Namaste, iam Gregory Noeldner, May your day be joyful.
How Do Battery Vent Caps Work? [Solved]
As the battery stops gassing and the cap cools, water vapor condenses on the walls of the plug and will flow back into the battery, thus 98% of the hydrogen/oxygen gas mixture generated during charging will be recombined and converted back to water.
Off-Grid Solar Power Battery Vent Caps
This video is about the Water Miser
Battery Safety: How does a bottom vent help against exploding batteries? (18650, 21700, vent)
Lithium ion batteries
Battery Vent Tube Testing - The Battery Shop
Although this video may provide you with the basic procedures for inspecting and testing the