Trickle Charging

Yes.

You answered his question! Now he needs to ask what he really wants.

I went with the others and have GA, on a clearly OT tread!!

Couldn't resist giving you a GA as well

hi,

greetings from India

trickle charging is carried out after full charging of battery.

generally it is 1/100 of full current capacity of battery.

a constant current supply is always provided to battery for maintaining battery in full charged condition.

If nobody had any ideas about this, where would the term "trickle charging" have originated?

Do you dismiss any creative process?;)

Are you kidding? How does that question "dismiss any creative process?" On the contrary, the point is that if anyone dreamed up the term "trickle charging", they must have had some idea about it, which is what the OP asked.

Just humouring, of course... I was just pointing out one could make up a name for something completly fictuous or abstract. You are right they had the idea...

Trickle charging is also referred as Float charging. As we all know that every battery has its own rate of self-discharge. This means that it is kept uncharged or unused for a period, battery will lose its charges.

So, Charging a battery with a rate equal to its rate of self-discharge is termed as Trickle or Float charging.

Vinu_Answers Sure_Answers

This being true, its implementation is very dependent on the battery chemistry used.

In power plants & substations where DC control supply is used for control,protection & signalling circuits of the switchgear ,Float-cum-Boost Chargers alongwith Battery banks are provided to ensure reliability.

These chargers receive 3 phase, 415 V AC supply and give 48,110 or 220 V DC supply as output to the switchgear under normal condition.In case,AC supply to the charger fails ,battery automatically comes into picture in order to meet the requirement .In the process the battery gets drained .

If the restoration of AC supply takes very long time,say more than 4 to 5 hours,the battery has to be boost charged upto its rated parameters immediately after restoration of AC supply.

Under normal operation,the charger operates in float mode delivering DC supply at a voltage, slightly higher than rated voltage of the battery so as to trickle charge the battery, simultaneously catering to the requirement of the switchgear.

The purpose of trickle charging is to keep the battery under healthy condition to enable it to meet the requirement of the switchgear under the exgency of failure of AC supply to the charger.

Hope I am clear.

Too bad you posted off-topic, a clearly good question. Most battery farms must still be lead acid.

GA. There are terminology differences. Trickle charging is essentially constant current charging. If the battery charge is low, the charge rate will be too low and the battery will take along time to receive full charge. After the battery is fully charged, the trickle rate may be too high and the battery life shortened. The newer breed of smart chargers are designed to charge at an optimum rate until the battery is fully charged and then shut off until the charge level drops below a critical level. This way, the battery can not be overcharged. You can leave these chargers connected indefinitely without risk of overcharge.

Yes shut off at a preset level is an option. But how about shutting the mains feeding the transformer and AC-DC converter? It also consumes a good amount of power. The shut off be at the input.Generally it is not so, it is at the output.

Secondly LA battery if cycled at lower level of charge eg 70% as mentioned it will give much shorter life compared to cycling at full charge level. It is characteristics of LA battery. The best option is to go for capacity such that battery is discharged to say upto 50% level max. Otherwise flooded LA battery has a tendency to stratify. Without over charge and bubbling the battery will never attain full charge. For Tubular flooded battery ,the battery can take such abuse and can be charged fully in a better way.

Another input is that peak battery voltage goes down after few months. So an adjustment based on peak voltage will need future adjustments.

So trickle charge is not simple anymore and if one is conscious about implications, energy saving potential is enormous, considering millions of such cases in use.

Yours is a very interesting post, I reproduce it here with my personal, empirical take on the subject (Battery charging is always good for a discussion!! )

Here is your post and my answers in italics:-

Yes shut off at a preset level is an option. But how about shutting the mains feeding the transformer and AC-DC converter? It also consumes a good amount of power. The shut off be at the input.Generally it is not so, it is at the output.

You are so right, I personally use an Opto coupled Triac to switch the mains on and off to the transformer. A very simple method, but has the bad news that a completely empty battery cannot be charged, so I also put in a switch to allow that if needed......though I have never been in that situation either.....

Secondly LA battery if cycled at lower level of charge eg 70% as mentioned it will give much shorter life compared to cycling at full charge level. It is characteristics of LA battery. The best option is to go for capacity such that battery is discharged to say up to 50% level max. Otherwise flooded LA battery has a tendency to stratify. Without over charge and bubbling the battery will never attain full charge. For Tubular flooded battery ,the battery can take such abuse and can be charged fully in a better way.

Firstly I have never (knowingly anyway, had a tubular battery, I don't know if my caravan battery is such or not!).

