Hi all wanting some help confirming a battery charger circuit using TP5100. Also, can anyone explain the RTS resistor value in the datasheet schematic? Thanks in advance.

 

RTS & RTC form a Voltage-Divider using the Regulated-Voltage as a supply.
There are Hot and Cold Temperature-Limits,
less than ~45% of V-Reg is Off due to too Hot Battery-Temp,
more than ~80% of V-Reg is also Off due to too Cold Battery-Temp.
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Thank you for the reply mate that does make sense now is RTC the same as NTC? what are the abbreviations?

 

Sometimes You run into completely "made-up" Acronyms, RTS is one of them.
RTS probably stands for Resistor,...... ( for the ), ...... Temperature-Sensor.

However, NTC is common, and stands for "Negative-Temperature-Coefficient",
which means it's a special Resistor that changes it's Resistance based on Temperature,
the Resistance will go down as it's Temperature rises.
There are also Positive-Temperature-Coefficient-Resistors, but they are much less common.

Lithium-Based-Cells are Temperature-Sensitive, so a Battery-Temperature-Sensor is a good idea.
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Ok got it and yes I think many terms in electronics seem to be made up and don't make sense at times.

Looking at my circuit I think it looks correct but need to doublecheck value of the RTS value in regards to the temperature.

Thanks once again.

 

Hi mate one more question for the battery sens I am using ESP32 should I make the voltage divider values for R18 and R19 27K and 100K so the signal is 3.3V with the current setup signal would be 2.1V when the battery is fully charged to 4.2V

I want to show with LED when the battery is fully charged and also when the charge is low (below 3.5V) the module will turn off at 3.2V for cell voltage dropout.

 

... should I make the voltage divider values for R18 and R19 27K and 100K so the signal is 3.3V with ... the battery is fully charged to 4.2V...

Better to consider that the micro's analog inputs will be saturated when you get to the full scale of the ADC. And keep in mind that a 3.3V reference (supply?) has a tolerance, and could be some percentage lower than 3.3V. Scale your input to not exceed maybe only 90% of that lowest reference value.

 

Hi @trav333, did your circuit worked?