Battery and furnace - do I expect too much?

[gbaglo]

We're boondocking in the wet, cold and wind.

Original battery wasn't holding a charge. Bought a new battery yesterday. A Trojan 225 27 TMX 12v deep cycle. Lordco said it comes charged but could use a top up, so I plugged the trailer into my Honda 1,000 and ran it for an hour. Battery monitor said good. Used the furnace most of the afternoon so I plugged in to the genset for another hour at dinner. After three hours unplugged and with the furnace in use, the battery monitor had dropped from good to fair.

Is that what I should expect? I paid $220 for the new battery. One better goes for $298. I’m wondering if I should try to return it and get the better one? Or, should I just expect to use the genset to charge the battery from time to time when using the furnace? And, maybe I shouldn't worry too much about the battery dropping into 'fair' zone on the monitor?

baglo