BQ24650EVM-639: BQ24650EVM load on VOUT pin

fabian salinas lopez

Part Number: BQ24650EVM-639

hi,

is it possible and safe to connect part of my system requiring a fixed voltage to VOUT pin while at the same time having a 11.1V battery being charged from that same pin? I know there is a VSYS pin to connect a load/system there, but I'm getting close to 18V from that pin, and the voltage from VOUT is closer to what we need without the need of adding a buck/boost regulator

greetings,

over 5 years ago

0 Jing Zou over 5 years ago

TI__Mastermind 19430 points

The voltage is going to changed with the battery if you are connecting the system in parallel with the battery. It is not going to be fixed voltage

0 fabian salinas lopez over 5 years ago in reply to Jing Zou

Prodigy 60 points

but if the load is in parallel with the BQ24650EVM and to the battery like this:

wouldn't I be getting a fixed voltage? Or at least that's what I understood from https://www.quora.com/Is-it-possible-to-charge-and-discharge-a-battery-at-the-same-time

0 Jing Zou over 5 years ago in reply to fabian salinas lopez

TI__Mastermind 19430 points

When an uncharged battery is plugged in, battery voltage is going to be charged up. If the load is in parallel with the battery, then the voltage will follow the battery voltage

0 fabian salinas lopez over 5 years ago in reply to Jing Zou

Prodigy 60 points

Jing, I greatly appreciate your answers, but I didn't quite understood this last one. By connecting the load like in the schematic, I won't be having a fixed voltage? I thought the load in parallel (like in the schematic) would be seeing the charger's voltage, and if there is no sun to power the solar cells feeding the charger, the load would be seeing the battery's voltage

0 Jing Zou over 5 years ago in reply to fabian salinas lopez

TI__Mastermind 19430 points

Fabian,

When you have the input source connected, do you expect to charge up the battery voltage? If the battery is been charged, the then battery voltage is going to increase up. There is CC and CV stage for battery charging. In CC mode, the output voltage of the charge is not regulated.

Power management

Power management forum

BQ24650EVM-639: BQ24650EVM load on VOUT pin