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building usb-remote-cable

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Offline Shadow_weaver462

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Re: building usb-remote-cable
« Reply #400 on: 08 / January / 2012, 19:51:24 »
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Two more shots of the inner workings. I was too lazy to remove and re-solder the remote's original power-switch to always on.
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Offline Pier

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Re: building usb-remote-cable
« Reply #401 on: 09 / January / 2012, 06:26:01 »
NightPhotoNoob

Cellphone batteries have 3 terminals:
(+) (-) and 3th terminal is used from Cellphone to control when to interrupt charging.
Interrupting occurs when battery reach 4.2 or 4.3 V.
The simple chargers are designed to charge with current between 250 and 450 Ma.Output voltage 5 to 6 volts.But the charger is designed also  to limit the charging current in above limit.
Inside in most batteries is placed simple electonic circuit wich interact with the phone by 3th terminal to stop charging when upper limit of voltage is reached (max 4.3v)... in most cases 4.2 V.
Li-Ion batteries charged to 4.2 v are not full charged - only 70%.But this is very safe and keep from accidents with battery.
When 4.3v is reached charging must continue for full charge by special manner-NOT in CELLPHONES, but in special chargers.
This 4.3v is max voltage for Li-Ion and safe they longlife.Above this is also dangerous...
====================================================
You  must charge with current not above 450 Ma -500 Ma (can be less) watchig with voltmeter in the hands when voltage will gain 4.2-4.3 v and immediate interrupt the charging.Overcharge is dangerous, and if not happened explosion e.t.c. this shorten battery life.
If the current is many above 450 Ma simply use R (Resistor) several Ohms (depend of chargers output voltage) in series with any of wires to limit the current.Less current - long time to charge to 4.2V...and more safe !
Have success !
« Last Edit: 09 / January / 2012, 06:39:03 by Pier »
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Offline NightPhotoNoob

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Re: building usb-remote-cable
« Reply #402 on: 09 / January / 2012, 07:54:13 »
@Pier,
Thanks for the info, I will be sure to use all three of the terminals in my charging unit. 


@Shadow_weaver462,
Very, very nice remote.  Amazing.  I couldn't even dream of making such a professional device.  Well done, and keep up the good work!
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Canon PowerShot SX150 IS
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Offline fvdk

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Re: building usb-remote-cable
« Reply #403 on: 11 / January / 2012, 06:32:28 »
Quote from: Pier on 09 / January / 2012, 06:26:01
NightPhotoNoob

Cellphone batteries have 3 terminals:
(+) (-) and 3th terminal is used from Cellphone to control when to interrupt charging.
Interrupting occurs when battery reach 4.2 or 4.3 V.
The simple chargers are designed to charge with current between 250 and 450 Ma.Output voltage 5 to 6 volts.But the charger is designed also  to limit the charging current in above limit.
Inside in most batteries is placed simple electonic circuit wich interact with the phone by 3th terminal to stop charging when upper limit of voltage is reached (max 4.3v)... in most cases 4.2 V.
Li-Ion batteries charged to 4.2 v are not full charged - only 70%.But this is very safe and keep from accidents with battery.
When 4.3v is reached charging must continue for full charge by special manner-NOT in CELLPHONES, but in special chargers.
This 4.3v is max voltage for Li-Ion and safe they longlife.Above this is also dangerous...
====================================================
You  must charge with current not above 450 Ma -500 Ma (can be less) watchig with voltmeter in the hands when voltage will gain 4.2-4.3 v and immediate interrupt the charging.Overcharge is dangerous, and if not happened explosion e.t.c. this shorten battery life.
If the current is many above 450 Ma simply use R (Resistor) several Ohms (depend of chargers output voltage) in series with any of wires to limit the current.Less current - long time to charge to 4.2V...and more safe !
Have success !

Apparently, you have no idea what you are talking about and your information is false.

The 3rd contact on cellphone batteries is for temperature monitoring and is not used to determine if the battery is fully charged.

