DC compressor fridge power usage question
Hey guys - Looking for some help on a fridge topic. First post and have been reading as much as possible on this forum as well as others on the topic... has been very helpful. Quick summary of my ...
Forum Discussion
Hey guys... I appreciate all of the posts. They have been extremely helpful. Just an update. I purchased an Isotherm fridge with the BD35. I'm still working on finalizing the insulation and managed to pack in 300+AH of battery and installed an extra 200W solar. A bit overkill given my small camper, but 300W and 300+AH of battery seems doable based on the data shared.
I got an opportunity for an overnight shakedown test on a campground. Unfortunately I forgot to reset my battery monitor settings so I don't have a good basis on data. However, I learned a couple of things: 1) You really don't get much charging amps under tree cover even at peak solar. 2) The fridge rocks and even gives me quite a bit of extra space over the earlier version 3) When under fully exposed peak solar, I get the full 15A from my PWM 15A controller and it really charges the batteries back up quickly. With many of my camping spots being under cover, I'll just make an extra effort to head out to a clearing during peak solar to recharge. 4)I need to do some baseline testing in addition to completing insulation. I may even camp out in my driveway to get a more realistic scenario.
I did run the setup in my shop the other night and started tracking the data. It's not heated, but I'll bet it fluctuates between 50-70deg F throughout a 24hr cycle. Since running inside there is no auxilliary power from solar so truly running off battery. I was able to run 3full days and averaged the first two days at 1.7A with the three day total at 2.2A. This tells me ambient swings play a large role and additional insulation should improve those numbers. I had AH to spare and was roughly at 14% remaining (that is 57% total capacity to prevent my flooded batteries from damage). Of course I only opened the fridge once per day to grab a coke and I only had an inverter going to run a timer clock as well as the camper sensors. So it's not necessarily realistic from a perspective of actual operation.
As a summary, I am able to get 3days off of just battery and my even improve that with better insulation. It would also be possible to sustain given that I'm conscious of getting line of sight to the sun for my panels.
The unfortunate things is that after I dropped $1200 on the fridge, the test engineers that I work with all have similar models of BD35 compressor fridges at their desks. Working at a heavy truck OEM, when they scrap test trucks, they take out useful items and I could have obtained one for free. Oh well.
Thanks again for all of your input.
I got an opportunity for an overnight shakedown test on a campground. Unfortunately I forgot to reset my battery monitor settings so I don't have a good basis on data. However, I learned a couple of things: 1) You really don't get much charging amps under tree cover even at peak solar. 2) The fridge rocks and even gives me quite a bit of extra space over the earlier version 3) When under fully exposed peak solar, I get the full 15A from my PWM 15A controller and it really charges the batteries back up quickly. With many of my camping spots being under cover, I'll just make an extra effort to head out to a clearing during peak solar to recharge. 4)I need to do some baseline testing in addition to completing insulation. I may even camp out in my driveway to get a more realistic scenario.
I did run the setup in my shop the other night and started tracking the data. It's not heated, but I'll bet it fluctuates between 50-70deg F throughout a 24hr cycle. Since running inside there is no auxilliary power from solar so truly running off battery. I was able to run 3full days and averaged the first two days at 1.7A with the three day total at 2.2A. This tells me ambient swings play a large role and additional insulation should improve those numbers. I had AH to spare and was roughly at 14% remaining (that is 57% total capacity to prevent my flooded batteries from damage). Of course I only opened the fridge once per day to grab a coke and I only had an inverter going to run a timer clock as well as the camper sensors. So it's not necessarily realistic from a perspective of actual operation.
As a summary, I am able to get 3days off of just battery and my even improve that with better insulation. It would also be possible to sustain given that I'm conscious of getting line of sight to the sun for my panels.
The unfortunate things is that after I dropped $1200 on the fridge, the test engineers that I work with all have similar models of BD35 compressor fridges at their desks. Working at a heavy truck OEM, when they scrap test trucks, they take out useful items and I could have obtained one for free. Oh well.
Thanks again for all of your input.
