Group 4D vs two group 27

[learning all the time]

I am looking to change my RV house batteries. Just did dry camping and 200 ah lasted about 4 hours. Lights, refridgerator, co monitor, and water pump. I feel like I should have had more out of the batteries. We would wake up and the lights were dim with water pump darn near killing them. I believe I damaged the batteries testing them before going as I wanted to see what they could do. Heres the question: are two group 27 batteries better than 1 4D (possibly Renogy hybrid gel)? I can get the same amp hours and elimate some wiring with the 4D (parallel wires). Also, its a little cheaper. Lithium is not really necessary as I rarely dry camp. Thanks in advance for replies.

 

[Deleted member 165]

Your refrigerator is what killed your battery. Rather than going from feelings, you will benefit greatly from calculating the watt hours of each of your loads, and making sure that your power consumption is less than 50% of the available watt hours in your battery. Start with a power audit, and select your battery based on your needs.

 

[learning all the time]

Thanks Schlagger. I am currenlty waiting on some testing equipment. My refrigerator is only suppossed to take .8 AH in DC mode per the manufacturers sticker. I was estimating running around 5 AH with 200 AH of battery so I should get 20 hours of life. I want actual numbers so I will test the battery with each indivual load on it.

 

[Deleted member 165]

Can you tell us what the make and model of the refrigerator is? Assuming your battery is 12 volts?

 

[mapguy525]

The 4D -if a deep cycle battery, will handle larger loads better than the paired Group 27. That and a bit less cable are the only benefits for the larger battery. Major issue of the 4D is size and weight in regards to handling the battery.

If you have a pair of 27's - you don't have 200AH of useable battery capacity. Lead Acid, AGM, and GEL batteries don't provide 100% of the rated storage capacity as usable. Typically don't want to discharge a LA battery more than ~ 50% on a regular basis -if seeking long cycle count lifetime.

 

[learning all the time]

Schlagger it looks like I have a Norcold N61x model refrigerator that I was running off 12v battery with propane. Apparently, elevation causes more draw and I was about 7800 ft. Also, I ran the unit for 2 days hooked up to my house to cool it before leaving. Testing equipment should arrive today so I will test loading tomorrow most likely. I am also looking into a good DC power monitor but with so many out there research is taking time.

 

[learning all the time]

The 4D -if a deep cycle battery, will handle larger loads better than the paired Group 27. That and a bit less cable are the only benefits for the larger battery. Major issue of the 4D is size and weight in regards to handling the battery.

If you have a pair of 27's - you don't have 200AH of useable battery capacity. Lead Acid, AGM, and GEL batteries don't provide 100% of the rated storage capacity as usable. Typically don't want to discharge a LA battery more than ~ 50% on a regular basis -if seeking long cycle count lifetime.

Thanks MapGuy. The 4D is coming up a little lighter than my current 27's . I have a small storage space next to it I may possible do another and get 400 AH. As soon as I figure out my draw issues I will move forward. I am seeing a possibilty of LifePo4 150 AH fitting needs a little better.

 

[mapguy525]

Schlagger it looks like I have a Norcold N61x model refrigerator that I was running off 12v battery with propane. Apparently, elevation causes more draw and I was about 7800 ft. Also, I ran the unit for 2 days hooked up to my house to cool it before leaving. Testing equipment should arrive today so I will test loading tomorrow most likely. I am also looking into a good DC power monitor but with so many out there research is taking time.

Absorption Refer by that model number. It is more efficient to run using propane over the 12v option. If you want to run on 12v -get a compressor fridge instead. Expensive but efficient use of battery power.