Searching a 2 cell Li-ion battery charger chip

Battery Management
#1

Hi, Mps Teams:

We have a new project, which needs a new battery charger chip for a 2 cell serial system:

  1. input voltage: we want to use DC 12V as the input
  2. for the control signal: the standalone will be ok if it is about I2C, it will be better
  3. we want the chip to have over-current, over-voltage, and temperature protection functions.

Right now, I look at the MP2615 and MP2615A chips, I have some questions:

  1. which one is better? what is the difference between them?
  2. whether this chip has over-voltage and over-current protection, should I need to add another protection chip (such as a DW01 chip and others).
  3. should I also add some balance chip for the 2 cell charge(such as BQ29209)?
#2

Hi justinekongjie,

Thanks for your question.
The difference between the two parts is the full battery voltage rating. MP2615A has a 4.2 V/Cell and 4.35 V/Cell selection, MP2615 has a 4.1V/Cell and 4.2V/Cell selection. As for which one is better, it just depends on your application.
There is over-current and over-voltage regulation on the chip that maintains highly accurate constant voltage and current charge. Refer to page 13 of the datasheet for more information. Because it has this regulation feature, I don’t believe it is necessary to add an additional protection chip.
If you want to have cell balancing in your design, then yes, you’ll need to add an external chip to enable that feature. This part does not have cell balancing.

Thanks,
Cindy

#3

Cindy, we are redesigning a board because our 2S charger component had come to end-of-life. I have studied the MP2615 and it will accomplish what we need. My question is related to the long-term production stability (is it approaching end-of-life?) and availability (lead times?). Can you provide any comforting news regarding these two issues before we commit to a new design?

Thank you.
JS

#4

Cindy, a few more questions please:

  1. Input voltage max for vSEL (terminal battery voltage select) is defined as 6.0 v. If I am charging a 2S battery, my input voltage to the system will be 9.0 volts to 10.0 volts (to minimize power drop across the MP2615). I will not have 6.0 volts or less to control the vSEL input pin. Am I incorrect in assuming that all values are multiplied by 2 when using a 2S pack? For example, the terminal battery voltage is defined as 4.2 when vSEL is 4.0 volts (MP2615A). With a 2S system the terminal voltage will be 8.4v. May I assume that I can pull the vSEL pin to + input voltage for the charge chip (9 or 10 volts in)?

  2. My cursory review reveals that the footprint is the same for both components (MP2615 and -A). Hence, are they interchangeable save for the choice of pulling up or down the vSEL pin? If I always want 4.2v per cell, then I can substitue the componet based upon which is available and design a jumper that is stuffed appropriately for my 4.2v choice?

Your expert advice is greatly appreciated.

JS

#5

Hi there,

It seems we might be able to help you better if you contact us directly through MPSNow:
https://www.monolithicpower.com/contact/mps-now-technical-support.html

Thanks,
Cindy