BQ25185: ILIM/VSET Resistor

Part Number: BQ25185

Tool/software:

Hello, for my application there will almost always be a source connected to the Vin pin of the BQ25185 charger. I don't want it always trying to charge my secondary battery as soon as the voltage drops below its max voltage. Is there any wiggle room to get a resistor value that will get a VBATREG not listed on this table shown in the datasheet? For clarity, my battery has a max voltage of 4.1V. I would prefer not to have the charger always trying to charge it to 4.1V. Instead, I would like to charge to a voltage like 3.9V that way my battery can sit without being charged as often. My application has this charger acting standalone so there would not be a microcontroller that could control the /CE pin.

Any help would be appreciated. Thank you!




  • Hello,

    Thanks for reaching out.

    There aren't any other VBATREG options other than those that are shown in Table 8-1. However, the BQ25185 has a recharge threshold (VRCH, 100mV typical), which is the amount that the BAT pin voltage must drop below the battery regulation voltage (VBATREG) before a new charge cycle is started. For example, if the battery was charged to 4.1V, it would have to drop to 4.0V before it started charging again. Would this work for your application?

    Best regards,

    Alec