Camping

How can I charge my marine battery while car/ F 150 camping? And there is no power outlets around.
Thanks

SleepingMailman wrote:How can I charge my marine battery while car/ F 150 camping? And there is no power outlets around.
Thanks

Two choices are solar or charge it right off the car/truck letting it idle for 10-30 min depending on how much charge it needs. I think I'd hook it up so you could charge it while driving also.

Guest wrote:

SleepingMailman wrote:How can I charge my marine battery while car/ F 150 camping? And there is no power outlets around.
Thanks

Two choices are solar or charge it right off the car/truck letting it idle for 10-30 min depending on how much charge it needs. I think I'd hook it up so you could charge it while driving also.

Yes, you can use an inverter to charge a battery while driving.

SleepingMailman wrote:How can I charge my marine battery while car/ F 150 camping? And there is no power outlets around.
Thanks

How many nights are you camping? An automotive sized battery will hold maybe 600-800 Watts when fully charged. With no heated humidifier I would be able to run for at least a week easily off that battery on one charge, probably more like 10+ days. My PRS1 uses maybe 7 watts at 14cm pressure and no heated humidifier.

RogerSC wrote:

Guest wrote:

SleepingMailman wrote:How can I charge my marine battery while car/ F 150 camping? And there is no power outlets around.
Thanks

Two choices are solar or charge it right off the car/truck letting it idle for 10-30 min depending on how much charge it needs. I think I'd hook it up so you could charge it while driving also.

Yes, you can use an inverter to charge a battery while driving.

you wanna rethink that statement?

Generator or solar to recharge or swap batteries and drive you truck around. It really depends how many nights you're going to be camping though. I've slept 3, 7 hours nights with humidifier and could have gone another couple if I needed. If your run your machine without the humidifier, you could probably get 7-10+ days without recharge.

SleepingMailman wrote:How can I charge my marine battery while car/ F 150 camping? And there is no power outlets around.
Thanks

Short Answer:
Just connect the battery to the truck system - jumpers will do but be careful - and run the engine. The low idle might not be enough to "turn on" the alternator, so you might want to rev the engine slightly so it gets up to 1500 RPM. About 15 to 30 minutes would normally recover a night's usage.

Long answer:
First, how much power do you have? A car sized marine deep cycle battery will have about 100 Amp Hours. The guideline is the more than 50% discharge wears down the battery, 80% is serious wear, so you might have around 50 Amps-hours to use. Next, how much do you use? A simple pump with moderate pressure might use 3 Amp-hours a night, but if you're in the desert and need full humidity, it could go as high as 40 Amp-hours. Also if you use an inverter rather than a DC power connecter you'll need more power. This means your battery could run for anywhere from 1 night to 2 weeks before needing a charge. To help estimate refer to:
http://www.resmed.com/assets/documents/ ... lo_eng.pdf

If the draw is low (no humidifier) you shouldn't bother recharging until the battery is down at least 30%. This is because the battery will only accept a small current if its only down a bit. The protocol for cruising boats and RV's is to start charging when down 50% and stop when it gets up to 85%. (Periodically a full charge is needed to keep the battery healthy.)

Tips:
Make sure the battery is "deep cycle" - a starter battery won't last long.
If you have a PRS1 pump get the 12V connector. If its a S9, get the 12-24 DC converter. If you must use an inverter, carry a spare (it will be the weak link) and assume 50% efficiency.
If the truck has a voltmeter, or you have a VOM, measure the voltage while charging. You want 14.2 to 14.4 Volts; under 13.8 won't do the job and over 14.6 is over charging. If the battery is well discharged, it might take a while for the voltage to build up.
A 100 Amp-hour battery will accept about 20 to 25 Amps if 50% discharged, and your truck alternator should easily put that out. Thus, the 50%-85% protocol I mentioned would mean about 75 minutes of charging, but that might be 10 nights use.

Do a search of this entire forum for words like "camping," "battery," "battery power," etc. and you will find a bunch of great information here last spring. One of our forum members did a great job of researching and trying various methods of CPAP under field conditions. Also, very good information for disaster breathing, too.

Don D

Camping is one of the reasons I elected to have surgery to get off the cpap permanently.