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Adafruit USB Li-Ion/LiPoly Charger - v1.2
Moderators: adafruit_support_bill, adafruit

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Re: Adafruit USB Li-Ion/LiPoly Charger - v1.2

by Alli on Mon Jul 22, 2019 1:10 pm

So are you are saying is that when the battery is fully charged by the charger controller and the voltage is measured to be below 4.2V, the battery is still fully charged ?
I see the charger controller indicate a charge complete status and thereafter a few minutes (approx 30 mins) the battery voltage drops to 4.09V and the charger controlller's charge status changes to 'charging' and then reaches complete charge etc. This only happens when my hardware is cycling in and out of power save mode. When the hardware's current draw is maintained i.e. no power save mode cycling, then the charger controller's charge indication remains on charging and the voltage of the battery remains fixed at the maximum voltage i.e. 4.2V. With power save cycling, it seems as if the battery is reaching fully charged status and then the charger controller is cutting the charging process off and the battery is feeding into the load in spite of the fact that the charger is connected to charger controller?

Alli
 
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Re: Adafruit USB Li-Ion/LiPoly Charger - v1.2

by adafruit_support_mike on Mon Jul 22, 2019 10:06 pm

Alli wrote:So are you are saying is that when the battery is fully charged by the charger controller and the voltage is measured to be below 4.2V, the battery is still fully charged ?

The LiPo won't be fully charged when the cell voltage is less than 4.2V, but another part of the overcharge-protection circuit lets the LiPo discharge slightly before starting another charge cycle.

You mentioned to voltage dropping to about 4.09V, which is about where a new charging cycle would start. The cycle wouldn't last long, but would take the LiPo back to 4.2V.

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Re: Adafruit USB Li-Ion/LiPoly Charger - v1.2

by Alli on Thu Aug 01, 2019 6:48 am

The LiPo won't be fully charged when the cell voltage is less than 4.2V, but another part of the overcharge-protection circuit lets the LiPo discharge slightly before starting another charge cycle.

You mentioned to voltage dropping to about 4.09V, which is about where a new charging cycle would start. The cycle wouldn't last long, but would take the LiPo back to 4.2V.



This is not the case when the hardware is not cycled in/out of power save mode. It doesn't allow that drop but keeps the voltage at 4.2V. This is normal?

Alli
 
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Re: Adafruit USB Li-Ion/LiPoly Charger - v1.2

by adafruit_support_mike on Fri Aug 02, 2019 12:04 am

If you have a continuous current load on the LiPo, and that load is more than 1% of the constant-current charging level, the charger won't be able to terminate its charging cycle.

The charger will provide enough current to take the LiPo to 4.2V, then will hold the voltage at 4.2V while it provides all the current necessary to run the load.

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Re: Adafruit USB Li-Ion/LiPoly Charger - v1.2

by Alli on Fri Aug 02, 2019 5:17 am

Thanks Mike

Alli
 
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Please be positive and constructive with your questions and comments.