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FNQCairns
09-02-2008, 02:29 PM
I bought a new lead acid battery 6 weeks ago and gave it a charge then a trickle until it was full on the LED lights on the charger but didn't check what it was with the multimeter at the time.

Just checked it's charge and it is currently at 12.1V, the battery has never been used or connected to anything and has done nothing but sit in it's box under the centre console for this entire time as a backup.

Is this a typical discharge rate for a lead acid battery? anyone know the rule of thumb?

thanks fnq

station-rat
09-02-2008, 02:50 PM
Hydrometer (calibrated to electrolite temperature)will give you a very accurate measure of the charge

FNQCairns
09-02-2008, 06:54 PM
Thanks S-R, was wondering if the charge left in it was typical, did some searches and come across this interesting table, looks like the lead acids loose more over time than I thought, mine is OK it seems.

http://www.madkatz.com/ev/batteryTechnologyComparison.html

cheers fnq

Spaniard_King
09-02-2008, 07:20 PM
fnq,

did you know its bad for a lead acid battery to sit on the ground.. especially concrete, a residual voltage of over 12V is acceptable. Your voltage is the what I find most batteries hang at :)

station-rat
09-02-2008, 09:06 PM
FNQCairns
All I was getting at was that the battery may not be fully charged, as some battery chargers cut off well before a full charge is reached

FNQCairns
09-02-2008, 09:29 PM
Yeah no worries S-R mine is an ultra low tech manual charger, I know I should use a Hydrometer to take away the uncertainty over what is actually going on and you are right, even right now this battery is not behaving quite like it should under charge compared to my other older one.

cheers fnq

Simmo2
09-02-2008, 11:55 PM
fnq,

did you know its bad for a lead acid battery to sit on the ground.. especially concrete,

Why is this?

Fed
10-02-2008, 09:05 AM
If you're working on losing 20% per Month then your 12.1 Volts doesn't quite add up.
Here's some Voltage Vs Charge numbers that seem to be fairly well accepted.

100% 12.7 Volts
75% 12.4 Volts
50% 12.2 Volts
25% 12.0 Volts
0% 11.9 Volts

I'm not so sure about measuring the open circuit Voltage of batteries to work out the remaining charge but a lot of people seem to rely on it.
I've seen plenty of batteries read 12+ Volts then drop their bundle as soon as a load is applied.

station-rat
10-02-2008, 09:14 AM
I would agree with FED Specific Gravity is the only way, but have seen batteries that charge and read 100% and drop their bundle as soon as you apply enough load

FNQCairns
10-02-2008, 09:52 AM
If you're working on losing 20% per Month then your 12.1 Volts doesn't quite add up.
Here's some Voltage Vs Charge numbers that seem to be fairly well accepted.

100% 12.7 Volts
75% 12.4 Volts
50% 12.2 Volts
25% 12.0 Volts
0% 11.9 Volts

I'm not so sure about measuring the open circuit Voltage of batteries to work out the remaining charge but a lot of people seem to rely on it.
I've seen plenty of batteries read 12+ Volts then drop their bundle as soon as a load is applied.

Ok thats interesting thanks, I was assuming incorrectly now it seems the 20% was based on Voltage, will charge this one right up let it sit for a day then see what happens using the multimeter.

cheers fnq

FNQCairns
10-02-2008, 01:36 PM
On face value if a battery has been charging until 13V straight off the cahrger but just before disconnecting the charger all of the cells are gassing well except one which is bubbling away at 1/3 or less compared to the others, should this raise an eyebrow?

thanks fnq

station-rat
10-02-2008, 01:46 PM
It would pay to do a few test on that cell compared to the others

FNQCairns
10-02-2008, 01:54 PM
Thanks s-r, will take it back for them to check out, it is brand new afterall.

cheers fnq

Dignity
10-02-2008, 03:30 PM
On face value if a battery has been charging until 13V straight off the cahrger but just before disconnecting the charger all of the cells are gassing well except one which is bubbling away at 1/3 or less compared to the others, should this raise an eyebrow?

thanks fnq

FNQ Thanks for the link - found it useful - that cell bubbling away is going to drop the bundle when you put the load on it. Used to play with model aircraft and used batteries that had dropped a cell as they were free to get. Only need 2 volts to get the glow plug glowing. What we used to do is hammer a nail into each cell and run our supply between the nail and the negative terminal, soon found the dead cell. S-R Where does one get a hydrometer that is calibrated against the temperature as I would be interested in something like that.

station-rat
10-02-2008, 06:14 PM
All hydrometers should be marked with the temp that they are calibrated at, if there not don't buy it

TheRealAndy
10-02-2008, 08:16 PM
fnq,

did you know its bad for a lead acid battery to sit on the ground.. especially concrete, a residual voltage of over 12V is acceptable. Your voltage is the what I find most batteries hang at :)

What a load of rubbish. Concrete makes not difference to any other material. If you look at big battery instalations you will find that they sit on concrete tubs designed to contain any acid spills if a case splits.