Li-ion cells are fully charged at 4.2V but most chargers will slightly undercharge to 4.1 - 4.19V
A proper CC/CV charger will stop charging when the battery reaches the voltage threshold and the current drops to three percent of the rated current. A battery is also considered fully charged if the current levels off and cannot go down further.

Please read the very good information on Battery University

http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

or the Panasonic documentation:

http://industrial.panasonic.com/www-data/pdf/ACI4000/ACI4000PE5.pdf

« Last Edit: 11 / January / 2012, 06:35:26 by fvdk »
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Offline Pier

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Re: building usb-remote-cable
« Reply #404 on: 11 / January / 2012, 07:37:12 »
@fvdk,
Quote
Li-ion cells are fully charged at 4.2V but most chargers will slightly undercharge to 4.1 - 4.19V
No, I'm not agree that not only from my experience long years.Anothers sources (many sources) said 4.3 v

I"ve croped this from Power stream site long time ago (have not link...sory):
Quote
  POWER STREAM PAGE   
Lithium-ion Battery Charging Basics 
 
Lithium Ion Charging

Basics

These remarks apply equally to lithium ion and lithium polymer batteries. The chemistry is basically the same for the two types of batteries, so charging methods for lithium polymer batteries can be used for lithium-ion batteries.
Charging lithuim iron phosphate 3.2 volt cells is identical, but the constant voltage phase is limited to 3.65 volts.
The lithium ion battery is easy to charge. Charging safely is a more difficult. The basic algorithm is to charge at constant current (0.2 C to 0.7 C depending on manufacturer) until the battery reaches 4.2 Vpc (volts per cell), and hold the voltage at 4.2 volts until the charge current has dropped to 10% of the initial charge rate. The termination condition is the drop in charge current to 10%. The top charging voltage and the termination current varies slightly with the manufacturer.
However, a charge timer should be included for safety.

The charge cannot be terminated on a voltage. The capacity reached at 4.2 Volts per cell is only 40 to 70% of full capacity unless charged very slowly. For this reason you need to continue to charge until the current drops, and to terminate on the low current.

It is important to note that trickle charging is not acceptable for lithium batteries. The Li-ion chemistry cannot accept an overcharge without causing damage to the cell, possibly plating out lithium metal and becoming hazardous.

The question occasionally comes up "What is the effect of charging with less than 4.2 volts?" Unlike other battery chemistries the battery will charge, but it will never reach full charge, it will only be partly charged. The reason for this is that stuffing the ions into the anode or cathode crystals requires more voltage than the simple electrochemical cell voltage. The higher the voltage the more ions can be inserted. The page linked page here some quantitative data on the relative capacity of lithium-ion batteries that are charged below 4.2 volts.

Charging Lithium ion batteries at slow rates

When the charge rate during the constant current phase is low, the charger process will spend less time during the constant voltage tail. If you charge below about 0.18 C, the cell is virtually full when the 4.2 volts is reached. This can be used as an alternative charge algorithm. Just charge below 0.18C constant current and terminate the charge when the voltage reaches 4.2 volts per cell.

Safety

Every lithium ion battery pack should have (must have?) a safety board which monitors the charge and discharge of the pack, and prevents dangerous things from happening. The specifications of these safety boards are dictated by the cell manufacture, and may include the following:

Reverse polarity protection
Charge temperature--must not be charged when temperature is lower than 0° C or above 45° C.
Charge current must not be too high, typically below 0.7 C.
Discharge current protection to prevent damage due to short circuits.
Charge voltage--a permanent fuse opens if too much voltage is applied to the battery terminals
Overcharge protection--stops charge when voltage per cell rises above 4.30 volts.
Overdischarge protection--stops discharge when battery voltage falls below 2.3 volts per cell (varies with manufacturer).
A fuse opens if the battery is ever exposed to temperatures above 100° C.


