My Li-ion batt. measures 114mm long, 70 wide and 40 thick with the velcro that holds it in and it's a snug fit. Close as I can get for the compartment is 130 long but there's a small half former to brace the undercarriage that's 100 mm back from the firewall. My batt just slips under it. 80 mm wide and 50mm deep. Hope this helps.