Spaniard_King
10-02-2008, 08:30 PM
I suppose your an expert on Batteries hey Andy :P

Simmo2
10-02-2008, 09:39 PM
Quote:
Originally Posted by Spaniard_King http://www.ausfish.com.au/vforum/images/buttons/viewpost.gif (http://www.ausfish.com.au/vforum/showthread.php?p=762612#post762612)
fnq,

did you know its bad for a lead acid battery to sit on the ground.. especially concrete,

Why is this?

Can I ask WHY???
I have heard this before and can find NO evidence to support the theory?? It seems that (from my research) it may well be better for the battery?

station-rat
11-02-2008, 09:06 AM
This is from Rainbow Power Company
All lead-acid batteries will naturally self discharge. The rate of self discharge is most influenced by the temperature of the battery's electrolyte and the chemistry of the plates. Some experts believe that storing car or deep cycle batteries on a colder concrete floor might actually slow down the self discharge (leakage) rate because the floor acts as a heat sink and cools the battery.
In the early 1900s, when battery cases were made of porous materials such as tar-lined wood boxes, storing batteries on concrete floor would accelerate their natural self discharge. Modern battery cases are made of polypropylene or hard rubber. These cases are sealed better, so external leakage-causing discharge is no longer a problem, provided the top of the battery is clean and free from wet or dried electrolyte and the same temperature as the floor.
Large differences in temperature could cause electrolyte stratification within very large batteries (>250 AH) which could accelerate it's internal "leakage" or self discharge if the battery is sitting on an extremely cold concrete, stone or steel floor in a warm room, boat or submarine. Stirrers or bubblers are often used on these types of large batteries to keep the electrolyte from stratifying.

oldboot
11-02-2008, 11:19 AM
In practical terms the batteries on the ground causing discharge it rubbish.

As Mr rainbow says it might have been a problem with very old battery case materials that we havnt seen for many decades.
It may be a problem in very cold locations & then not truly a discharge problem rather a temperature/performance problem.

And it may be a problem in very large cells that we are unlikly to encounter in recreational boating.

Putting battery on the ground or on the cement in our situations particularly in our climate (the frozen south excluded) is not going to make a blind bit of difference.....it may even marginaly help by keeping the battery cool.

There are a lot more significant and proven things you can do to look after your battery.

Back on the subject
One of the most commonly ignored and not considered facts is that ALL rechargable batteries self discharge at a significant rate....and the older they get the worse it gets......unless the battery is mismanaged, damaged or of faulty manufacture, this increase with age of self discharge will be the cause of the battery being not servicable.

There are all sorts of figures published concerning voltages and other stuff about batteries..........It must be understood that batteries are not a close tolerance device.....characteristics will vary from one battery to another and in the same battery over its life..... even from cell to cell within the same battery.
It is not unreasonable to have one or more cells charge faster & therefore gass more or earlier than others.
this is why hydrometer is best ( if you can be bothered) and never rely on the reading of one cell for an indication of condition.

It is unreasonable to expect an accurate "measurement" of the energy stored in a given battery at a given time..... because it will vary from battery to battery, with temperature (especilay) and over the life of the battery.

there are several ways of testing the APPROXIMATE condition of a battery, problay the most convienient is a tong tester....(they generaly have clips not tongs these days)....that loads the battery and gives an indication of its ability to deliver under load.....this gives a one time reasonable assessment of battery condition.... because along with the increase in self discharge the internal resistance will increase with age.
tong testers are a lot cheaper than they once were......the poor mans version is to measure the voltage then turn on the headlights( or whatever) and measure again....or even measure voltage while cranking....... but you have to know waht a similar good new battery would look like in the same situation.

