A yellow battery light on a hoverboard is the same as an orange light on a hoverboard.
In short, a yellow flashing light on a hover board means that the battery is bad or going bad. This typically happens after 6-12 months of use.
Other occasions where a hoverboard has a solid or blinking yellow light is when a hoverboard has sat too long before it was sold. Hoverboards are all manufactured in China (no matter the brand) and they can be months to years old by the time you purchase it.
When confronting a yellow light on your hoverboard, the only way to fix it is to buy a hoverboard battery replacement.
Q. When I plug in my Hoover board I get a yellow blinking battery light. It never progresses past that to a full charge. I assume it’s a bad battery. What do you think?