How to access/remove house battery?

[chc59]

2006 Four Winds Chateau Sport 28a
I've had this RV for about a year. My first. I may need to replace the house battery, or at least check the water level. I cannot figure out how to remove/access the battery. It is in a plastic tub. I removed the tub cover by releasing the buckle on the strap securing the cover. I thought that the battery tub would slide out once I removed the bar across the end. If it does slide out, I am at a loss. Tub does not move. Cannot see any securing hardware. Manual does not help. Is the access from above from inside the coach?

Battery is not holding a charge even when being charged by an external charger. Don't know age of the battery. I used the furnace all night recently. Battery was dead by morning.

Any recommendations for a replacement if I need to do so?

Appreciate your help/advice.

Joe

[be happy]

I would say that if you have not in at least a year checked the water lever of the batteries they must be in need of water. However by this time they may also be totally gone

If there is room to unhook the battery and lift them out of the plastic tub that would be a start. I can not imagine an access from above.
Good luck