I disagree about the charging method causing an early battery life failure. In fact I am of the completely opposite opinion as my caravan battery, which is my test battery as well, will shortly be 10 years old, and appears to be going strong. It has already lasted over twice as long as several earlier batteries one of two different commercial caravan chargers. They were not cheap either!!!! Which is where I got interested in designing my own.

Also, I have never met anyone who has charged as I do for many years till a battery fails, it appears to be a well publicized "Old Wives Tale". Have you actually tested this out yourself?

Another input is that peak battery voltage goes down after few months. So an adjustment based on peak voltage will need future adjustments.

True

So trickle charge is not simple anymore and if one is conscious about implications, energy saving potential is enormous, considering millions of such cases in use.

Also True

When you mentioned that you are only charging up to 70% level, and not full charge, it is not good. My knowledge says LA battery if cycled less than full charge level ,it has a much shorter cycle life. Now, since you have got very good life with this arrangement only, it needs additional inputs from experts in this forum.

As far as I (and my battery!!) am aware, that does not relate to LA batteries at all (I do it every day to my LA caravan battery since 2001!), but only to (certain) NICAD Batteries, the so called "memory effect".

It has been extensively documented all over the world, but I feel that its less of a universal NICAD problem than many believe. i never saw it on my portable drills for example, most are NICAD....still!!

I will post the event when I need to replace my caravan battery, but it does not appear that it will be soon....

What is your take on some of the new "battery tender" products which have a programmed varying charge/discharge rate as opposed to trickle charging? I am trying two on my snow blower and SUV at my "up north" home, but it has been under 2 years of use, so I can't comment on effectiveness yet (other than so far so good).

Funnily enough, that is exactly how I design my chargers, as can be read on many CR4 blogs over the last few years......

Thanks for the comments and the GA.

As I wrote, I am not a fan of trickle charging, I believe in charging at a relatively fast rate, but cutting it off before gassing, starting again before sulfation starts.....its really a very simple method....

Not 70%. But cutting before gassing is the answer. Now I know why you have good health !!

Well how do you cut before gassing??

70%......truly!! After that "Gassing!"

You should read more documents from battery manufacturers.......there is so much info on the web....

GA.

This explains why the float charger invention performance at a marina I worked at as a young man was, shall we say, underwhelming!

With, as I recall, more dead batteries in the spring than when we did nothing at all!

Maybe it was a scheme to sell batteries, I don't know!

Thanks for the GA and the interesting comments from your own personal experiences. It fits in well with my experiences and thoughts......

Please tell everyone that I did not pay you to write this!!

GA, great 11000 posts, 113 GA, you deserve this. I work in a battery manufacturing unit and have good knowledge about batteries, chargers, discharges, testers, etc; but still do not have that patient to type so much. You have impressed me with your post!

Does the triac have a diac in front of it?

It can have, some use just a resistor (Diac is better!), some use an AC solid state relay (Triac inside) and a DC voltage......there are many ways.....I tend to use the solid state opto isolated relay as I can switch it using the battery voltage!!......

If I can help further, just ask.

Does it have a quadrac after it, though?

When I was in US Navy (70s) the lead-acid batteries on subs were frequently DISCHARGED at a slow rate, then brought back up to full charge. Of course, there were multiple banks and a lot of redundancy in the equipment.

Note that I served on surface ships, so I rely on memory about this .. but I would guess that a lot of research went into whether to keep batteries fully charged or to "cycle" them through charge/discharge. Maybe someone w/ more recent experience can chime in.

I have many ideas about trickle charging.

I presume you want to hear them.

The name of the process "trickle charging" may mean different things to different people. This can cause a LOT of confusion.

In my battery shop....we did all sorts of charging. Deep discharge, cranking amp tests, fast and slow charging, variable cycle charging and a few others not germane to this discussion.

Trickle charging is not slow charging. In fact, I don't think you could charge a battery from zero to full charge with a trickle charge.

Trickle charging is a small topping up charge, designed to keep the battery fully charged even during long periods where it not being used. Like a car or truck being stored over the winter. Often a solar panel is left on the dashboard to provide a tiny trickle charge. Such solar panels are made for this purpose. Clearly the amperage used in a trickle charge is in the fractions of an amp.

Lead acid batteries like to be fully charged. If they are allowed to run down, even a bit, the spongy lead which makes up their plates will sulphate and flake off, forming a sludge in the bottom. In the winter here in Canada, if you let a battery discharge too much, the H2SO4 will turn into water, which will then freeze, destroying the battery.

Is this helpful? Not really a lot of new information, but perhaps a knowledge of different charge types will prove to be useful in your future studies on this topic. As others have pointed out, there are a lot of variables involved. Batteries will self discharge for a variety of reasons...dirty on the top, humid environment, very hot environments. It may be hard to perfectly match the trickle required to counter the normal self discharge any battery encounters.