Previous in Forum: Percentage of Error in Analog Meter Readings   Next in Forum: Can I Run an Alternator with Electrical Motor?
Close
Close
Close
67 comments
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251

Will this Circuit Allow Correct Battery Charging?

08/01/2010 6:10 PM

I think not.

It will just cause the batteries to be undercharged.

It is a bad circuit in my opinion.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
Pathfinder Tags: Circuit design.
This discussion was "closed" on 08/03/2010 11:48 PM. No new comments are allowed.
Message from admins:
This circuit was taken out of context from another post and is an abuse/attack on another CR4 user. Please review the CR4 Site FAQ and keep things friendly.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20969
Good Answers: 780
#1

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 6:28 PM

Yeah, that looks pretty weird, but for other reasons.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15136
Good Answers: 937
#2

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 6:39 PM

There's not enough information here to say the it won't work but I will say that likely it will work.

If the UPS charge circuitry controls the charge by monitoring the battery charging current (many but not all do) then regardless of the voltage drop across any pair of diodes the correct amount of charge will be placed in the battery. If the UPS monitors the voltage across the battery at the UPS node then the battery may not become fully charged as fast as normal but it will eventually fully charge. In this case, one can likely identify the charge sense components from the charge providing components. Running the sense connection to the battery directly will likely fully restore charging time. Now most UPS driving circuitry are designed to produce full AC power with the battery at 75% output voltage. So in discharge the ammeter and diode drop will again not be significant.

I do see now a small typographical error that might be misunderstood. The leads of the ammeter only connect to the diodes of the bridge. The negative lead of the ammeter is not directly connected to the positive side of the battery. (I do believe that this typo was discussed in the earlier posting.)

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#4
In reply to #2

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 7:16 PM

As far as I can see the charging circuit is 2 times "forward voltage drop" from the batteries and no sign of ....Running the sense connection......which I agree would work wonderfully...sense wires are brilliant for correction of bad circuits like this one and would solve the problem for the question from which this is derived.

For me if the charger is looking at a battery with a volt drop in between in will not charge it correctly.

I mean why by a battery charger and fit 2 diodes at the output ?

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15136
Good Answers: 937
#5
In reply to #4

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 7:29 PM

This post was deleted because it did not adhere to the behavioral policies of the site. Please review Section 14 of the CR4 Site FAQ and the CR4 Rules of Conduct.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply Off Topic (Score 3)
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#6
In reply to #5

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 8:21 PM

It seems as if you you have become confused.

You can not answer my questions and all you can do is give insults.

I do not care about your "forward bias Kirchhoff loop circuits" is is not part of the question.

I have designed and built many battery chargers in real life and tested them I know what would happen to these batteries in this circuit...they would deteriorate at a higher rate than if properly connected.

I defy you to balance a mattress on a bottle of wine in reply to......."I defy you to identify the forward bias Kirchhoff loop circuits for charging and discharging the batteries and the loop equations."...search the Internet if you are lost when it comes to charging a battery !!!!!!!!!!!

The impedance of an inductor can be determined at a given frequency and this would be it's resistance.

Therefore I think it is you who needs some schooling on V=IR if that is what you are referring to.

Inductors have "Q" ratings and this can be expressed as a resistance at a given frequency of supply voltage.

Kirchhoff developed laws which hold true in physics not unlike the law of V=IR !

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 3)
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15136
Good Answers: 937
#8
In reply to #6

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 8:29 PM

I knew it, you do not even know what a Kirchoff loop for nodal analysis is.

__________________
"Don't disturb my circles." translation of Archimedes last words
Register to Reply Score 1 for Off Topic
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#9
In reply to #8

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 8:42 PM

I knew it you could not balance a mattress on a bottle of wine !!!!!!

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 9)
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#3

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 7:02 PM

Have you decided to make this some kind of personal vendetta?

(For anyone who missed it, my drawing was copied from a post in this thread).

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#7
In reply to #3

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 8:25 PM

No.