To the inexperienced the voltages in the above tests may seem terminal as the voltages may drop considerably.

enough for now.

cheers

FNQCairns
11-02-2008, 03:10 PM
Too it back and they say it tested good then I made them justify why they thought that(I can be like that) anyway made him go get the special temperature compensated hydrometer even then they put it on the special machin that winds the volts up and reads a costant load in real time think it was sitting happily at 25amps after 5 min...anyway I believe them, we came to the conclusion that my charger is usually charging the same size but older batterys and they due to age take less work and the charger is struggling a little with this new battery to get it topped off...works for me.

Interesting stuff and I now have faith in the battery good enough to go in the boat.

Thanks for the help above esp s-r with that .doc was a great tool for understanding this stuff better.

cheers fnq

TheRealAndy
11-02-2008, 06:35 PM
I suppose your an expert on Batteries hey Andy :P

Had a bit to do with them over the years!

driveon
11-02-2008, 10:55 PM
Hi FNQCairns, somewhere in this thread it was mentioned that the charger was putting out 13 volts, if this is the case then your battery is never going to be charged much over 12 volts.

All automotive type batteries require a charging voltage of around 1 full volt more than the batteries full charge voltage, in other words, as an automotive battery is fully charged at 12.7 to 12.8 volts, the minimum voltage that can achieve a full charge is 13.8 volt.

Put crudely, all automotive batteries are charge by causing a chemical reaction to take place inside the battery. This chemical reaction only occurs at full strength when there is a charge voltage of at least one volt higher than the batteries State of Charge ( the battery’s internal voltage level).

If your charger is only putting out 13 volts, this is why your battery is at 12.1 and as your battery is holding 12.1 volts then your battery is doing very well.

The problem is that at 12.1 volts, your battery is only just over 50% charged.

If I were in your position, I would try borrowing someone else's charger and seeing if this gets the battery to full charge.

driveon
11-02-2008, 11:12 PM
By the way, State of Charge ( SoC ) voltages are as follows

100% = 12.7

90% = 12.5

80% = 12.42

70% = 12.32

60% = 12.2

50% = 12.06

40% = 11.9

30% = 11.75

20% = 11.58

10% = 11.31

0% = 10.5

TheRealAndy
12-02-2008, 06:42 AM
Hi FNQCairns, somewhere in this thread it was mentioned that the charger was putting out 13 volts, if this is the case then your battery is never going to be charged much over 12 volts.

All automotive type batteries require a charging voltage of around 1 full volt more than the batteries full charge voltage, in other words, as an automotive battery is fully charged at 12.7 to 12.8 volts, the minimum voltage that can achieve a full charge is 13.8 volt.

Put crudely, all automotive batteries are charge by causing a chemical reaction to take place inside the battery. This chemical reaction only occurs at full strength when there is a charge voltage of at least one volt higher than the batteries State of Charge ( the battery’s internal voltage level).

If your charger is only putting out 13 volts, this is why your battery is at 12.1 and as your battery is holding 12.1 volts then your battery is doing very well.

The problem is that at 12.1 volts, your battery is only just over 50% charged.

If I were in your position, I would try borrowing someone else's charger and seeing if this gets the battery to full charge.

IT could be 13volts if its in a constant current mode.

oldboot
12-02-2008, 12:11 PM
He actulay states that the battery "measured 13 volts tsraight off the charger"....... and that the battery was gassing prior to being disconnected.

sound like it was fully charged or close to.

I've seen a number of different state of charge figures....... it has to be understood that they are an approximate guide to condition.
not an absolute and accurate measurement of condition.

the figure that drive on quotes sound to me to be very close to the money for unladen figures. with the expectation that the battery isn't unusulay hot or cold and that it has been rested before measurement.

cheers

oldboot
12-02-2008, 12:22 PM
It must also be said that lead acid batteries do not like being deep cycled...... even the so called deep cycle batteries mearly tolerate being deep cycled better.

most manufacturers and writers will recomend not cycling below 50% charge as a regular thing for normal batteries.

most clever electronics with battery protection will cut out at 10.5 volts or higher..... bear in mind that cut out will be under load so the resting voltage will be higher.



cheers

driveon
12-02-2008, 01:48 PM
IT could be 13volts if its in a constant current mode.

Hi TheRealAndy, Yes it could as with a multi stage charger, the charge voltage will drop to something like 13 volts once the battery has reached around a 95% State of Charge ( SoC ) and the lower voltage will keep the battery from self discharging but unless the battery’s SoC is below 12 volts in the first place, this maintenance voltage ( 13v ) will not be capable of raising the battery’s SoC much above about 12 volts.