 Look at this too.

http://www.fairchildsemi.com/an/AN/AN-9721.pdf
I know that when charge process end there is smal drop in charge curent and "smart" chargers edns charging.But the word was for simple , safe , in home charging.Who say the Truth ??
8 Years I charge in my Home 7 Li-Ion cells for several equipments to 4.3v with simple charger and they working exelent till now.BUT - I watch careffuly charge process and end it on 4.29 - 4.3 v
For 3th terminal Im not 100% sure, will check for sure to know truth.
Thanks.

Edit1 - In the my link above is clearly mentioned that inside every battery have protected circuit agaist overcharging and discharging ! I"m right... right ?... (smail...)
« Last Edit: 11 / January / 2012, 07:54:26 by Pier »
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Offline fvdk

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Re: building usb-remote-cable
« Reply #405 on: 11 / January / 2012, 08:02:38 »
Quote from: Pier on 11 / January / 2012, 07:37:12
@fvdk,
Quote
Li-ion cells are fully charged at 4.2V but most chargers will slightly undercharge to 4.1 - 4.19V
No, I'm not agree that not only from my experience long years.Anothers sources (many sources) said 4.3 v

I"ve croped this from Power stream site long time ago (have not link...sory):


If you read your own quoted message from the Power stream site, than you will see that it says exactly what I have told, you are misreading what is says.

When charging, the charger will first use a CC (constant current) stage until the charge voltage reaches 4.2V (at that time the cell is indeed charged to about 70% of it's capacity) however, it will than keep the voltage at 4.2V (+/- 0.05V) and switch to the CV (constant voltage) stage where the current will slowly drop until it reaches 3% of the cell capacity or until the current levels off and cannot go down further. This is the stage in which the cell will reach it's full charge.

With a proper designed charger, if you than take the cell of the charger and measure the voltage, you will see that it is at 4.2V or like I said, slightly lower if it is an older cell or a less well designed or conservative charger.

According to the specifications of all Li-ion manufacturers, the charge voltage should never exceed 4.2V (+/- 0.05V).

In battery packs (multiple cells) or cylindrical cells, a protection circuit is build-in or added which will kick-in if the voltage goes above 4.3V but mind you, this is an added protection to prevent explosion just in case the charges does go above 4.3V which a proper charger would never do.

If your charger constantly charges your cells to 4.3V than it does not follow a proper CC/CV algorithm and it probably does not cut-off like it is supposed to do. At best, it shortens the lifespan of your cells and in the worst case, it could overcharge your cells and cause them to explode.
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Offline fvdk

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Re: building usb-remote-cable
« Reply #406 on: 11 / January / 2012, 08:21:46 »
Quote from: Pier on 11 / January / 2012, 07:37:12
Edit1 - In the my link above is clearly mentioned that inside every battery have protected circuit agaist overcharging and discharging ! I"m right... right ?... (smail...)

You should understand the difference between a battery (multiple cells combined in a package) and single cells.

For battery packs, a low discharge / over charge protection circuit is mandatory.

Single cells only have a safety membrane (temperature fuse). If the control switches experience abnormal heating, this fuse cuts off the current (non-restoring). This is why for safe use for example in flashlights, a separate protection circuit is added to the cell.
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Offline Pier

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Re: building usb-remote-cable
« Reply #407 on: 11 / January / 2012, 11:47:36 »
@fvdk
Quote
You should understand the difference between a battery (multiple cells combined in a package) and single cells

Yes, I do.
And I do not know 4.3 v Li-Ion Battery  ;).All in the text about figures 4.3, is not for battery but for cells.

Thanks and good Luck.
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Offline ryandigweed

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Re: building usb-remote-cable
« Reply #408 on: 01 / February / 2012, 10:17:19 »
Can someone help me out please?. I've built one of these. But the current is flwing constantly, and stops when i press the button, (actually the opposite of what it's supposed to do) I checked it by placing an LED at the positive and negative points on the USB socket

The Switch im using

« Last Edit: 01 / February / 2012, 10:29:21 by ryandigweed »
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Offline Pauls9

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Re: building usb-remote-cable
« Reply #409 on: 01 / February / 2012, 10:24:13 »
Sounds like you've got a normally-closed switch. You need a normally-open one.
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