solar power for dry camping & cpap machine
***Link Removed******Link Removed***Hello, I recently purchased a 2006 Thor Wanderer 30' travel trailer. I was disappointed that I could only run my cpap machine when the trailer is plugged in. I al...
Forum Discussion
Hi,
You spoke of bottlenecks. In this case the battery becomes the bottleneck. A 12 volt jar is tested at 25 amps demand. You can draw more but at some point voltage starts to sag badly. 75 amps is about the limit for a 100 amp-hour jar.
A 3000 watt inverter, running flat out, may draw 300 amps. So to "feed" it may be best to use 4 100 amp-hour 12 volt batteries wired in a balanced manner.
You also mentioned a stand alone battery for the inverter and another one for the house loads. That is a poor way to implement powering the cpap. It would be far better to put the batteries in parallel.
There is often, no reason to not run an inverter when plugged into shore power. I used to do this often with a 2500 watt MSW inverter to allow me to run extra devices beyond what the shore power could provide for.
However, I am unable to do that with my Magnum 3000 watt inverter as it blows the reverse polarity fuses on my converter due to a high inrush.
You spoke of bottlenecks. In this case the battery becomes the bottleneck. A 12 volt jar is tested at 25 amps demand. You can draw more but at some point voltage starts to sag badly. 75 amps is about the limit for a 100 amp-hour jar.
A 3000 watt inverter, running flat out, may draw 300 amps. So to "feed" it may be best to use 4 100 amp-hour 12 volt batteries wired in a balanced manner.
You also mentioned a stand alone battery for the inverter and another one for the house loads. That is a poor way to implement powering the cpap. It would be far better to put the batteries in parallel.
There is often, no reason to not run an inverter when plugged into shore power. I used to do this often with a 2500 watt MSW inverter to allow me to run extra devices beyond what the shore power could provide for.
However, I am unable to do that with my Magnum 3000 watt inverter as it blows the reverse polarity fuses on my converter due to a high inrush.
TxGregory wrote:
12gen,
I am with you. I would like to go with a smaller inverter, then I could stow it in its own battery box with the controller. But If I did that, I would have to be really careful about what I plugged into my abundance of AC outlets in my trailer. And for that matter if someone turned on the Air conditioner, it would trip the inverter. Oh, and there is the microwave.
Whereas, if I go with something that will put out close to 30 Amp, 120 volt, then I would not have to be so careful. (my controller supports 4X100W panels). I plan to add a couple of more batteries and panels in the future. So I am thinking that making everything capable of supporting 30 Amp 12 Volt will be a better solution long term. I used to design and build IT, and we always had to be careful about bottlenecks. I don't want my inverter to be a bottleneck. Now my assumption has been that if I had the 3000W inverter plugged into a 12v 100amp/hour deep cycle rv battery ... and I ran the Air Conditioner, that it would drain the battery and do no harm. I saw a post from someone with a configuration similar to mine and that is what they said their did. If I am wrong, I would sure like to find out before hand! :)
