Battery Charger

IMO, Yes, a very large one. Say a electrolyte type of capacitor.

But somewhat special.

I'm agree but ripple still the high ?

Indeed, with certain cheap chargers you can hear the ripple on the radio while charging. That is one of the specific differences with most capacitors. It has to do with the electrolyte and the plates. A capacitor that size should have a far far bigger dielectricum and larger surfaces. That is why it takes time to charge a battery and certain limitations in charging current may apply. A battery needs time to adopt its full charge.

Ripple is OK for flooded batteries; Less than 3% ripple compulsory for VRLA batteries.

What are VRLA batteries ?

Do you mean Sealed batteries ?

"Less than 3% ripple compulsory for VRLA batteries"

VRLA(AGM)batteries have much less internal resistance than flooded batteries ,so ripple has no problem with VRLA batteries.

This will help understanding ripple effect:

http://www.google.co.in/url?q=http://www.battcon.com/PapersFinal2007/CantorPaper2007.pdf&sa=U&ei=-f_hTN6VDoPsuAOw4K2pDg&ved=0CCIQFjAH&usg=AFQjCNECOloRg4Qa2h8BsIQdeKN61y88JQ

http://www.google.co.in/url?q=http://www.digatron.com/fileadmin/content/PDF/VRLAmanual.pdf&sa=U&ei=-f_hTN6VDoPsuAOw4K2pDg&ved=0CBwQFjAG&usg=AFQjCNH9P5vhnl7DAVvRKHzM1oHn0pJmzg

sorry,the second link doesn't open.

Try to post it again.

Thanks

Lot of information on this site: www.digatron.com or type firing circuits on google search.

sorry,this link also doesn't open.

Try to post it again.

Thanks

Yes the link is not working. I got PDF version; give mail ID then I shall forward.

kvsubramanyam@hbl.in

'Ripple doesn't hurt in a battery charger and may even be beneficial.'

How come the ripple can be beneficial for the battery-could you explain please, some people complain about the high ripple in the charging current !

First, why would someone complain about ripple in this application? Second, ripple can help to dislodge gas bubbles that form on the plates.

"why would someone complain about ripple in this application?"

Battery get heated because of ripple.

Battery gets heated by the power dissipated in it. It would arrive at the same temperature if all the ripple was filtered out and the applied voltage was the RMS value of the actual waveform (i.e. .707 times the peak ripple voltage).

May be the ripple only useful as a de-sulfator- but I'm not sure about that.

Well,to make sure about that we have to see if the full-wave rectifier style charger makes the battery lives longer than the high frequency charger(which contains no ripple) or not ?

Does any one have experience about that ?

GA

Totally correct......

<...Battery get heated because of ripple....>

Codswallop.

Total rubbish.

GA

Many feel its very beneficial......I tend to agree fully....

1. = Partly correct for normal LA Batteries only.

2. = Correct for normal LA Batteries only.

3. = Correct for normal LA Batteries only.

4. = Total Rubbish/Codswallop.

4. (Second 4, you can't count correctly!! = Total Rubbish/Codswallop) = normal LA batteries have very little internal resistance when fully charged - as many have found to their cost!!

Question, how do you think that when starting some cars, up to between 200 - 400 amps will be drawn for a few seconds! How would that be possible at 12 volts if the internal resistance was significant????????

If the internal resistance was only 0.5 Ohms for example (considered to be a fairly low resistance normally), the max current would be limited to 24 amps only - simple Ohm's law......I = V/R

Conclusion, the internal resistance of a car sized 12 volt battery, when fully charged is so insignificant as to be almost not worth even thinking about!!

For 400 amps (for example), the resistance cannot be more than 0.03 Ohms in the entire circuit - which (please remember!) also includes the resistance of the starter motor and the connecting cables/chassis.........so the battery is probably several orders of resistance less than that........

Can the ripple in the charging current help to reduce or prevent battery's sulfation -that is important question ?

There are plenty of units and chargers around that "fire" high voltage pulses at LA Batteries (100 volts or more) at preset intervals (that is REAL RIPPLE!!) and believe that sulfating is reduced in a sulfated battery and that sulfating does not start in a "good" battery.

My observations tend to agree with that, but I have no factual evidence to prove or disprove that.

My personal take is that batteries are like muscles, they need to be used again and again eg. trained......these pulses (and ripple) supply the training needed for the battery to stay fit longer.... in my opinion only.....

I advise to conduct an experiment on two similar batteries - i know the experiment will take at least 5 years to get factual results, no matter for me i will wait for the results.