lawrosa wrote:
It would be more efficient if you got the 12v adapter and plug it directly to 12 volts. But those cords are expensive.
$119 bucks for mine.. And I would have to install a 12 volt outlet near the bed.
This is exactly what I did. I installed a 12v outlet/USB port by my bed. (See my thread What was Airstream thinking (part 2)?.
My 12v power cord was $35.00 delivered.
My c pap used 50 watts with humidifier and heated tube.
Running it through an inverters equates to 4.2 amps or so. Plus at least 10-15% losses through inverter you may be looking at 6 amps.
Thats about 50 amps for a 8 hour sleep.
And what else may be running in the camper?
If you had two 12 volt 75ah batts thats 150 ah. But usable is 50%. Thats 75ah. You would have to make sure batts are 100% charged because by morning you will be close to 50% discharge..
Now the issue is to get those batts 100% for the next night... Not going to happen. You may get batts to 90% if you have good charging capabilities.
With all this said, youll be a head of the game if as stated you do not use the humidifier and heated tube.
My unit runs a mere <5 watts with no humidifier or tubing on. That's about .4 amps. With inverter losses not even 1 amp.
So now in 8 hours you will not even use 8 amps from the battery...
It would be more efficient if you got the 12v adapter and plug it directly to 12 volts. But those cords are expensive.
$119 bucks for mine.. And I would have to install a 12 volt outlet near the bed.
Just a note.. My inverter is a 1000 w model and run with 2 gauge wire.
a 400 watt inverter can draw 35 amps or so.
You need to use #6 wire for up to 10ft away from batteries.#4 is 15 feet, #2 if 20 ft. That will give you a 3% voltage drop across the wire
Running it through an inverters equates to 4.2 amps or so. Plus at least 10-15% losses through inverter you may be looking at 6 amps.
Thats about 50 amps for a 8 hour sleep.
And what else may be running in the camper?
If you had two 12 volt 75ah batts thats 150 ah. But usable is 50%. Thats 75ah. You would have to make sure batts are 100% charged because by morning you will be close to 50% discharge..
Now the issue is to get those batts 100% for the next night... Not going to happen. You may get batts to 90% if you have good charging capabilities.
With all this said, youll be a head of the game if as stated you do not use the humidifier and heated tube.
My unit runs a mere <5 watts with no humidifier or tubing on. That's about .4 amps. With inverter losses not even 1 amp.
So now in 8 hours you will not even use 8 amps from the battery...
It would be more efficient if you got the 12v adapter and plug it directly to 12 volts. But those cords are expensive.
$119 bucks for mine.. And I would have to install a 12 volt outlet near the bed.
Just a note.. My inverter is a 1000 w model and run with 2 gauge wire.
a 400 watt inverter can draw 35 amps or so.
You need to use #6 wire for up to 10ft away from batteries.#4 is 15 feet, #2 if 20 ft. That will give you a 3% voltage drop across the wire