I just want to point to observers that the circuit is not so good.

It will work as far as the ammeter is concerned but it is not a good circuit for advice.

Nothing personal and I have voted you some "good answers" but I bet you have not voted me some good answers.

Am I correct ?

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 8)
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20969
Good Answers: 780
#18
In reply to #7

Re: Will this circuit allow the batteries to be charged correctly ?

08/01/2010 10:37 PM

Yes, you seem to be correct, not having received any GAs in 130+ posts. Is anyone surprised?

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru

Join Date: Oct 2008
Location: Deepest Darkest Rutherford Oz
Posts: 951
Good Answers: 145
#10

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 8:49 PM

Short answer is no.

__________________
There are two reasons for a man to do a thing, One that sounds good, and the real one...
Register to Reply
Guru

Join Date: Oct 2008
Location: Deepest Darkest Rutherford Oz
Posts: 951
Good Answers: 145
#11

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 9:00 PM

There is a longer answer but I haven't the time to type it, and I'm not sure that you would comprehend the answer..

__________________
There are two reasons for a man to do a thing, One that sounds good, and the real one...
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#12
In reply to #11

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 9:13 PM

Why do you not just answer my question , have a discussion about the facts or just stop replying to replies that are not intended for you ?

It might save you some stress.

There is a number at the corner of the reply box to convey this information.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 7)
Guru

Join Date: Oct 2008
Location: Deepest Darkest Rutherford Oz
Posts: 951
Good Answers: 145
#15
In reply to #12

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 9:44 PM

I did answer your question in response #10.

Which after posting I decided there required a more considered response.

But like teaching pigs to sing and post turtles I will concede to the diminising returns for effort.

__________________
There are two reasons for a man to do a thing, One that sounds good, and the real one...
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#17
In reply to #15

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 10:03 PM

I see no answers to the question which is :

Will this Circuit Allow Correct Battery Charging?

All I see is insults and rubbish replies.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 7)
Guru
United States - Member - New Member

Join Date: Mar 2010
Location: In the pool because it is too hot.
Posts: 3055
Good Answers: 140
#13

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 9:21 PM

Another new (electronic?) component: an Ampere meter (gauge).

Did you notice that this circuit allows the A meter to move in the same direction while charging the batteries as well when unloading the batteries.

The diagram is not complete, that is why I can't say more if the circuit is bad.

What I see is a nice way to use a regular A meter instead of one with a center zero and a needle that moves in 2 directions.

__________________
Plenty of room here
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#14
In reply to #13

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 9:29 PM

An Ampere meter is a winding (magnet.) arrangement not another new component.

Rectifiers tend to pass current in one direction.

Did you notice that the circuit would work perfectly well by including 2 more diodes ?

{The diagram is not complete, that is why I can't say more if the circuit is bad.}

The circuit was the one supplied it is complete as supplied !

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
Anonymous Poster
#16

Re: Will this Circuit Allow Correct Battery Charging?

08/01/2010 9:55 PM

whattya say we keep all the unsults, personal vendettas, and bad vibes out of the forum?

if I wanted things like that, I could go to an adult chat room

I come in here to learn, and I already know how to get mad and swear at other people

Register to Reply Off Topic (Score 5)
7
Power-User
Fans of Old Computers - ZX-81 - New Member

Join Date: Feb 2008
Location: Beirut Lebanon
Posts: 197
Good Answers: 8
#19

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 1:07 AM

Philip,

Why did you move the discussion to a new thread? It is a silly subject and is not worthy...

The Schematic you posted here was submitted by John in reply to a guest asking about reading the battery current with the same meter while batteries are charging or discharging.

This diagram got lot of discussions in the previous thread, I contributed in these discussions, I explained my technical point of views, I was not for this solution, John and others defend it, no body took it as personal.

You can explain your technical point of view also.

