You should have a battery recycling program with your city or county. Otherwise, certain battery stores, such as Batteries Plus, will take them to be recycled at no cost.
If you have a volt meter/multi-meter, use it to easily tell which is not working.
Otherwise:
-If the battery seems to get some charge, like working for a few minutes after a 18-30 hour charge, but then running out of power, then it's an issue with the battery. There is probably a dead cell inside the battery which cannot be fixed. A replacement battery is warranted.
-If the battery won't charge at all, and it doesn't get warm after a few hours on the charger, then it's likely the charger. A replacement charger is warranted.
These lead acid batteries are the same kind as your car battery. If you do not start your car for a few months, the battery will be dead. It states in the charging instructions that come with each battery, to not leave without a charge for more than a month. The best that can recommended is to try charging uninterrupted for 30 hours. This might restart it. Otherwise, you will need to buy a new one and this is not covered by the warrenty.
If this was fulfilled by Amazon, they do not accept this type of battery as a return. You may contact them to see if they will still give you a refund.
If this came directly from the reseller, contact them for troubleshooting. If there is nothing wrong with the battery, and a return is still desired, you are responsible for the return shipping. USPS Flat Rate boxes or envelopes are the least expensive.
If the battery was charged for the correct amount of time, it's rare, but possible that you received a defective battery. Contact the reseller for a replacement.
It's a good idea to use a single piece of electrical or duck tape to hold the wires down to the battery itself. That will keep the wires on the terminals in tact, as these usually break from being knocked around.
Please make sure your ride-on toy has the 2 pins red connector as shown in the picture to make sure our connector is compatible.