Is current draw from a bilge pump an issue? I would assume that if the house batteries are being topped up via solar or wind, that with a long term unattended boat the engine battery could be drained by a pump running, whereas the house bank would automatically be getting topped up? Can house battery banks sustain a bilge pump for 2, 3 or 4 weeks?
Good question, a bilge pump might draw 5 to 15 amps at 12 VDC, over multiple 24 hour periods. Most boat batteries would only last a few days or maybe a week depending on the size of the bilge pump and the battery bank size and health.