In summary, this circuit proposed by John is a simple and easy way to respond to the OP request... it will work, but has some incovenients, I stated the heat dissipation, and cost, voltage drop is another handicap, others are trying to deny it by complex equations have nothing to do with the real question...

Yes this circuit will generate voltage drop, and this voltage drop will disturb the operation of UPS, in both way charging and discharging,

What ever the method of charging is ( current controlled or voltage ) in current mode, the end of charge state will be read wrongly by the charging circuit and the battery will be over charged and this may destroy the battery if the "end of charge level" is not readjusted,

in constant voltage mode ( floating) the voltage applied to battery is always less by 0.92 volt and never become fully charged unless floating level is not readjusted .

here a disagree completly with Redfred

in inverter mode, the end of discharge state also will be read wrongly, it will read less by 0.92 volts ( in the case of schotky diodes) and the UPS will stop while the batteries are still charged,I never seen a battery could be discharged at 75% of its voltage ( 8 volts out of 12) how many cycles it may last?

I agree with you some 'Guru" have a high level of arrogance and turn it to personal level and insults when they feel "screwed" or their "superiority" is compromised, but you are obliged to enter this vicious circle

Tornado, GA number is not significant to qualify the credibility of a poster, GA's are not given by a non-biased jury, just by readers.

to all,

Please let us keep this forum for technical discussion, and if some comments you judge not worthy just ignor it

__________________
dont say it, write it
Register to Reply Good Answer (Score 7)
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 20969
Good Answers: 780
#21
In reply to #19

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 2:01 AM

I am well aware that GAs are as much a popularity contest as anything else. The point I was responding to was portugalphilip's suggestion that JohnDG might never have voted him any GAs. So I took a look. Apparently portugalphilip was correct, not only about JohnDG, but also any other possible pair of votes. C'est la vie.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Register to Reply
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8778
Good Answers: 376
#20

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 1:31 AM

Taken out of context, yes this circuit is NOT ideal. However this circuit (and additional information you have not included) relates (as you know) to the following thread in answer to the question (simplified) "how do I connect an ammeter in series with a UPS battery so that it doesn't go backwards when the UPS charges the battery?"

http://cr4.globalspec.com/thread/56177

The answer (in the form of the picture), AND the additional information in posts further explaining "how to connect the original poster's existing ammeter to get it to work" circuit in the above link (again which you have not included) clearly indicate the advantages and disadvantages of the circuit. As for your comment that is a bad circuit, it is actually an acceptable circuit (again when taken in context). It may not be as fancy as a hall effect transducer (and associated electronics) but it is very simple and very cheap and will work for many applications (including the original poster's existing ammeter). The most accurate, expensive and complicated solution is sometimes (more often than not) the best (and you can take that from an actual Engineer!).

Personally I would have just placed a set of change over contacts to mechanically swap the ammeter polarity (hence avoiding some of the disadvantages created by the diodes, but creating additional disadvantages). Which is better, again it depends on the specific application as neither are ideal for all situations (the "perfect" circuit).

Do you just have a problem with the two diode voltage drops potentially interfering with the charging? Perhaps you should do what the rest of us do and reply to the specific question thread and post response (which you have already done) rather than starting a new thread, that or at least provide more information.

__________________
jack of all trades
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#22
In reply to #20

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 4:58 AM

Surely there are diodes around with a very low voltage drop that would have little noticeable effect on the voltages.....years ago Germanium was the only answer, but today there are some better answers I feel....Schottky diodes?

See here:-

http://www.st.com/stonline/products/literature/ds/5511/stps120l15.pdf

Not completely charging a LA Battery will actually prolong its life and improve the efficiency......only charging to about 70% of the capacity is the "sweet spot" there!! You just need to increase the battery "size" by at least 30% to cover it....

I agree with you about a changeover relay, you win some and lose some.....swings and roundabouts!!

I personally would still go for the low drop Schottky diodes....they are available in quite large amp sizes....

Have a great day.

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#23
In reply to #22

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 11:47 AM

There is some diodes with very low forward volt drops.

