It is the electric scooter charger that you found on eBay.
Qili Power, Class 2 Charger Model QL-09005-B2401500H.
Input AC 100-120V 50/60Hz 1.5 A
Output 24V 1500 mA
Charger only 12V Lead-acid Rechargeable Batteries, other type of batteries may burst causing injury to persons damager (Made in China).
Green - charged OK
Red - charging

Testing the posts of the battery now charging, I get 5.9-7.1 so it is going up some. The other battery that charged up to green but read 18 instead of 24 was only very, very slightly warm. The original specs on the battery said it took a full 24 hours for each recharge.