Cheers.

oldboot
12-02-2008, 08:41 PM
As he stated that the voltage quoted was taken with the battery disconnected from the charger.......... it is purely academic.


however if the battery was in the early stages of a current limited/ constant voltage charge, from a low state of charge...... the charger terminal voltage of the charger may be reduced by the current limiting feature.....in that situation the charger will be delivering maximum charging current and will be charging effectivly.....

it is unlikly that a multistage charger would reduce its terminal voltage at the end of charge as float charge is considered somewhere between 13.5 & 14 volts...typiclay 13.8 volts.

but all this is purely hypothectical.


cheers

driveon
12-02-2008, 11:24 PM
Hi folks, the link bellow is to a fairly useful battery info site.

Most of the data is a generalised nature but it is a good reference site

http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery%20Charging

FNQCairns
13-02-2008, 08:41 AM
After 15h on the 8amp charger I let the battery sit for the last 24h and now have 12.2V on the garmin GPS and much the same on the analogue multimeter (it's hard to tell exactly).

So thats around 60% full :( brand new battery:( do I need a new charger or in the real world is this what I can expect and should live just live with it?

I am starting to understand why I more often opted for a bigger battery than I thought I would needed, but didn't think I should have near doubled the capacity each time:o

cheers fnq

station-rat
13-02-2008, 09:17 AM
Go any buy a hydrometer---$5.00 Then charge it until the hydrometer say it is at 100%

driveon
13-02-2008, 09:24 AM
Hi FNQCairns, put your battery back on the charger for a few hour ( or more ), then before you turn the charger off or disconnect the battery, see what the voltage is at the battery terminals.

If your charger is a single stage type and working properly and it sounds like it could be the problem, not the battery, the volts at the battery should be 13.8 or higher then this would indicate that the battery is not holding a charge but if the voltage at the battery is less than 13.8 then there is a good chance your charger is not working properly.

Cheers

Fed
13-02-2008, 11:59 AM
You could fit the battery into your car and go for a nice relaxing drive.

Just out of interest below is the specs for my car alternator. (Falcon)

Make- Mitsubishi
Rated output- 110 Amps
Regulator- Integral
Regulated Voltage- 14.1--14.7 Volts at 2500-3000 RPM and 5 amps output.

I'm taking that to mean the alternator can push out 110 Amps and not the 5 Amps mentioned, this would make sense because a normal running drain on a car battery would be well in excess of 5 Amps and if the charging rate was limited to just 5 Amps then all our car batteries would be slowly running down.

I'm thinking once you get it charged right up then your little charger will be OK to keep it topped up.

driveon
13-02-2008, 01:41 PM
Hi Fed, thats not a bad idea about trying some other means to charge the battery but the 8 amp charger is not small. It’s suitable for charging up to a 200 A/H battery and this is why I suspect the charger as the problem.

Cheers

FNQCairns
13-02-2008, 02:29 PM
Thanks fella's for hanging with this, in the last 5 days the battery has been on the charger for 30+h, I took your advice driveon and connected it back up again before 10am to do the test then read Feds reply so have kept charging and it might be working I have 13.9-14V while charging when I checked just then and the 100% LED is starting to dim the 75% is completly out now so possibly this battery just needs to be charged a loooong time to get up there where it should be. Will keep going to see if I can get the LED to go out then let is sit for 24h again and take a V reading.

Been chasing up the specs on my charger and cannot find any but did find some that are almost the same unit and they seem to state around a 4.4 Amp constant rate when in the 8 amp mode:( so that could be part of the reason?

If I do get it to charge to 80%+ now and when it gets back to 12.2 after use each time is it OK to re-charge for such a long time, possibly like over 30h straight??

Will be getting a hydrometer also very soon s-r and nail that part, Whitworths has them on a good special ATM.

thanks fnq

PS just checked again while charging and the charger voltage is starting to increase now near 14.2-.3 :-/.

Black magic happening:)

driveon
13-02-2008, 03:09 PM
If I do get it to charge to 80%+ now and when it gets back to 12.2 after use each time is it OK to re-charge for such a long time, possibly like over 30h straight??

Hi again FNQ, if your charger is a single stage type then you will have to keep an eye on it while it charges and as soon as the battery is fully charged, disconnect it.

If your charger is a multi stage charger then you can just leave your battery connected all the time the battery is not in use.

