Thank you for your feedback on the replacement battery that you ordered. It is definitely a possibility that your unit may have an optional battery compartment for an additional battery which would be needed to extend the illumination duration. However, we would need more information about your Gama Sonic model.
Please reach out to our support team at your earliest convenience so that we can look into this issue further with you. Our support team is available M-F; 9:00 am to 5:00pm EST.
We look forward to hearing from you.
GS Support Team
1-800-835-4113