Trying to get the most out of the TV alternator

[tinkeringtechie]

[quote source="/post/1788/thread" timestamp="1404252840" author="@mitch"]The fridge will use about 12 amp hrs per day by my figuring. [/quote]This is due to the fridge frame heater. I wasn't willing to give up that much juice for a feature that isn't useful in my climate. Here's my quick fix:

http://livinlite.proboards.com/thread/144/fridge-frame-heater-switch

I actually disconnected it a few trips ago and haven't noticed a difference (except in my increased battery life). I may still add the relay eventually, but for now I'm just leaving it disconnected.

[david]

Mitch:

Yes I would appreciate that reference to 12 amp hours for the fridge. 12 AH in 24 hrs is amazing. And so far we haven't used the fridge. It takes too long to cool down for an overnight or two so we use a cooler with ice.

I have no way of actually measuring it other than instantaneous amperage. On a prior camper I had a battery monitor that integrated actual amphours used. That was before LED lights and we probably used 20 or so AHs each day.

But I have measured battery voltage and it hardly drops after 24 hours, so it can't be that much without the fridge.

David

[mitch]

[quote source="/post/1791/thread" timestamp="1404253753" author="@david"]Mitch:

Yes I would appreciate that reference to 12 amp hours for the fridge. 12 AH in 24 hrs is amazing. And so far we haven't used the fridge. It takes too long to cool down for an overnight or two so we use a cooler with ice.

I have no way of actually measuring it other than instantaneous amperage. On a prior camper I had a battery monitor that integrated actual amphours used. That was before LED lights and we probably used 20 or so AHs each day.

But I have measured battery voltage and it hardly drops after 24 hours, so it can't be that much without the fridge.

David[/quote]Sorry, I don't recall my exact reference for the fridge I found it a while ago, but this is the basis of my total amp draw



[span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    Hours[span]    [/span][span]    [/span][span]  Daily [/span][/span][span]    [/span][span]    [/span][span]    [/span]
[span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span]
[span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span]Volts[span]    [/span]            Amps[span]    [/span]          Watts[span]    [/span]         Use/Day[span]    [/span]          Amp Use   



Lights [span]    [/span][span]    [/span][span]    [/span][span]    [/span]                   12 [span]    [/span]               1.20 [span] [span]    [/span]   [/span]            14.4[span]    [/span][span]    [/span]         2[span]    [span]    [/span][span]    [/span][/span]                      2.4 [span]    [/span][span]  [span]    [/span][span]    [/span]  [/span]          Four, 3.6 Watt LED bulbs   



Furnace[span]  [/span][span]    [/span][span]    [/span][span]    [/span]                 12  [span]    [/span]               3.40 [span]    [/span][span]    [/span]            40.0[span]    [/span][span]    [/span]         0[span]    [/span][span]    [/span][span]    [/span]                      0.0   



Refrigerator [span]    [/span][span]    [/span]12 [span]    [/span]                 0.50[span]    [/span][span]    [/span][span]    [/span]               6.0 [span] [/span][span]    [/span]           24 [span]    [/span][span]    [/span][span]  [/span] 12.0[span]    [/span][span]    [/span][span]    [/span][span]    [/span]          On propane mode w/electronic control panel   



CO Monitor [span]    [/span][span]     [/span]            12 [span]   [/span][span]  [/span]0.11[span]    [/span][span]    [/span][span]    [/span]              1.3 [span]   [/span][span] [/span]           24[span]    [/span][span]    [/span][span]    [/span]                     2.6   



Smoke Detector[span]   [/span]      12[span]    [/span]                   0.00[span]    [/span][span]    [/span][span]    [/span][span] [/span]              0.0[span]     [/span]         24[span]    [/span][span]  [span]     [/span]  [/span]0.0   



Water Pump [span]    [/span][span]    [/span]          12[span]    [/span]                 4.00 [span]    [/span][span]    [/span]           48.0[span]      [/span]        0.5[span]    [/span][span] [span]     [/span]  [/span]                    2.0   


 
Water Heater[span]    [/span][span]    [/span]          12[span]    [/span]                0.20 [span]    [/span][span]    [/span]             2.4[span]      [/span]         0.75[span]    [/span][span]    [/span][span]    [/span]                  0.2   



                                                                             [span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span][span]    [/span]Total AHr Draw/Day [span]    [/span]19.2

[charliem]

[quote source="/post/1791/thread" timestamp="1404253753" author="@david"]Mitch:

Yes I would appreciate that reference to 12 amp hours for the fridge. 12 AH in 24 hrs is amazing. And so far we haven't used the fridge. It takes too long to cool down for an overnight or two so we use a cooler with ice.

David[/quote][font size="3"][font face="arial"]The fridge actually uses a bit more than 12 AH/day. According to my conversation with Dometic the frame heater alone uses 0.5A (6 watts) continuously from the battery. They used to provide a switch for it, but for some reason they no longer do. My guess is dollars or customer confusion. My current measurements confirm their numbers. I'm going to install a switch too until I discover I never need the heater anyway. [/font][/font][font size="3"][font face="arial"]In addition the fridge requires DC current to open the gas valve when cooling plus current to run the logic and light the interior lamp when the door is open. All in all the minimum DC current draw is 1.0 Amps just to keep the trailer alive![/font][/font][font size="3"][font face="arial"] [/font][/font]

[charliem]

[font size="3"][font face="arial"]I went back and looked at some of my notes. As posted [a href="http://livinlite.proboards.com/thread/134/minimum-battery-load-21rbs"]Here[/a] the minimum current draw is 1.0 Amps or 24 AH per day and that's before any lights, heat, fans, or cell phones. Just fridge, propane detector, WH logic, maybe furnace logic, radio, etc. Two days and you've dumped 1/2 of the standard group 24 battery.
[/font][/font]

[mitch]

I've been looking pretty hard at all the manuals for the Dometic RM-2554 and I see no reference to a frame heater or anti-condensation device at all.  Is it possible that this model, which is in my 13QBB, doesn't have a frame heater?

[tinkeringtechie]

[quote source="/post/1796/thread" timestamp="1404307618" author="@mitch"]I've been looking pretty hard at all the manuals for the Dometic RM-2554 and I see no reference to a frame heater or anti-condensation device at all.  Is it possible that this model, which is in my 13QBB, doesn't have a frame heater?[/quote]I just looked over the schematic for you model and it doesn't have the frame heater.

[mitch]

[quote source="/post/1799/thread" timestamp="1404309726" author="@tinkeringtechie"][quote source="/post/1796/thread" timestamp="1404307618" author="@mitch"]I've been looking pretty hard at all the manuals for the Dometic RM-2554 and I see no reference to a frame heater or anti-condensation device at all.  Is it possible that this model, which is in my 13QBB, doesn't have a frame heater?[/quote]I just looked over the schematic for you model and it doesn't have the frame heater.[/quote]Thanks

[david]

I was puzzled about what was a "frame heater"? Defrosting?? So I googled the term. It is to keep the edge of the freezer compartment door from freezing shut to the frame. Since my fridge (in a 16TBS) does not have an exterior freezer door- it is inside the refrigerated compartment, I suspect that models like this one (don't have the model number, the unit is in a storage yard) do not have a frame heater. That is why the unit in the 13 reported above doesn't have a frame heater either.

David