? On dry camping for 2 nights propane use?

Well.just to get a better handle on things I went out and weighed my propane tanks this morning.i was way off by guesstimating by picking up the tanks as to real time weight. A 20pd lp tank full is @ 38 pds so with that in mind I weighed both tanks 1 tank was at @ 27pds +-2pds. Which would give me 27pds-18pds(propane tank weight)=@9 pds of lp left.tank 2 is still at @38pds .so apparently I still have 1 full tank and the other tank is 1/2 full. As for propane I have plenty.i will weight the tanks everytime instead of estimating by lifting method.lol.i know I have plenty of lp because I figured what I used last week for one night of dry camping last week before we went to a full hook up site.temp were the same as they forecast it will be the days we dry camp coming up.as for everyone worried about the battery.read my earlier post .besides the furnace use at night which starts at @ 9:30 pm to 8am the next morning .dry camping is conserving everything is limited use .battery operated lanterns powers the light most of the time.and the water heater is only used for dishes and a shower or two more showers=cg shower facilities.so like I said I was still at 2/3 battery the next day by noon.i should have no problems for 2 days dry camping.but we will see.definatley good for one night.might I ad that I only have a 17ft hybrid not a 24+ ft or 5th wheel!