Cheers.

oldboot
13-02-2008, 03:41 PM
OK FNQ...... we are starting to get well away from generalisations...... to make any further sensible comment we need to know some secifics.

firstly
tell us about this battery.
what specific type is it.

what is the aproximate amp/hour rating.

this charger....what sort of chargere is it.
what is its maximum continuous charge current.


if it's a common or garden charger, what is the open circuit terminal voltage.

Personlay I think you are getting more worried than you need to be.

Is the charger capable of bringing the battery up to the point of gassing on all cells wthin 12 to 24 hours.

Unless the charger is a modern and decent multi stage charger with a float charge function...or simply a charger with a terminal voltage of 13.2 to 13.9 volts it isn't a good idea to leave the battery on charge for long periods.

If you are trying to read these voltage off a relativly cheap analogue mulitmeter....you are kidding yourself.....get out a buy even a digital meter, half decent ones are cheap as chips thes days.

the voltage function on your in boat electronics may be giving you an inaccurate measurement........it may be giving you an accurate measurement inside the unit but there may be errors due to length of cable.

Do Not expect to get 100% capacity out of your battery......remember what I said about a battery not being a precision device.

make some reasonably accurate measurements at the batterey terminals with a meter that CAN give you an accurate reading.

It sounds to me like the battery IS charghing to what is reasonable, and I think you are getting a bit carried away with concern.

Yes I do think you may be able to do better buy getting a decent high capacity multistage charger...... but don't lose sleep over it.


OH.... BTW..... how many charge cycles has this battery been thru......I have seen it many times where new batteries dont settle till they have had a couple of cycles after storage.........again this may be another minor issue.

here's a couple of brpoad brush concepts

If the battery is a standard car battery size & shape thing (40 to 55 amp hour), an 8 amp charger should charge it from a low state of charge to a reasonable state of charge over the period of a day 12 hours, should be well and truly enough
If the battery is truck battery proportions....90 to 120 amp hour, the same charger should do it in 24 hours, no problems.

If it is a common domestic type car charger that puts out 4 to 5 amps ringing wett. double that.

Fundamentlay lead acid batteries arent a high performance product......if you expect to get more than.... um......basic performance.....you need to be speding decent money on the gear you use to look after it and be able to continuoulsy supervise the battery and take accurate measurements.

cheers

FNQCairns
13-02-2008, 04:52 PM
Gee oldboot you are testing me here:) going to fail on a few counts though! battery is a generic brand 600cca (forget amp hour now) flooded lead acid, not low maintenance, n70 typical 4wd/light truck battery.

Brand new never used, unitl monday when they load tested it for 3-5min wound up to 14.7V.

Charger is a manual type Arlec 8 6/12V, 2/8 amp, cannot find it's specs seems discontinued, other like chargers seem to spec around 4.4 amp constant on their 8amp chargers. Open circuit V - I have no idea what or how! it was a good (in price anyway) domestic charger when purchsed.

The multimeter cost me $100 10 or so years ago, dunno the true quality though, it's another Arlec.

I have near 0 V drop over the boat power circuit and both the Garmin and Furuno give near nil variance same as the multimeter when compared to them I am confident to with most readings over the 3 units but do have a little trouble with the analogue getting it within a volt.

No not looking for 100% out of the battery would like to see 80%+ change after 24h off the charger seems I am getting not much better than 50% ATM.

Lead acid so far has been the best bang for my buck over time will stick with them until some technology with a decent warrenty to back up their claims and my time comes along, will stick with the charger also unless I can prove it faulty, suspecting this is a borderline quality battery and like you say it has not been cycled yet, so far my other slightly bigger batterys in capacity that have only ever known this charger and the boat/4wd are 4 and 2yo and they charge higher it seems than this new battery:( but this time around the new one has been hogging the charger a fair bit so cannot say for sure.

Will keep charging this battery overnight, the charger is getting warm now...unless I am gassing it for too long overall, what is too long trying to reach a fair level re-charge.

Yeah I could be getting too conserned, I am less so now than earlier, although it would be nice to find out what is not quite right or is this normal of sales speak and marketing and I should I expect it as typical?

Regardless an interesting journey so far, the bloody volts have dropped at the charger again back to 14:(

cheers fnq

driveon
13-02-2008, 05:37 PM
Regardless an interesting journey so far, the bloody volts have dropped at the charger again back to 14:(

cheers fnq

FNQ, 14v is fine.

As long as it stays over 13.7, you will be charging the battery if the battery is OK and it sounds like it is, it just needs a good charge.

