A budget tp4057 based charging circuit

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FearOfTheDark
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A budget tp4057 based charging circuit

While tp4056 based circuits are widely available and super cheap (less than 0.5 USD including shipping), tp4057 circuits are rare and about 8 times more expensive.
Do you know where can I get a cheap tp4057 based circuit (about 1 USD)?

Edited by: FearOfTheDark on 05/02/2021 - 17:10
Sunnysunsun
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What benefit does it have over the 4056?

FearOfTheDark
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Reverse polarity protection

tech
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I have seen several of these circuits for 2$ US on Aliexpress. still more than 50¢ but available.
While reverse polarity protection is a nice features, these boards are often soldered into arduino projects, hobby tools and RC, et al. They could have lithium cells that are a more permanent part of the setup (non removable, or with special connectors) or the entire cell is difficult to reverse.
But I do understand the need for the feature on other circuits.

FearOfTheDark
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tech wrote:
I have seen several of these circuits for 2$ US on Aliexpress

The Cheapest I Can find on Aliexperss is 4.31 including shipping Sad

It is for a project including a removable 18650 so I do need the reverse polarity protection

tech
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https://s.click.aliexpress.com/e/_9zTTp5

https://s.click.aliexpress.com/e/_AKz7Lh


10 for 11 dollars, 6 after coupons if you have any.

If you are a new user, click on https://a.aliexpress.com/_mri2XNp to get coupons.

Sunnysunsun
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Are you sure the 4057 has battery side reverse polarity protection? I can’t read Chinese but it seems quite rare and expensive when filtering for chips with battery side reverse polarity protection on Digikey that I resorted to looking for an alternative method such as a resettable ptc fuse. Power supply side reverse polarity protection is common, battery side is not.

Lightbringer
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Yeah, it’s kind of assumed the cell is going to be soldered-in, correctly, like for a powerbank or other doodad, and not be removable.

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FearOfTheDark
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Sunnysunsun wrote:
Are you sure the 4057 has battery side reverse polarity protection? I can’t read Chinese but it seems quite rare and expensive when filtering for chips with battery side reverse polarity protection on Digikey that I resorted to looking for an alternative method such as a resettable ptc fuse. Power supply side reverse polarity protection is common, battery side is not.

Google translate says “Adopt SOT23 package 500㎡A anti-reverse connection charger for lithium battery” so I think it has reverse polarity protection

Sunnysunsun
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Yes but the tp4056 also has anti reverse/reverse polarity protection but that’s at the power source only, not battery side rpp.