Hello, a quick question, if I apply 4 volts to the DCIN input at 0.6A, what would be the time for charging a 1000mAh LiPo battery? Is there any equation? or calculation for me to use with other LiPo capacity?
Thank you,
Daniel P
USB LiIon/LiPoly charger, charging calculation
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- wildtang3nt
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Re: USB LiIon/LiPoly charger, charging calculation
The Adafruit chargers charge at a maximum rate of 500mA without modification, so a safe guess would be a couple hours.
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Re: USB LiIon/LiPoly charger, charging calculation
Hey! thank you for the reply,
I have made wrong my question, I have a little generator capable to provide 4 volts aprox and a current of 0.6 A aprox.
This is a Thermoelectric generator that will provide 4.3 V and 0.6 A working in the "best conditions".
How much current the charger will draw from my generator? for charging at 500mA (as factory default)
Or, using this setup, is there a way to calculate or estimate time for charging a 1 mAh LiPo battery?
Thank you again,
Daniel P
I have made wrong my question, I have a little generator capable to provide 4 volts aprox and a current of 0.6 A aprox.
This is a Thermoelectric generator that will provide 4.3 V and 0.6 A working in the "best conditions".
How much current the charger will draw from my generator? for charging at 500mA (as factory default)
Or, using this setup, is there a way to calculate or estimate time for charging a 1 mAh LiPo battery?
Thank you again,
Daniel P
- john444
- Posts: 443
- Joined: Sun Mar 04, 2012 2:42 pm
Re: USB LiIon/LiPoly charger, charging calculation
Hi Danidub,
your 4-V thermionic generator or about 17-mA.
The generator will not put any charge into the attached LiPo until the generator's output exceeds the LiPo voltage + 0.3-V. If the LiPo is low you may get some charge but it will taper off as the LiPo voltage increases. The result is: it will never reach full charge and even partial charging times will become excessive.
It is necessary to exceed the charging voltage as well as the operating voltage of the internal circuitry.
The internal circuitry needs about 0.3-V more than the charging voltage of 4.2-V (or 4.5-V).
When operating properly, the charging current varies during the charge cycle.
You might refer to the data-sheet and tutorials for the details.
http://www.microchip.com/wwwproducts/De ... e=en020210
http://learn.adafruit.com/usb-dc-and-so ... ly-charger
According to the datasheet, the USB LiPo charger (Id: 280) requires a minimum of 4.5-V for operation. I would speculate that only the idle current would be drawn fromdanidub wrote: if I apply 4 volts to the DCIN input at 0.6A, what would be the time for charging a 1000mAh LiPo battery?
your 4-V thermionic generator or about 17-mA.
The generator will not put any charge into the attached LiPo until the generator's output exceeds the LiPo voltage + 0.3-V. If the LiPo is low you may get some charge but it will taper off as the LiPo voltage increases. The result is: it will never reach full charge and even partial charging times will become excessive.
It is necessary to exceed the charging voltage as well as the operating voltage of the internal circuitry.
The internal circuitry needs about 0.3-V more than the charging voltage of 4.2-V (or 4.5-V).
When operating properly, the charging current varies during the charge cycle.
You might refer to the data-sheet and tutorials for the details.
http://www.microchip.com/wwwproducts/De ... e=en020210
http://learn.adafruit.com/usb-dc-and-so ... ly-charger
-
- Posts: 24
- Joined: Fri Apr 13, 2012 4:40 pm
Re: USB LiIon/LiPoly charger, charging calculation
Hello john444!
I have a little generator capable to provide 4 volts aprox and a current of 0.6 A aprox.
This is a Thermoelectric generator that will provide 4.3 V and 0.6 A working in the "best conditions".
How much current the charger (https://www.adafruit.com/products/259) will draw from my generator? for charging at 500mA (as factory default)
Or, using this setup, is there a way to calculate or estimate time for charging a 1 mAh LiPo battery?
Thank you again,
Daniel P
John, thank you for your answer, maybe it was my mistake, but I'm not using the charger id 280, I'm usning id 259 (https://www.adafruit.com/products/259) and in the datasheet is written Vmin 3.75 — Vmax 6. According to this data, it goes again my question:john444 wrote: According to the datasheet, the USB LiPo charger (Id: 280) requires a minimum of 4.5-V for operation. I would speculate that only the idle current would be drawn from your 4-V thermionic generator or about 17-mA.
The generator will not put any charge into the attached LiPo until the generator's output exceeds the LiPo voltage + 0.3-V. If the LiPo is low you may get some charge but it will taper off as the LiPo voltage increases. The result is: it will never reach full charge and even partial charging times will become excessive.
It is necessary to exceed the charging voltage as well as the operating voltage of the internal circuitry.
The internal circuitry needs about 0.3-V more than the charging voltage of 4.2-V (or 4.5-V).
When operating properly, the charging current varies during the charge cycle.