If this type of circuit were to used I think maybe you could arrange the rectifier part from a FET (with associated circuitry.) and there is some FET's that have an on resistance of well less than 1 ohm.

From the original post of the advice given The Relay arrangement would be the best answer to the how do I connect a meter ? part but the question also asked what components would I connect ? so I gave my opinion that a hall effect device would be my choice.

Also I was surprised that someone would suggest such a poor circuit for a battery charging system. I mean are we not supposed to be engineers and realize the circuitry we employ.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#24
In reply to #23

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 2:01 PM

It may not be as poor as you think, LA batteries are voltage driven charging, so as long as you don't "Overcharge", the charger remains fairly simple.

If the applied voltage was say 13.2 volts to a nominal 12 volt LA battery, no overcharging would take place......nor would the battery be completely full either, as I said before, only about 70% full.

But it would not gas (lose water), it would not heat up and would have a remarkably long life....as long as its not "over discharged" either, or its a leisure type where it does not matter if its deep discharged.....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#25
In reply to #24

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 2:26 PM

{ It may not be as poor as you think }

I think it is really poor.

Yes overcharging a battery is really bad.

Yes batteries can even explode if gassing takes place.

Yes there are some batteries that don't care if they are deeply discharged.

But for me a battery charger is to charge batteries and not run circuitry between it and batteries.

I have no problem with this circuit if a second rectifier is fitted (or 2 shortable diodes.)

are fitted to the circuit to raise the battery reference by the same amount as the ammeter rectifier.

I do know why it was not included in the circuit in the first place and then I would have given it a good vote instead of question it.

Regards.

Philip.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#26
In reply to #25

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 3:02 PM

As we have not been informed about the value of the UPS voltage, that is only speculation.....

As I said before, if the voltage is correctly set up, no other circuitry or components are needed to charge correctly and not overcharge.......its why I use LA in my caravan and no other....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#27
In reply to #25

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 5:07 PM

Please help me out here - you seem to have come across a new electronic component. What is a Shortable Diode?

Regards.

John.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#28
In reply to #27

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 5:29 PM

A diode with a relay across it !

A diode is a P-N Junction and a relay is a device for connecting and disconnecting conductors.

If you power the coil of the relay with a voltage current source you can make the relay "short" out (bypass.) the diode and when the coil voltage current is removed make operative (allow to be functional as a diode.) or the other way around as relays have NO and NC contacts which means they are Normally "Open" or Normally "Closed" which means that they are either conductors or non conductors when the coil is under normal conditions which is generally understood as No coil voltage to the relay.

Diodes have generally 2 pin outs and Relays generally have more than 2 pin outs.

Pin outs means the amount of electrical connections you can make with the device.

So a Shortable Diode is a diode that you can make like a piece of wire or use as a diode.

Cumprementos....Regards.

Philip.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Score 1 for Off Topic
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#29
In reply to #28

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 5:34 PM

There - I gave you a GA. Best laugh I've had for a while. Thanks.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply Score 1 for Off Topic
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#30
In reply to #29

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 6:00 PM

I have a circuit for a shortable condenser and shortable resistor also but don't tell everyone as I have not got the patent in yet !

Thanks for the vote I may reciprocate sometime.

Regards.

Philip.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 5)
Anonymous Poster
#33
In reply to #22

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 10:10 PM

Andy Germany

Who told that charging a battery to only 70% of its full capacity will increase its life time ?

Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#53
In reply to #33

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:15 PM

If you read some in depth manuals on LA Batteries, you will find references to not gassing = longer life....any voltage over 13.2 volts (for a nominally 12 volt battery), WILL cause gassing.

Also (depending upon the type of L.A.B.) going below 12.6 volts for extended periods promotes sulfation, another killer of car type LABs...

Keeping a battery between those two values promotes longer life, which is why some cars have short lived batteries and others longer lives.....