You will still probably get some gassing while charging, don’t worry about it, you can always top up with water after you have finished charging.

Cheers

oldboot
13-02-2008, 06:05 PM
Ok
this sounds like the old "Charger 8" if you've had it for some time.
it will be a typical domestic automotive charger & should have a charging voltage of arround 14 to 15 volts.....;D ....you say it has a string of LED's on it....... it might be a bit more recent.

either way these things are pretty rude.....they will probly be no regulation of any sort in there, just a tranny and a rectifier...... so you cant depend on the voltage being all that stable.


check that the wires where they connect to the clips are making good connection.
these units are better with some better clips too.

Most certainly not a good idea to leave a battery on such a charger long term.

At the moment your best investment would be a decent multi stage charger of at least 10 amps capacity.

Multimeters have plumeted in price and improved in quality in the past few years.
I just baught the fatherinlaw an new meter.... cost me a bit over 20 bucks and wasnt the cheapest I could get bay far......it had better features and accuracy than the AWA ( chung instruments ) unit he was issued with on the ship.

Stick with lead common lead acid...... yeh I recon so.

It is possible that your charger is struggling to deliver sufficient current to make a quick job of it.

check the open circuit terminal voltage of the charger.
then check the battery terminal voltage with the charger connected.
If the charger is pushing 15 volts or so open circuit and only 13 or so on the battery, it is still trying but not got the job done.
Sounds like the battery would be about 70...80 amp hour.
If the charger is only delivering 4 amps maximum charge ( it would have to be better than that) it is going to struggle charging that battery in under two days.
It may even struggle to get a full charge at all......not good.
Even when " fully charged" a battery of that size will still be sucking about 1.5 to 2 amps out of a standard auto charger and just disapating it in heat and bubbles.

Most will argue that you want to get a battery up to charge quickly rather than slowly stewing it.....and then switch to a float charge.
It seems to be the neither here not there charge rate that is looked down on particularly by those who are strongly out against sulphation.

One of the most important things I recon on a battery charger is an ammeter....it shows you whats going on.

yep.... a new charger I think.

cheers

FNQCairns
13-02-2008, 06:47 PM
Hi Driveon more shopping! I need water too!!:) and a hydrometer, new multimeter and possibly a U beaut charger...crikey!

Thanks Oldboot, if open circuit means leaving the charger on then reading the V from the dangling clips I got 11V, tried twice. What does that say? I also checked V just before the clips and there is no drop, interestingly if I switch it to the 2 amp trickle the LEDs tell me by not lighting up at all that it doesn't need it?

What brand was the multimeter you purchased? would be nice to have a digital version that was acurate.

There is an Ac delco 4 stage 15amp charger in the supercheap catalogue for $199 sounds like a deal? anyone? Doesn't seem to have an amp meter but.

Thanks fnq

driveon
13-02-2008, 07:18 PM
Hi FNQ, personally, I wouldn’t touch Arlec with a barge pole.

You only need a 4 amp charger but if you want to go bigger it won’t hurt anything other than your pocket.

BTW most battery manufacturers recommend a low charge current rate as being the best way to charge their batteries.

Try to get either a 2 stage or a 3 stage charger so that you can just leave the battery connected to the charger all the time without having to keep checking the state of the battery.

Cheers

TheRealAndy
13-02-2008, 08:41 PM
Measuring the output of the arlec with you multimeter will not help a single bit. The output of the arlec charger will be rectified AC, which probaby means nothing to most, but more or less will give you a lower reading. I will not go into detail here (unless requested), but suffice to say the charger output means nothing.

If you can afford to buy the AC delco charger, then do it. Hopefully it will have a light on it to say its in float mode, if it does not then forget it and buy something that does. Even with a 15A charger expect to wait 24hours or more for the battery to fully charge.

BTW: Hydrometer is the only way to accuratley mesure battery charge, but I reckon its too much screwing around. If you want a hydrometer reading then take it to a battery shop!

oldboot
13-02-2008, 11:56 PM
Sorry but here we go again.

drive on
show me where a manufacturer of car batteries recomends a low charge rate.

It simply does not reflect reality..... no car or truck charges at a slow rate.
most cars have at least a 40 amp alternator 90 amp isnt unreasonable in a truck or 4WD.

a 4 amp battery charger will take for ever to charge a truck sized battery.
4 amps into 80 amp hours...... thats 20 hours at least... acount for charge tapering and losses it will probly end up taking at least 48 hours to come up to charge properly.

