Razor e300 batteries are bulging. Is that normal?

Bulging battery means u have to replace it, the plates started to oxidize and pushes the everything out!

Replace these batteries asap.

Battery Troubleshooting Guide 101 Why Do Lead Acid Battery Swell Up

E300 Razor Electric Scooter Battery Set 2 batteries 12V 7 5Ah

Swelling batteries are extremely bad.

Sealed Lead Acid Batteries will generally stay cool, and retain their shape, but if any overcharging, overheating, or aggressive shaking occurs, the batteries can EXPLODE. The batteries will literally EXPLODE if you allow them to overheat, and swell beyond the batteries capacity. The swelling or bulging that you are seeing is potentially dangerous, and needs to be addressed by a skilled professional, as the batteries could be so swollen that they are ready to explode ANY SECOND. Like a water balloon, the batteries will swell and swell, until something restricts them, or the battery housing lets go.

If you are looking for replacement batteries for your scooter, you can check out this very helpful Chinese Scooter Replacement Store Online.
http://www.partsforscooters.com/s.nl?partner=URBANSCOOTERS

-Jackson
http://urbanscooters.com/