Trojan battery charging advice please

[Mike90250]

for 2 weeks, just buy some dry ice now, and again in 6 days. 10 pounds should be enough if the freezer is already cold

[J.P.M.]

STOP.

I seriously doubt it uses 2.4 Kwh per day unless this is a 1950's model freezer. Yes it tmay use 100 watts running, but it does not run all day. You did this wrong with your Kwh meter. To get accurate it needs to run a week. Example start today at say 6:00 pm. Let it run one week util 6:00pm. Say it reads 7 Kwh/7 days is 1 Kwh per day. Otherwise you are going to eff yourself out of a lot of money. .My educated guess which is pretty good is it use less than 1 Kwh per day. Only way you are going to know is a long term test.

FWIW, I've got a side/side fridge/freezer (GE) in the garage that's about 10 yrs. old and in decent shape. I only use it when some folks stop by for about 3 weeks or so 1X/yr. I've got a kill-a-Watt meter on it w/ thermometers in the fridge portion ( ~ 42deg. F) and freezer ( ~5-10 deg. F.). This year it was on from 11/18/2015 @ 0615 hrs. to 12/13/2015 @1900 hrs. The kill-a-Watt meter showed it had burned through 34.49 kWh in that time (~ 636 hrs.) So, 34.49/636 ~ = .054 kWh per hr., or ~ 1.3 kWh/day. The ice cream didn't melt and the beer/N.A. slop and mass quantities of food stayed cold. The garage ambient was ~ 65-70 deg. F. or so most of the time w/ a few excursions of a few degrees F. in both directions.

[smily03]

(I know this is an old thread, but thought this could help too...)

Something that can be more helpful than a kill-a-watt meter is to do something like building your own openenergymonitor box. Really simple to do. You can send the data to their open-source emoncms software, and keep track of the frequency of the runs, etc.

This is the chart for our two deep freezes over a couple of days. Both hold about -5F. The big peaks with long, less-frequent runs are the freezer that holds meat and other dense foods, while the shorter, more frequent spikes are for the freezer that holds bread and stuff like that.

Then you can do stuff like data aggregation, etc. to get your usage per day.