I am actually testing this fact with a 120 A/H battery that I bought in 1999 for my caravan, its still going strong!!! And has only once had distilled water added.....about 3 years ago!!

I'll let you know when it "pops its clogs".....if I knew who the hell you were Mr (Mrs?) Troll.....

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Anonymous Poster
#61
In reply to #53

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 6:30 PM

Well ,don't go above 13.2V and you still able to charge the battery fully.

But to charge the battery to only 70% of its full capacity promotes partial sulfation for the 30% of its capacity which left with no charge.

Register to Reply
2
Power-User

Join Date: May 2010
Location: Cambridge, MA
Posts: 390
Good Answers: 82
#38
In reply to #22

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 3:54 AM

stps120l15 - That's a nice diode, only 0.25V drop at 10A. I love ST's ISOTOP package, but anything that comes in that package is rather expensive, $35 for this one at Newark.

I can't be supportive of the circuit, although I agree it won't damage the battery per se, merely under-charging it and under-discharging it, badly affecting the UPS capability (if the UPS circuit has a sense line that can be moved, that would fix the charging deficiency). And anyway, what's wrong with a say 50mV shunt and digital panel meter that indicates charge and discharge with a plus/minus sign? But hey, should an O.P. really want this functionality, I'd say that after adding a shunt or Hall-effect DC current sensor, they should use an electronic absolute-value circuit.

Alternately, if they really want to put their cash and energy into a rectifier bridge, they can consider using four power MOSFETs in place of the diodes, in an active-rectifier ideal-diode or synchronous rectifier bridge circuit. The FET is wired drain, source, so its body diode acts in place of the Schottky diode, and a comparator is used to turn on each FET's gate whenever its diode has a forward drop. There are ICs, like the LTC4354, 55, 57 and 58, others in that series, that are meant for this task. Inexpensive low-voltage MOSFETs can be had with an Rds(on) of say 5 milliohms max, for a voltage drop low enough not to badly affect the UPS, and low enough to avoid the need for large heat sinks. That'll work, but you can see that with all the trouble, it makes more sense to obtain a bipolar signal and process that, than to process the high current path.

Now, speaking of power electronics, it would be nice to add a gas-gauge IC to keep track of the battery's total charge. My UPS must have something like that, because it displays the battery charge with five bars on the panel. But a gas-gauge or fuel-gauge (why do they have to use gasoline terminology in the names?) could be added to an older UPS that is missing this feature. The IC company Maxim makes several good parts to consider, like their DS2780.

__________________
Thanks, Win
Register to Reply Good Answer (Score 2)
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#39
In reply to #38

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:22 AM

The problem is that my circuit was sketched out in response to a specific question, and is presented here out of context.

I'd be the last person to argue that it is a particularly "good" solution, but it is, I believe, the simplest answer to the original question.

As has been said before many times (elsewhere) "If I was going there ... I wouldn't start from here".

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply
Guru

Join Date: Oct 2008
Location: Deepest Darkest Rutherford Oz
Posts: 951
Good Answers: 145
#31

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 7:06 PM

I'm done, and like Andy I'm out this singing lesson too

__________________
There are two reasons for a man to do a thing, One that sounds good, and the real one...
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#32
In reply to #31

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 7:10 PM

You must be off to post some turtles then.

Good luck.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 6)
Guru

Join Date: Dec 2005
Location: Etats Unis
Posts: 1871
Good Answers: 45
#34

Re: Will this Circuit Allow Correct Battery Charging?

08/02/2010 11:15 PM

Not unless you have one of those new-fangled AC batteries... Er, uh, NO. Although it will likely cause it to blow up, which could be fun. Please provide video!

__________________
The hardest thing to overcome, is not knowing that you don't know.
Register to Reply Score 1 for Off Topic
Guru

Join Date: Dec 2005
Location: Etats Unis
Posts: 1871
Good Answers: 45
#36
In reply to #34

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 1:47 AM

Yeah, I missed the + sign on the mysterious ups box. But not knowing any more than is presented, there is no way to answer if it will work or if it will smoke or do nothing or do something poorly.

