Veraxis
Active Member
Hello all,
I recently bought a set of protected 18650 cells (I bought them here: https://www.amazon.com/gp/product/B00O8U187W. They are say they are based on the specifications of the unprotected cell found here: https://www.tme.eu/en/Document/40f2659afab69dbec94c09cc473a0e25/ICR18650-26F.pdf.) Seeing them in person, they appear of good packaging and quality and do appear to have the proper protection IC and gas vents, so I have no reason to believe that they are among the many Chinese knockoffs that are everywhere on the internet. I may perform tests later if deemed necessary.
More to the point, the protection circuit in each cell supposedly protects against over-charging/over-current, so does this mean that I can use a simpler charging circuit, rather than the more complex charging scheme for unprotected cells? (see: **broken link removed**). For example a simple constant-current or constant voltage circuit using a transistor? (see schematics). or would it still be advisable to have some kind of feedback mechanism to stop the charging once a certain charge voltage has been reached? (see other schematic).
At a more basic level, if the cell is protected, is it safe to rely on that circuitry to stop the charging once the cell is fully charged, or should I still be using a full multi-staged charging scheme as would be necessary for an unprotected cell? Are "protected" cells meant to effectively have the charging circuitry built-in, or is this merely a failsafe for worst-case-scenario failure of the charging hardware? I have relatively little experience with rechargeable batteries, so any advice you could provide would be appreciated.
I recently bought a set of protected 18650 cells (I bought them here: https://www.amazon.com/gp/product/B00O8U187W. They are say they are based on the specifications of the unprotected cell found here: https://www.tme.eu/en/Document/40f2659afab69dbec94c09cc473a0e25/ICR18650-26F.pdf.) Seeing them in person, they appear of good packaging and quality and do appear to have the proper protection IC and gas vents, so I have no reason to believe that they are among the many Chinese knockoffs that are everywhere on the internet. I may perform tests later if deemed necessary.
More to the point, the protection circuit in each cell supposedly protects against over-charging/over-current, so does this mean that I can use a simpler charging circuit, rather than the more complex charging scheme for unprotected cells? (see: **broken link removed**). For example a simple constant-current or constant voltage circuit using a transistor? (see schematics). or would it still be advisable to have some kind of feedback mechanism to stop the charging once a certain charge voltage has been reached? (see other schematic).
At a more basic level, if the cell is protected, is it safe to rely on that circuitry to stop the charging once the cell is fully charged, or should I still be using a full multi-staged charging scheme as would be necessary for an unprotected cell? Are "protected" cells meant to effectively have the charging circuitry built-in, or is this merely a failsafe for worst-case-scenario failure of the charging hardware? I have relatively little experience with rechargeable batteries, so any advice you could provide would be appreciated.
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