BQ25504-Evaluation Kit

Dmitry Chikov

I ve got BQ25504EVM (Evaluation Kit).

With no changes, I connect it to solar panel ->got 3.1~3.2 V -works great!

But when I use super capacitor to J2(BAT/GND) voltage goes down to 1 V and doesn't matter what I do with solar panel - it stays 1.080V.

What I do wrong???

over 12 years ago

0 Jeff F over 12 years ago

TI__Guru**** 166176 points

When you connect the super cap, what is the voltage on VSTOR? Try completely disabling the charger with VSTOR at 0V then connect super capacitor and then repower the IC. It should eventually charge the super capacitor.

0 Dmitry Chikov over 12 years ago in reply to Jeff F

Prodigy 40 points

ok now it works.

0 Jeff F over 12 years ago in reply to Dmitry Chikov

TI__Guru**** 166176 points

Super caps have higher leakage currents than regular capacitors. It is possible that the super cap leakage current loads the charger so much that it cannot provide both the load current and charge the super cap. What is the output power capability (or Isc and Voc) of your solar cell at your lighting conditions?

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BQ25504-Evaluation Kit