__________________
The hardest thing to overcome, is not knowing that you don't know.
Register to Reply Score 1 for Off Topic
Anonymous Poster
#35

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 1:42 AM

This circuit will work. We need to consider the forward drop of two diodes. Hence the charging voltage to be adjusted accordingly. Also, when the UPS takes power from battery, we will loss power in two diodes. I dont think this is a good design. But it will work.

Register to Reply Score 1 for Good Answer
Guru
Safety - Hazmat - New Member Safety - ESD - New Member Engineering Fields - Transportation Engineering - New Member Popular Science - Evolution - New Member Technical Fields - Procurement - New Member Hobbies - Target Shooting - New Member Popular Science - Cosmology - New Member Engineering Fields - Architectural Engineering - New Member Technical Fields - Marketing/Advertising - New Member Engineering Fields - Food Process Engineering - New Member

Join Date: Dec 2005
Location: Mariposa Ca
Posts: 5804
Good Answers: 114
#37

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 2:07 AM

Still working on that reading thing I see...

how is it anyone could make a determination, of the quality of the circuit, [which could be adjusted to compensate for the drop, for all we know] when the charger itself is a black box, with no specifications whatsoever.

you have also managed to run off what little support you had on the other thread...

Good job on extending the life of a thread started by a guest, who probably didn't come back & read any of the 75+ replies to his query

Register to Reply Score 1 for Good Answer
Anonymous Poster
#40

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 6:02 AM

The ammeter will indicate the amount of charge or discharge but not indicate which. You really need an ammeter that reads both + and - and get rid of the full wave bridge.

Register to Reply
Commentator

Join Date: Mar 2009
Location: Georgia mountains
Posts: 64
#41

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 10:53 AM

Hi portugalphilip,

The UPS typically will have a modified sine wave output containing significant harmonic content. The ammeter will display something but not RMS. Alternating current is routed to the battery causing heating, but no charging.

Regards,

Luther M

__________________
There are old pilots and there are bold pilots, but there are no old bold pilots.
Register to Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#43
In reply to #41

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 11:03 AM

Keep up, Luther !

The ammeter & diodes are between the UPS electronics and the UPS battery. There is NO AC PRESENT in the circuit shown! You may be getting confused by the AC symbols on the bridge.

(This is what happens when someone takes a post (in this case, a posted circuit) from another thread and starts discussing it out of context ).

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#52
In reply to #43

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:14 PM

You only say it is a UPS Battery charger it may provide a pulsed DC charging current which might be what the guest is talking about but yes...an AC Battery...that would definitely be a "New Component"......I must get down the patent office soon. !!

You may get a good answer soon :)

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Score 2 for Off Topic
Power-User

Join Date: Dec 2007
Posts: 177
Good Answers: 6
#42

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 10:55 AM

short answer: YES as long as polarity of source is maintained as shown.

Register to Reply
Anonymous Poster
#44

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 11:32 AM

Maybe I'm missing something here, but the circuit will not work because the ammeter is connected as a load and the battery is not. The battery will see an alternating current. The battery should be wired to the output of the bridge at the nodes of the ammeter. The ammeter should then be in series with one of the battery leads. No?

Register to Reply
Anonymous Poster
#45
In reply to #44

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 11:33 AM

P.S. - Most UPS that I'm familiar with are AC.

Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#55
In reply to #45

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:24 PM

It depends at which point in the circuit you are working with......all UPS batteries are DC (we have yet to invent an AC battery....) Understood????

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#60
In reply to #55

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:43 PM

Please be quiet...I am working on the AC battery at the moment....It would be a "New Component" for my posting....just got to get some magnetic lead and a revolveromonotruncatoring.....I Think the poster is confused as they plug their UPS into an AC socket and they think that a Battery is charged by AC.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply Off Topic (Score 8)
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#54
In reply to #44

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:23 PM

Abuse/Attack:

This post was deleted because it was an attack on another user. Please review the CR4 Site FAQ.

