I don't really feel like playing the read-between-the-lines sentence structure semantics game given I clearly pointed out ahead of the amperage value references you are using, as an apparent carte blanche all inclusive justification, to throw whatever amperage anyone wishes at a battery as if input voltage required to do it would be irrelevant to the changing process, which it's not.



I guarantee that when using a constant voltage power source of 15 volts or a bit less for charging a common 12 volt starting or deep cycle battery that is in good working condition but heavily discharged it will reach its charged up point before it gets too hot to do damage. Initial current for the first few to tens of second may be way higher than the recommended continuous charge rating but it won't happen long enough to cook a normal battery.

.

Hi,

Yes and it's good to see that spelled out. But then again for batteries with a max charge current spec i'd want to see the way a higher current affects the battery.

Do you have any data for battery behavior for an LA battery that is charged at a current that is higher than the maximum charge current specification?

 

Do you have any data for battery behavior for an LA battery that is charged at a current that is higher than the maximum charge current specification?

Only personal experience of having done it hundreds of times with common 6 and 12 volt batteries of all sizes and applications.

I've never once saw it as an issue with a known to be good battery. The short time duration of the high inrush current is insignificant in affecting anything.

It's on the same lines as exceeding the C rating of a battery during a momentary overload, like stalling out a cordless tool motor. Not a significant issue given the short time frames involved.

 

Only personal experience of having done it hundreds of times with common 6 and 12 volt batteries of all sizes and applications.

I've never once saw it as an issue with a known to be good battery. The short time duration of the high inrush current is insignificant in affecting anything.

It's on the same lines as exceeding the C rating of a battery during a momentary overload, like stalling out a cordless tool motor. Not a significant issue given the short time frames involved.

Hi,

Well that's interesting. Then why use a high current in the first place if it doesnt actually do much? Do you like that because it is easier to implement then?

Also, i guess we should be looking at the three stage charging method, which i dont really use myself.

BTW, the new drills have overload protection now. My new drill (yeah i finally broke down and bought a new one) has that kind of protection and a super sophisticated charger that's beyond comprehension due to it's complexity.
Most of my 12v LA batteries died so i decided it was time for a new one. Last one was purchased something like 10 years ago so it's very obsolete now.

 

Well that's interesting. Then why use a high current in the first place if it doesnt actually do much? Do you like that because it is easier to implement then?

I am saying 'high current' is relative to the size and state of the battery and the battery is what determines the current draw limit. All of my battery chargers are simple constant voltage units that are set up to top out at ~15 volts in normal mode and are only limited on amperage capacity by either their transformers size or the line resistance of the power source they are fed by.

They do not force a high current through a battery by over voltaging them. They just let the battery take whatever it wants up to the limit that either the batteries own design sets or the limitations of the charger or its power source set.

They are not designed or intended to be left on a battery for days or weeks at a time either as with what a multi stage unit is.

 

Hi,

Well that's interesting. Then why use a high current in the first place if it doesnt actually do much?

The answer to that ties back to what the OP asked, as well as me: This is the chargee we have already, so it's what we want to use, if we can.

 

I am saying 'high current' is relative to the size and state of the battery and the battery is what determines the current draw limit. All of my battery chargers are simple constant voltage units that are set up to top out at ~15 volts in normal mode and are only limited on amperage capacity by either their transformers size or the line resistance of the power source they are fed by.

They do not force a high current through a battery by over voltaging them. They just let the battery take whatever it wants up to the limit that either the batteries own design sets or the limitations of the charger or its power source set.

They are not designed or intended to be left on a battery for days or weeks at a time either as with what a multi stage unit is.

Hi,

Oh ok now we are getting down to the brass tacks

So you do not implement current limit. I hate to sound sarcastic, but "good luck with that"
I guess i am not one for taking chances so i always implement some kind of current limit or current cutout. Too many bad stories about batteries that are being charged, which is the time when most cause a problem.

I do mine with constant voltage more or less, but with an acceptable current limit just in case.

 

So you do not implement current limit. I hate to sound sarcastic, but "good luck with that"

Been doing to for 30+ years now and never had a problem with it on a good battery and I have done it to hundreds of batteries now which puts it well below my concerns threshold level.

 

Been doing to for 30+ years now and never had a problem with it on a good battery and I have done it to hundreds of batteries now which puts it well below my concerns threshold level.

Hi,

Wow, hundreds of amps, hundreds of batteries.

I wish you the best of luck with your future designs.

 

Hi,

Wow, hundreds of amps, hundreds of batteries.

I wish you the best of luck with your future designs.

Not always hundreds of amps in every battery. Most smaller batteries will only pull a few tens of amps. They just take what they want or up to the limits the charger I am using is capable of.

