of discharge in %) how deeply the battery is discharged and
4. (CC = charge current) the rated current output of the charger in amperes
and an approximate charging time calculation may be:-
CAP x DOD
CC x 80
For example:-
Xantrexs user manual has a calculation table and lets say you have a Xantrex TrueCharge 40 and
- one battery with a rated capacity of 120 Ah (CAP) and it is 50% discharged (DOD) then the approximate charging time with a TrueCharge 40 would be:-
120 x 50 = 1.875 or say 2 hours
40 x 80
- a battery bank of say 4 batteries in parallel with the rated capacity of 120 Ah each and the battery bank is discharged 50% then the approximate charging time would be:-
(4 x 120) x 50% = 7.5 hours
40 x 80
The above calculation however, is a rough guide only as a bulk or boost charge will go to 75% after which a charger will back off and the next phase will take longer at a lower current until float phase which could take 12-24 hours to do a full top up. It does however, indicate that charging batteries may take considerable time.
Battery State of Charge Voltage Table