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
4
Guru

Join Date: Jun 2006
Location: Ottawa Canada
Posts: 1975
Good Answers: 117
#46

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 12:36 PM

This is a funny circuit. The addition of a bridge rectifier in a DC system is a bit funny, until I went back to the original thread and saw that the UPS sometimes exceeded the battery voltage and sometimes the battery drove the UPS. So sometimes the positive terminal of the battery was negative with respect to the output from the UPS. Tricky!! And clever!

It looks out of place since there is no traditional AC involved. The idea of the bridge rectifier was to make sure that power goes through the ammeter in the same direction no matter which direction the current is flowing. An assumption is that the "A" is an ammeter shunt. Another assumption is that the UPS is correctly charging the battery now. Another assumption would be that anything which would cause voltage drops will degrade its charging performance.

So the correct answer to the OP's question on this thread would be "unless you change the output by increasing the voltage of the UPS, this circuit will add too many voltage drops to allow the battery to efficiently charge.

As has been said many times in these two threads, a better solution is to get a centre reading ammeter. Even the gentleman who came up with the circuit mentioned that he would not use it himself, that the circuit was just to show that it would be possible. Not that it would be efficient or even useful, though of course it is. But I am glad to have seen a use for such a clever circuit!

__________________
If it was easy anybody could do it.
Register to Reply Good Answer (Score 4)
Anonymous Poster
#47
In reply to #46

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 2:04 PM

Nothing clever in this circuit,two diodes of the four diodes of this bridge rectifier have no use, wasting money. This circuit is just equivalent to single diode connected in series with a meter.

What is clever you talking about ?

Register to Reply Score 2 for Off Topic
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#57
In reply to #47

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:29 PM

DUUUUHHHHH!

Think about charge and discharge.

Think about CURRENT direction.

Then you will see that the meter (not being a center zero, or digital) can show both charge and discharge on the meter needle, without wrecking it!!!

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#56
In reply to #46

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:27 PM

GA from me.

Yusef1, we don't always see "eye 2 eye", but I must compliment you on your post, simple but stunningly correct!!!

Many thanks.

I am sure that John DG will also be a (little) bit grateful too!!

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#63
In reply to #46

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 6:54 PM

A bit of sanity at last. Thankyouthankyouthankyou.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply Off Topic (Score 5)
Power-User

Join Date: Jul 2007
Location: Orlando
Posts: 242
Good Answers: 3
#48

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 2:13 PM

The circuit will work.

The bridge rectifier only provides steering charge and discharge current. Schotky diodes may not be necessary as the DC/AC UPS inverter may operate with 11VDC.

The UPS does not source AC.

The ammeter will indicate both charge and discharge currents. No need for center scale zero and such indication. Every UPS I've ever seen has LED indicators for like "Standby" or "On/On-Line" mode.

Are we clear yet?

You guys have beat this one to death. More like to a pulp.

Remains a mystery as to why inductance and "Q" was brought in. Think by the OP.

Register to Reply
Anonymous Poster
#49
In reply to #48

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 2:26 PM

The battery will supply DC current into the UPS , and the battery will be charged by a battery charger.

Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#51
In reply to #48

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:10 PM

No it will not it is a battery charger with the charger looking at a volt drop between it and its intended target.

Please read the title of the question and then any replies.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
Guru

Join Date: Dec 2005
Posts: 1601
Good Answers: 19
#59
In reply to #48

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:39 PM

Is there any way I could tap the heat out of this discussion to run a Rankine cycle? Might be able to generate some electricity for this wheatstone bridge circuit battery charger.

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#65
In reply to #59

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 7:00 PM

You could run a city from my personal boiler !

__________________
"Love justice, you who rule the world" - Dante Alighieri
Register to Reply Off Topic (Score 5)
Anonymous Poster
#50

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 3:08 PM

Just remove the bridge rectifier form the circuit and keep the meter , will be the same.

