Battery question

[paphil]

Freezer: https://www.amazon.com/EdgeStar-FP43...+freezer&psc=1

CPAP: http://www.thecpapshop.com/philips-r...CABEgLEGvD_BwE

Fan: https://www.amazon.com/exec/obidos/A...J7DS/blyong-20

CPAP and fan are 120V. Freezer plugged into 12v. Fridge on propane. water heater off. Cell phones charging. that's it...like I said, I have a hard time believing that this is draining our batteries overnight. I was sure that 4 6 volt would cover our usage.

thanks,
Pam

[N6ZCM1]

Pam..

I am sure then the Freezer is cycling thru the night so it is not pulling 4.5 amps all night! which is good!!
As for the Cpap... since you are using it on the AC side 5 amps at 120 volts is 600 watts then divided by 12.5 volts comes out to 48 amps of DC current, along with the fan maybe at 1 amp 120 watts, which would be 9.6 amps at 12.5 volts.
Now your Cpap 5 amps is more than likely start amps, then running amps is a little lower. If you inverter display shows AC amps, what is that reading?
Then I could see a 40 to 70% drain on the batteries!
And taken into account that you are watching T.V. at night or some lights before bed would account for your usage too!

When ever deciding on a AC product to run off of a Inverter from 12 volts... look at the Watts then divide by 12.5 volts.. or a simple way take the amps add a zero to the end... so 10 amps AC becomes 100 amps on the DC side.

[paphil]

Thanks. I'll check the amps from the cpap tonight.

[Wizbangdoodle]

We were setup about the same (just upgraded from 4 6v AGM to 8). Which had us at 448ah. Running 1 CPAP and a fan, we were using about 18 amps out of the batteries. We left everything else in idle mode, ie satellite equipment etc. I have all Magnum equipment and use their battery monitor kit that allows me to see exactly what is going into or out of my batteries at any time. With 4 6v and at 100% charge, we would only drop to maybe 80% charge. I suggest getting something that can tell you exactly how many amps are coming out of your batteries. Also, were the batteries brand new? If not, they could have had a problem when you got them.

Sent from a trailer.

[Jims94vmx]

Just something to watch for in the next few years, The RV Dr was at the Hershey show and did a seminar on Solar. He mentioned that LiOn batteries would become more readily available. These would be way less weight and a lot more power for longer. Does not help now, but thought i would throw it out there......maybe you guys already knew this....

[Najataagihe]

Hints:

Most CPAP units have a 12-volt input. If yours does, use it. You may have to go buy an adapter plug that will fit your unit and splice it into a 12V accessory plug, but it draws a LOT less juice, this way. Just run it directly off a 12V source. I use this one:

https://www.amazon.com/100-Watt-Port.../dp/B01M3S00H0

It not only provides 12V, it acts as an uninterruptible power supply for the CPAP - nice insurance against the generator shutting off.


Turn off the humidifier's heating element and just let the air flow over the water. A lot of times, this is sufficient to keep from drying out your sinuses. This is the major source of current draw.


Get a 12-volt camping fan. They use a lot less energy than using a 120V one that requires an inverter.


General rule: anything you can run off 12V, do it.

There is a lot of juice lost to conversion when you go from 12V to 120V to whatever step-down transformer is in your equipment.

Have fun!

8)

[paphil]

Update...we have moved into cooler temps. Dry camping now with freezer, cpap machine and furnace set at 60 degrees. Batteries have been discharged down to 60 percent each night. Not running fan has made a world of difference. We will not use our fan when dry camping from now on and that will eliminate the need to add more batteries. Happy camper now

[Cate&Rob]

Not running fan has made a world of difference. We will not use our fan when dry camping from now on and that will eliminate the need to add more batteries.

There are some great 12V fans that will move a lot of air for very little current draw. We have tried several different kinds on our (non-AC) boat and these are by far the best. http://www.caframolifestylesolutions...arine/sirocco/ Less than 1/2 amp on high but we seldom run on more than low. You can run one all night long on low for less than 2 Ah.

Rob

[tedzz9]

A Bourbon dispenser draws next to no amps!!!!

[paphil]

You think my husband doesn't already know that !!!