I've had a 2007 Coleman Fleetwood Cobalt pop-up camper for about 6 months now. I've put in new batteries and everything worked great for 3 trips. On the fourth trip, there was no electrical in the camper (lights, heater, outlets) and then my batteries went dead (gas alarm went off). So, I've always kept my batteries charged. although my charger never stops flashing which would indicate that the battery is full. I've replaced all fuses and I replaced the switch under the sink that activates all electrical when you set the camper up. I've checked all connections and looked for wire damage. While I did find a mouse nest under one battery lid, there is no indication of any damage. Thanks for any help.