Register to Reply Score 1 for Off Topic
Guru
Popular Science - Weaponology - New Member Safety - ESD - New Member Hobbies - Fishing - New Member

Join Date: Sep 2006
Location: Near Frankfurt am Main, Germany. 50.390866N, 8.884827E
Posts: 17996
Good Answers: 200
#58
In reply to #50

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 4:31 PM

Not if its an older "needle" type meter with zero on the LH side.......think!!!

If you had a clue what you are talking about you would have posted with your "real" CR4 name, instead of jest guest!

__________________
"What others say about you reveals more about them, than it does you." Anon.
Register to Reply
Anonymous Poster
#62
In reply to #58

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 6:51 PM

I am talking about a meter with needle in the middle so you will be able to know if the current charging or discharging.

Register to Reply
Commentator

Join Date: Mar 2007
Location: Tex us
Posts: 57
Good Answers: 1
#64

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 7:00 PM

WOW! What a post! I'll be sure to mind my p's and q's next time I have a query.

My simple answer is NO. It will NOT permit the UPS to "see" the battery voltage correctly.

My reasoning is that the breakover voltage of the diodes will introduce a 1.4 volts overcharge (if it's a standard silicone rectifier) AND an under-discharge cutoff with the same error.

The ammeter WILL function but only if charging or discharging and the readings will be the same polarity whether discharging or charging.

If I wanted to monitor the current to or from the battery, I would use a center zero 12 vdc ammeter (suggested in previous post). Though the coil resistance of the mechanical ammeter WILL introduce a slight voltage drop, I don't believe it would be significant enough to interfere with the ups voltage sense circuitry.

I purchased a DC clamp on ammeter that'd work great but at 300 bucks, well...

__________________
me thinks, therefore I am - I think?
Register to Reply
Power-User

Join Date: May 2010
Location: longo tempo dos macaco do pilas. Felizment.
Posts: 251
#66
In reply to #64

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 8:44 PM

Yes you are correct.

In reply to : My simple answer is NO. It will NOT permit the UPS to "see" the battery voltage correctly.....That is the whole point of my post.......The circuit is junk...why destroy you batteries just to see a reading on a cruddy ammeter...do it correctly and do as you do and buy a hall effect meter and bingo you have your readings and a useful tool also instead of an inaccurate meter / bad batteries and a possible loss of the functionality of your system.

__________________
I am a deeply religious nonbeliever - this is a somewhat new kind of religion. Albert Einstein
Register to Reply
2
Power-User
Fans of Old Computers - ZX-81 - New Member

Join Date: Feb 2008
Location: Beirut Lebanon
Posts: 197
Good Answers: 8
#67
In reply to #66

Re: Will this Circuit Allow Correct Battery Charging?

08/03/2010 11:31 PM

This become a silly discussion,

Philip, If you have more serious thread please post, else please close this thread,

Administrator, please close this thread, it is time wasting for the forum resources

__________________
dont say it, write it
Register to Reply Good Answer (Score 2)
Register to Reply 67 comments
This discussion was "closed" on 08/03/2010 11:48 PM. No new comments are allowed.
Message from admins:
This circuit was taken out of context from another post and is an abuse/attack on another CR4 user. Please review the CR4 Site FAQ and keep things friendly.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Andy Germany (9); Anonymous Poster (11); Bill ML (1); dvmdsc (1); Garthh (1); jack of all trades (1); JohnDG (7); Le_Noble (2); leskranes (1); lrsheldon (1); Luther M (1); portugalphilip (16); rcapper (2); redfred (3); Ried (1); Tobugrynbak (4); Tornado (3); Winfield Hill (1); Yusef1 (1)

Previous in Forum: Percentage of Error in Analog Meter Readings   Next in Forum: Can I Run an Alternator with Electrical Motor?
You might be interested in: Industrial Batteries, Reserve Batteries

Advertisement