What future designs of what?

 

Not always hundreds of amps in every battery. Most smaller batteries will only pull a few tens of amps. They just take what they want or up to the limits the charger I am using is capable of.

What future designs of what?

Hi,

Ohhh, so there is a current limit then. You said there was no current limit to speak of.
That's safer then none at all.

Future designs of anything you want to do.

 

Ohhh, so there is a current limit then. You said there was no current limit to speak of.
That's safer then none at all.

Really? I pointed that out some posts back.

Are you trolling me or is english a second language because at this point that's the only two rational options I can come up with, without directly insulting you, for not following what I have stated quite clearly more than once now.

 

Really? I pointed that out some posts back.

Are you trolling me or is english a second language because at this point that's the only two rational options I can come up with, without directly insulting you, for not following what I have stated quite clearly more than once now.

Hi,

Oh well you said "hundreds of amps" and that does not sound like current limit to me. How is that current limit?
From what you were saying it sounds like you do not implement current limit by design. You implement voltage limit that's all and hope for the best, at least that is what it sounded like in your previous posts.

START QUOTE
I am saying 'high current' is relative to the size and state of the battery and the battery is what determines the current draw limit. All of my battery chargers are simple constant voltage units that are set up to top out at ~15 volts in normal mode and are only limited on amperage capacity by either their transformers size or the line resistance of the power source they are fed by.
END QUOTE

That's not current limit by design, that is current limit by the hope that it does not draw any more current than it 'needs'. If you dont know the difference i dont know what else to say here. This and "hundreds of amps" say that there is no current limit.
Keep in mind that it is always up to you how you want to design something. I can not force you to implement anything you dont want to.

But now every time you reply you add something new to the specification that you did not mention beforehand. If you are going to do that then you are going to mislead the readers.

But again in the end i dont want to tell you how to do your own circuits. I have recommendations i can speak of that's all. No trolling from this end, just suggestions.

 

But now every time you reply you add something new to the specification that you did not mention beforehand. If you are going to do that then you are going to mislead the readers.

You're just playing a game of never ending nitpicking semantics now so I'm done here.

 

You're just playing a game of never ending nitpicking semantics now so I'm done here.

Hi,

Ok, sorry you feel that way, but then good luck to you.

 

There is a ton of misinformation on here I felt i need to chime in. First and foremost I am not a battery engineer or expert on this matter. I do however work for a car dealership and can say from first hand experience and training that most modern car batteries are designed for high load demands, especially these days as cars come with more and more electronics.

Our manufacturer specified charging equipment charges at up to 80A. For flashing modules/EPROM software some manufacturers like BMW for example require a minimum 45A power supply to the battery, anything less will result in bricked modules. Car manufacturers wouldn't risk millions in warranty claims if these batteries weren't capable of such charge rates.

For home use 10-15A is probably the safest most ideal rate but providing higher current won't hurt your battery either. Constantly discharging and then charging it kills car batteries more than anything.

 

Yes maximum should only be about 20A and that isn't all that good, over time it will damage your battery... The slower the charge the better on the battery. I charge my battery's around 3A then again I'm not drawing off the battery while it's charging. But an alternator which your basically changing out for your charger puts out 50A to 100A so to use it while your drawing power probably not all that bad but if you leave it like that without your sound system on will hurt your battery fairly quickly

 

Hello, I am an employee of Century Batteries - we manufacture lead-acid batteries for the Australian market. I came across this thread and wanted to add an easy to follow battery charging rule which we always recommend to our customers.

First, you'll need to determine the ampere hour (Ah) rating of the battery - it'll either be specified on the top of the battery or you should be able to find it on the manufacturer's website. For example, a typical medium size car battery is around 60Ah.

The charge rate for regular flooded lead-acid batteries is 10% of the Ah rating. So 10% of 60Ah = 6 amps.
The charge rate for AGM and GEL batteries can be increased to 20% of the Ah rating.

Hope this helps!

 

Welcome to AAC!

First, you'll need to determine the ampere hour (Ah) rating of the battery - it'll either be specified on the top of the battery or you should be able to find it on the manufacturer's website. For example, a typical medium size car battery is around 60Ah.

Our car batteries are rated in CCA. How does that relate to Ah?

 

Welcome to AAC!
Our car batteries are rated in CCA. How does that relate to Ah?

Ours are rated in CCA too, but manufacturers also list Ah ratings in our experience. Unless things are different in your country!

 

Ours are rated in CCA too, but manufacturers also list Ah ratings in our experience. Unless things are different in your country!

I just checked autozone.com and they only give CCA, CA, and reserve capacity.