You might refer to the data-sheet and tutorials for the details.
http://www.microchip.com/wwwproducts/De ... e=en020210
http://learn.adafruit.com/usb-dc-and-so ... ly-charger
I have a little generator capable to provide 4 volts aprox and a current of 0.6 A aprox.
This is a Thermoelectric generator that will provide 4.3 V and 0.6 A working in the "best conditions".
How much current the charger (https://www.adafruit.com/products/259) will draw from my generator? for charging at 500mA (as factory default)
Or, using this setup, is there a way to calculate or estimate time for charging a 1 mAh LiPo battery?
Thank you again,
Daniel P
- timi
- Posts: 29
- Joined: Tue Jan 10, 2012 10:35 am
Re: USB LiIon/LiPoly charger, charging calculation
is there a 1mAh battery ?
for example if you charge a battery that is 1000mAh with 500mA then it would take 2h to charge in ideal condition, usualy the efficiency loss is ~10-30% so expect more than 2h ...
for example if you charge a battery that is 1000mAh with 500mA then it would take 2h to charge in ideal condition, usualy the efficiency loss is ~10-30% so expect more than 2h ...
- adafruit_support_mike
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Re: USB LiIon/LiPoly charger, charging calculation
I sincerely doubt it. Even the smallest hearing aid batteries are good for 60-80mA/hr.timi wrote:is there a 1mAh battery ?
For power levels that low, you're getting into capacitor territory. A 1F capacitor will supply 1A of current for 1s, so it will supply 1mA for 1000 seconds. There are 3600 seconds in an hour, so a 3.6F supercap would do the job. It would also have the virtue of almost unlimited discharge/recharge cycles, and would charge to full power in a fraction of a second.
- john444
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Re: USB LiIon/LiPoly charger, charging calculation
Danidub,
First, it is not very good to post in multiple places.
It is confusing and becomes difficult for others to follow the discussion.
"Vreg(Typical)+0.3V" which I take to mean the charger requires 0.3-V over the battery voltage.
So... Again, to fully charge a LiPo to 4.2-V you must input at least 4.5-V.
This charger is not able to boost the input voltage.
Also, I will presume that you intended to express 1-Ahr cell instead of 1-mAhr because you mentioned having a 1,000-mAhr cell in your first post. So... If you are able to supply the 259 with 500-mA it will take slightly over 2-hr. In normal use it will probably be less since it is unlikely that you will start with a fully discharged LiPo.
Good Luck,
and try to keep related topics in a single forum thread.
John
First, it is not very good to post in multiple places.
It is confusing and becomes difficult for others to follow the discussion.
The answer is still the same:danidub wrote:I'm not using the charger id 280, I'm usning id 259 (https://www.adafruit.com/products/259) and in the datasheet is written Vmin 3.75 — Vmax 6. According to this data, it goes again my question:
john444 wrote:The generator will not put any charge into the attached LiPo until the generator's output exceeds the LiPo voltage + 0.3-V.
True. but, that is for charging. Just below the 3.75-V value is the note:danidub wrote: in the datasheet is written Vmin 3.75 — Vmax 6
"Vreg(Typical)+0.3V" which I take to mean the charger requires 0.3-V over the battery voltage.
So... Again, to fully charge a LiPo to 4.2-V you must input at least 4.5-V.
This charger is not able to boost the input voltage.
The data-sheet indicates that the charging current accuracy is about 10% plus the status LEDs. I do not have this model of LiPo charger and I don't have a schematic viewer on his computer. I will guess that the LEDs are pulling about 10-mA each. Only two can be on at a time so the total is about 520-mA +/-10%.danidub wrote:How much current the charger (https://www.adafruit.com/products/259) will draw from my generator? for charging at 500mA
danidub wrote:using this setup, is there a way to calculate or estimate time for charging a 1 mAh LiPo battery?
This is regardless of the LiPo capacity.john444 wrote:The generator will not put any charge into the attached LiPo until the generator's output exceeds the LiPo voltage + 0.3-V. If the LiPo is low you may get some charge but it will taper off as the LiPo voltage increases. The result is: it will never reach full charge and even partial charging times will become excessive.
Also, I will presume that you intended to express 1-Ahr cell instead of 1-mAhr because you mentioned having a 1,000-mAhr cell in your first post. So... If you are able to supply the 259 with 500-mA it will take slightly over 2-hr. In normal use it will probably be less since it is unlikely that you will start with a fully discharged LiPo.
Good Luck,
and try to keep related topics in a single forum thread.
John
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Re: USB LiIon/LiPoly charger, charging calculation
Hello timi!
Thank you!
I'm sorry, it was a 1000mAh battery not a 1mAh, thank you for the calculation, that was something I need!timi wrote:is there a 1mAh battery ?
for example if you charge a battery that is 1000mAh with 500mA then it would take 2h to charge in ideal condition, usualy the efficiency loss is ~10-30% so expect more than 2h ...
Thank you!
Please be positive and constructive with your questions and comments.