At least 10 amps, 15 or 20 would not be unreasonable to charge any car sized or bigger lead acid battery.

Thanks andy I forgot about the lack of filtering and the error measuring these crude chargers..... dead right it will be quite inaccutate.

check out the marine shops like bias boating & such.
they have some decent chargers too.

I think bias stock the Min Kota charger ( which is quite reasonable in both function & price) and a couple of otheres thet look suspiciously like the ones jaycar import.
The AC delco sounds a reasonable thing...... It sounds a bit dear to me.... but I'm not used to paying retail;D .

An ammeter is less important on a proper multistage charger, because it should know what its doing.... where as otheres you need to keep an eye on them.

I have an old arlec "charger 4" which I've had for over 20 years it will push 5 amps short term......It works & it does a job. but it is a crude charger and it has to be watched like a hawk... I have several other chargers I'm much happier with.

the range of digital multi meters from jaycar are quite reasonable and even the realy cheep ones in their range will do the sort of job you are looking for.

I have an older up market model from jaycar that I have had for ages as a workshop meter......Hey its as good as the fluke I carry in the field, has more features and was less than half the price...... but customers like to see a fluke.

cheers
They also have a very good little book on how to use a multi meter.....very worthwhile for the average bloke.

FNQCairns
14-02-2008, 09:01 AM
Thanks for the replies, have a plan today heading to into town to get this: http://www.jaycar.com.au/productView.asp?ID=QM1526&CATID=&keywords=multimeter&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

it has continuity which I like + temperature also. Will also buy this: http://www.jaycar.com.au/productView.asp?ID=MB3620&CATID=18&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=295
If they let me take it away with the guarantee I can bring it back unopened within the next week and if the warrenty is 2years or more.


then off to here to get this: http://www.whitworths.com.au/main_itemdetail.asp?cat=123&item=4341

and some water.

The end of an era is near!

BTW this is the cahrger I have ATM different branding but same: http://www.jaycar.com.au/productView.asp?ID=MB3522&CATID=18&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=295

Will list my new more scientific results when I get them :D I have just disconnected the battery after another 20h long charge and it has already dropped to 12.5V 30min after:(

cheers fnq

station-rat
14-02-2008, 11:45 AM
A quick check with the hydrometer will tell you how it has been charging
The new gear should set you up for a few years, battery charging wise

oldboot
14-02-2008, 08:49 PM
the multi meter looks very similar to the one I got the fatherinlaw...(there are a few very similar with different features).....I could certainly get by with one of those....not a "status tool" but it will do the job.

I've been eyeing off one of those chargers too...even at retail price they look to be good value.

Yeh I noticed the low price of hydrometers too......If it works at that price why the hell not.


Now you are tooled up:thumbsup: you'll be thinking its christmass or something:bdaycake:

cheers

dnej
14-02-2008, 09:35 PM
http://www.ibsa.com/www_2001/content/about_us/current/december_1999/1199_techtalk.htm

Some more info
David

FNQCairns
15-02-2008, 01:29 PM
Well I did my shopping came home with a different charger though, the Jacar one has only a 1 year warranty, the ACDelco has 3 I understand but need to confirm, there was no warranty info in the box.

I tested the battery before I put it on the ACDelco and it was 1.250 on the hydrometer and 12.6V on the new multi, yet the new charger said it was 12.4V and my old multi 12.3 ish.... sheesh!!!

The new charger I set to 15 amps but the battery sounded like I was cooking sausages inside so I dropped it to 10amp, when switched to the mode for % charged and it said 80%, took 1.5h to actually reach this new full this time and the charger was pumping 14.9v through it at times read from the charger display.

After sitting for 14h now the hydrometer reads 1.285 at 30degC and 12.75V on the new multi.

Will be getting a lend of a mates mulit over the w/e I need just one V reading device to read the same as another, they are all so far out, no idea which one is correct atm.

So thanks for all the help I have now 2 fully charged batterys, the 3year old battery charged higher than my new one, but they are fully charged, yippeee!.

Expensive but with this charger the fuss is gone just set and forget, thats nice change after the old one + it's real fast!

Thanks s-r, driveon and othersfor all the help, it was an expensive exercise but I learnt a some stuff too.

Cheers fnq

station-rat
15-02-2008, 09:09 PM
Sound like you are on the money now FNQCairns

driveon
15-02-2008, 09:43 PM
Well spent dosh FNQ and it’s like having a new range of toys. ;D

Don’t worry to much about minor differences in voltage readings, the important thing is that, even with normal differences, you will still have a fairly good idea of the state of your batteries when you need to know.

