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Topic: [Solved]Measure a battery amps (Read 8353 times) previous topic - next topic

jbarchuk


So by this, tell me what's the best way to charge a lipo battery.


The way the -battery- -manufacturer- says to, for the part number printed on the battery. Wikipedia lists 24 different 'lithium' chemistries. Lithium is the family name -lithium ion and lithium polymer are not necessarily synonyms. Voltages and charge/discharge characteristics vary *DRASTICALLY*.

Quote
I've followed this topic: http://forum.arduino.cc/index.php?topic=230870.0
Do you think i'm ok with that?


That looks like the straight dope.

CrossRoads

MAX1811 is easy to use for a LiPo.
Here I used one to charge a 1000mAH LiPo in my RF remote control.
I used 3AA battery pack for development, then connected the LiPo when I get the other parts in.
Has been running since ~Jan 2011.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

tsunamy_boy


Quote
I've followed this topic: http://forum.arduino.cc/index.php?topic=230870.0
Do you think i'm ok with that?

That looks like the straight dope.

Why  :smiley-roll-sweat:


MAX1811 is easy to use for a LiPo.
Here I used one to charge a 1000mAH LiPo in my RF remote control.
I used 3AA battery pack for development, then connected the LiPo when I get the other parts in.
Has been running since ~Jan 2011.


Do you have the need to setup resistors based on the amps that your batteries have?

CrossRoads

No. Lower left resistor is there to set Enable High or Low depending on whether external power is available. Upper right resistor is there to limit current to the charge indicator LED for brightness control.
Pins 1 & 2 determine whether it charges to 4.1V or 4.2V, and at 100mA rate or 500mA rate.

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

tsunamy_boy


Pins 1 & 2 determine whether it charges to 4.1V or 4.2V, and at 100mA rate or 500mA rate.

The IC does that automatically?


(...) at 100mA rate or 500mA rate.

This means that i can't charge a battery bellow 100mA or above 500mA?

retrolefty



Pins 1 & 2 determine whether it charges to 4.1V or 4.2V, and at 100mA rate or 500mA rate.

The IC does that automatically?


(...) at 100mA rate or 500mA rate.

This means that i can't charge a battery bellow 100mA or above 500mA?


Yes, and yes.

CrossRoads

Yes, the chip controls the level.
100 & 500mA are the rates supported by this chip. USB as the current source.
I suppose if the source can't supply that much, it will use whatever is available.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

tsunamy_boy


Yes, and yes.

Thank you :)


Yes, the chip controls the level.
100 & 500mA are the rates supported by this chip. USB as the current source.
I suppose if the source can't supply that much, it will use whatever is available.

Thank you, is there any other chip like that that can handle until 1Amp?

CrossRoads

Don't know. Search "battery management" at www.maxim-ic.com
or www.maximintegrated.com
My chrome is having a hard time connecting to maxim right now for some reason.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

This will do 1A, need to have the exposed pad connected for cooling.
http://www.digikey.com/product-detail/en/BQ24090DGQT/296-25863-1-ND/2237301
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

tsunamy_boy


This will do 1A, need to have the exposed pad connected for cooling.
http://www.digikey.com/product-detail/en/BQ24090DGQT/296-25863-1-ND/2237301

If i understood it charges batteries at 10mA min and 1000mA max right?

What does this means: "Pin Selectable USB 100mA and 500mA" cuz i'm confused about this

CrossRoads

Read the Pin Functions on page 7:

ISET2, pin 7:
Programming the Input/Output Current Limit for the USB or Adaptor source:
High = 500mAmax,
Low = ISET, (another pin, see below)
FLOAT = 100mA max.

ISET, pin 6:
Programs the Fast-charge current setting. External resistor from ISET to VSS defines fast charge current value. Range is 10.8k (50mA) to 540 ? (1000mA).

Also read more about these 2 pins on pages 18, 19.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

tsunamy_boy


Read the Pin Functions on page 7:

ISET2, pin 7:
Programming the Input/Output Current Limit for the USB or Adaptor source:
High = 500mAmax,
Low = ISET, (another pin, see below)
FLOAT = 100mA max.

ISET, pin 6:
Programs the Fast-charge current setting. External resistor from ISET to VSS defines fast charge current value. Range is 10.8k (50mA) to 540 ? (1000mA).

Also read more about these 2 pins on pages 18, 19.


And i have to calculate a resistor to different battery amps right?

retrolefty



Read the Pin Functions on page 7:

ISET2, pin 7:
Programming the Input/Output Current Limit for the USB or Adaptor source:
High = 500mAmax,
Low = ISET, (another pin, see below)
FLOAT = 100mA max.

ISET, pin 6:
Programs the Fast-charge current setting. External resistor from ISET to VSS defines fast charge current value. Range is 10.8k (50mA) to 540 ? (1000mA).

Also read more about these 2 pins on pages 18, 19.


And i have to calculate a resistor to different battery amps right?


Yes

tsunamy_boy

humm then i already have similar to that =)
I would go with a charger that doesn't need changes :P

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