How to calculate the performance of a battery charger (LR06)

[thiethie13]

Hello,
I would like to know how to calculate the efficiency of a battery charger for LR06 for example.
I will measure EDF electrical consumption with an energy meter during a charge cycle and I will also obtain the capacity of the battery through a test bench by discharging it at 0,2 it ( 500mA for example for a 2500mAh) but up to 0,8V only and not 0 !!

Do you have any advice to give me based on the data I have collected?
Thank you

[Christophe]

Houlà if you want an acceptable precision, you will need a great precision on the EdF measurement side!

Ditto for the discharge (but there you seem to the point) because it is not because a battery is given for 800 mAh which actually has 800 mAh.

Otherwise I'm curious to see the results, I predict a charge efficiency of 20 to 30%, no more.

So my advice is rather a question: how will you estimate EDF consumption?

My most accurate outlet meter gives 1 to 3W when recharging 4 LR06 ... it is not very sufficient accuracy for my taste.

I found an old subject on the consumption of a battery charger that should interest you: https://www.econologie.com/forums/consommati ... t3517.html and a much more recent one that should more than interest you: https://www.econologie.com/forums/duree-de-v ... 10160.html (with lots of discharge curves)

[thiethie13]

Thank you for your elements
Indeed, I have precise equipment for measuring energy consumption, but I am blocking the formula to obtain a return.
In my opinion it is the energy contained in the battery divided by consumed EDF energy.
On the other hand in terms of unity, I have for the first mAh and for the second Joules ...
How do I recover equivalent units ... ??

Thank you

[I Citro]

It's a good question.
As the LR06 (and LR03) batteries are intended for basic general public use, the manufacturers do not care and happily surf the wave of "we guzzle ourselves by selling anything" ...

There are "decent batteries" on the market, but when it comes to chargers, it's nonsense.
- Most chargers have a very approximate "floating" function as evidenced by the temperature of the batteries ...
- Most chargers do not manage the individual charge but the charge of 2 batteries together (in series).
Finally when we look at charge management electronics, the majority of products are ultra basic ...

[I Citro]

Indeed, I have precise equipment for measuring energy consumption, but I am blocking the formula to obtain a return.
In my opinion it is the energy contained in the battery divided by consumed EDF energy.

Not quite because your calculation would include the efficiency of the charge (electrochemical losses with Joule effect) AND the efficiency of the charger (electrical, electromagnetic losses, Joule effect).

On the other hand in terms of unity, I have for the first mAh and for the second Joules ...
How do I recover equivalent units ... ??

Google is your friend, here for example:

* 1 Watt = 1 Joule for one second.

Energy (E in Joules) = W (Power in watt) xt (time in seconds)
* 1 Watt = 1 Joule for one second.
Energy (E in Joules) = W (Power in watt) xt (time in seconds)

So 1 Watt for 1 hour = 3600 Joules.

I stop there, because a load is a calculation of the derivative of the tension compared to the derivative of time with losses by Joule effect ...

[dedeleco]

On the other hand in terms of unity, I have for the first mAh and for the second Joules ...
How do I recover equivalent units ... ??

We sum, rather we integrate, over time all the products of the current in A by the voltage in volts by the time delta-t in seconds, during which this current remained almost constant to have Joules.
therefore mA = A / 1000
The mAh is the charge output from the battery with a current of 1mA = 1A / 1000 for one hour, i.e. in 3600s which gives 1 / 1000x3600 = 3,6Coulombs

For a constant 1,2V battery which outputs 500mA for 3 hours, we obtain an energy output from this battery:
1,2Vx500mA/1000x3h=1,2x0,5x3=1,8Wh=1,8x3600=6480Joules

read the basics:
http://fr.wikipedia.org/wiki/%C3%89nerg ... 9lectrique
http://fr.wikipedia.org/wiki/Int%C3%A9g ... atiques%29

example 500mA constant with:
1,4v over 0,5h, then 1,3V over 1h, then 1,2V 1h and 1,1V over 0,5h:
the energy is:

0,5 (1,4 x 0,5 + 1,3 x 1 + 1,2 x 1 + 1,1 x 0,5) = 1,875Wh = 6750Joules

The efficiency is indeed this energy measured out of the battery, divided by the energy expended by the charger, measured by the wattmeter during charging, if it is fairly precise (low energy of a few Wh).
We can check by measuring the alternating current on the 220V, integrated on the charging times and multiplied by the cos (phi) of the charger (phi = phase shift between current and voltage).

[thiethie13]

I have to reread calmly but actually I have the impression that you are falling back on your feet to find a real ratio, energy on energy.

Thank you very much for your research. I will come back to you if necessary and give you results to satisfy your curiosity!

[dedeleco]

It is not about:

you fall back on your feet

but not to mix or confuse frogs with oxen.

[hic]

Thank you for your elements
Indeed, I have precise equipment for measuring energy consumption, but I am blocking the formula to obtain a return.
In my opinion it is the energy contained in the battery divided by consumed EDF energy.
On the other hand in terms of unity, I have for the first mAh and for the second Joules ...
How do I recover equivalent units ... ??

Thank you

Hi thiethie13

Consumption is done in Wh
whether the battery or the charger

How do you measure to integrate variations?
here is the problem

[dedeleco]

How do you measure to integrate variations?

for once, with patience, it can be done with a stopwatch, a voltmeter and an ammeter and noting the values ​​at time intervals noted on a paper.

Otherwise it can be done with a microprocessor programmed for that which measures and calculates.
In addition there are integrated circuits realizing this entirely automatically and used in the commercial wattmeters.
see Maxim-ic.com
http://www.maxim-ic.com/datasheet/index.mvp/id/6454


microchip.com
http://www.microchip.com/
http://www.embeddedstar.com/weblog/2007 ... p-mcp3909/

and many others :
http://www.futurlec.com/News/Analog/Energy.html
http://www.google.fr/search?num=100&hl= ... =&aql=&oq=


http://www.microchip.com/stellent/idcpl ... odeId=2889
http://www.google.com/powermeter/about/index.html