COUP-DE-FOUET (Battery phenomenon)
Well when I first started testing my AGMs, I found a tiny voltage drop and then slight recovery of voltage when first applying a constant heavy load. I wondered if it was just variation in my instrume...
Forum Discussion
I first observed this phenomenon in the '60s, so just to satisfy my own curiosity, I did some experimentation.
My observations:
My observations:
- When a heavy load was applied, tiny bubbles would form on the plates.
- The bubbles would reduce the plate area exposed to the electrolyte.
- This would increase the internal resistance of the cell.
- The increased internal cell resistance would cause a brief drop in measured output voltage.
- After a short time the tiny bubbles would come together making larger bubbles.
- This would allow more plate area to come in contact with the electrolyte.
- This reduced the internal cell resistance, allowing the measured cell voltage to return to 'normal'.