You will also get a good understanding of how they work and how you can put them to work.

Have fun mate and keep us informed

FNQCairns
16-02-2008, 08:13 AM
Yeah all is good now, my old battery now has 12.9v after 20h sitting so it is certainly charged up! Think in the past I have thrown a couple of batterys away that this thing would have saved, if it lasts 7-10y I will break even:) butthat doesn't count the ease of use.

Sorry Oldboot missed thanking you, very much help thanks, meant to add in my last post consider looking into the ACdelco there is a seller on ebay that has them for $150.00 +$20 postage and there is a protector 15amp 3stage for $120 which is a right bargin!, dunno where the acdelco sits in the range of brands for experienced buyers though.

cheers fnq

Taroona
16-02-2008, 10:16 PM
Hey go to this link I found lotsa interesting information...

http://www.marine-electronics.net/techarticle/battery_faq/b_faq.htm

.

Dignity
17-02-2008, 10:42 AM
Hey guys, lot of info there and thinking have to go and get myself some new gear if only the weather would improve so that I can use the boat. A couple of questions:
What level should the fluid in a lead acid battery be ie how high above the plates, with all this charging and discharging there must be some loss and I always worried that there is either not enough or too much. I use a couple of paddlepop sticks to measure mine and try to keep the fluid all the same height. Main reason is that to remove the batteries is a major effort and I can't seen the levels through the case.

I try to use distilled water if I do top up, is demineralised ok in emergency situations. I usually carry a bottle with me camping etc although I forgot to label it once and some one emptied it thinking it was plain water. I noticed that the missus brought some distilled water home for the iron so it seems it is easier to get than previously.

driveon
17-02-2008, 12:09 PM
Hi Dignity, you can get distilled water at any grocery store these day, just go to the cleaning products section or the fabric softener section, like your wife did.

Demineralised water is fine to use.

All flooded wet cell batteries have built in maximum fluid level indicators.

When you remove the cap from the cells, there is a plastic indicator sticking down into the cell and you just top up the water until it touches the base of the plastic.

By the way, it doesn’t matter if there is a little more water added to one or two of the cell than is in the others, the important thing here is with flooded wet cell batteries, ALWAYS keep the plates covered.

Cheers

oldboot
17-02-2008, 08:39 PM
the traditional water level is 6mm ot 1/4" above the seperators (thats the top of the pack of flat things you can see down the hole.

As drive on says there are fluid level indicators in every wett battery I've ever seen.
the trick is to look down the hole.......if you just see flat water when you look down you need to top up......as you top up you will see the water form a menuscus (the water will climb the walls a bit) inside the level indicator......once you have seen this it is very obvious.......if you can see the top of the plates:o you need to pay more attention.

the best thing to top up with is the little beaker you get with steam irons.

Demineralised water has pretty well replaced distilled water for most uses these days.........they cant call it distilled because it is filtered by reverse osmosis.
If they are running the RO properly it should be better than distilled any way.

It's the mineral content that is the problem.......

good clean directly collected ( not of an iron roof) rain water should cause no problems........my old man always used to have a "sacred bucket" he used to put out to collect rain water for batteries and such......after it had been raining properly for half an hour or so..... out would go "the bucket".

cheers

BaitThrower
22-02-2008, 09:54 PM
FWIW I just charged up my 18Ah AGM battery and checked with my multimeter. Straight after charge it read 13.2V. 30 minutes later, 12.9v. Will check again tomorrow and see how much further it drops.

Dignity
25-02-2008, 08:06 PM
Thanks guys, I had a look and neither of my batteries reached the plastic tube. I checked the cars and the same. As mentioned it is difficult to remove my batteries in the boat and almost impossible to look down. I have tried a mirror but not clear at what I am looking at so the thought was to remove the battery, find the optimal level and use a dip stick to check at a later date.

Simmo2
25-02-2008, 09:33 PM
Don't forget Dignity, even tho you put water in the battery, when you pull the dipstick out it will be acidic! Don't put the lolly stick in ya mouth whilst opening the next cell!!

Dignity
01-03-2008, 09:20 AM
Don't forget Dignity, even tho you put water in the battery, when you pull the dipstick out it will be acidic! Don't put the lolly stick in ya mouth whilst opening the next cell!!

mmm - wondered what that tingly taste was.