Will this solar charger work with my machine?

[SleepPlease]

I'm using a Philips Respironics BiPAP autoSV Advanced System One and will be traveling soon to a powerless area. Can any of you electronics wonks out there tell me if the following Goal Zero solar charger will work with my machine?

http://www.rei.com/product/866043/goal- ... olar-panel

[CapnLoki]

I'm using a Philips Respironics BiPAP autoSV Advanced System One and will be traveling soon to a powerless area. Can any of you electronics wonks out there tell me if the following Goal Zero solar charger will work with my machine?

http://www.rei.com/product/866043/goal- ... olar-panel

No. First of all, we need to know the location and season to guess at the solar power that might be available. And second, since you probably are not powering the pump directly from solar we need to know what type of battery, since they have varying requirements and capabilities.

If we assume a PRS1 560 Auto, running at pressure 10 with no humidity, you will need about 0.7 Amps, or about 6 Amp-hours per night. This is about 75 Watt-hours. Your autoSV pump, however, could take a lot more power, especially at higher settings, so you could need as much as 200 Watt-hours. If you do need this much, there's no way to power it with panels and batteries you can carry easily.

The way to estimate the expected power from a solar panel is to find the Average Sun Hours for your location, and then assume full output for that time. For much of northern US (like New England) that number is 4 in the summer, in Arizona it can be as high as 7. You can do a bit better if you continuously aim the panel or if its very sunny, and a lot worse if its shaded or cloudy. Since the output of this panel is 7 Watts, you might assume you would get 28 Watt-hours, which won't come close to covering one night. Actually this panel uses a regulator/converter to produce 15 Volts for charging a 12V battery, and that only produces 5 Watts max, so you might not see more than 20 Watt-hours. This is really intended for cell phones and iPods; even a tablet would be marginal.

To generate enough power most really need around 30-50 Watts of solar panels. That would, on a good day, provide 100-200 Watt-hours. Since your requirements are higher you might want 100 Watts of panels, certainly more than you can "carry in." You also need a battery that can cover at least several nights, and be big enough to recharge that power in 8 hours. This would allow you to handle one or two overcast days and then recharge when the sun comes out.

BTW, I have 150 Watts of solar panels on my boat - I assume on a sunny day I might get 50 Amps-hours, or 600 Watt-hours. Ideally, this would be enough to cover all my needs (fridge, tv, radio, computers, cpap...) but one cloudy day and I have to fire up the generator!

[SleepPlease]

Thanks, CapnLoki. I can't provide power details at the moment because the machine is at home, but I think you've pretty much answered my question. I'd rather not run the generator all night, but batteries like the C-100 are a bit too pricey for camping 2 nights annually.

[SleepPlease]

Without knowing my power specifics and taking an educated guess, is there a battery you would recommend at least looking at? Considering I'll only be camping ~2 nights per year?

[CapnLoki]

If you're car camping, you can use a deep cycle battery. A $80 Walmart is rated at over 100 Amp-hours, which should cover your machine for two nights without humidity. Even if you exceed the recommended 50% level for this battery, since you only need it once a year it really doesn't matter much if its slightly damaged.

Of course if you're carrying in 20 miles, you don't want to lug a 60 pound battery, or a small generator either!

[SleepPlease]

It's car camping, so I'm good with the deep cycle battery. What gear (converters, etc.) will I need to actually plug my machine in?

[Guest]

I don't know anything about rei but I can say I would not buy anything from someone I have to pay money to give them my money that includes the warehouse clubs.

[Goofproof]

I don't know anything about rei but I can say I would not buy anything from someone I have to pay money to give them my money that includes the warehouse clubs.

I take that to mean buying from the U.S. Government too! Jim

They even manufacture the money, out of very thin air.

[Guest]

I don't know anything about rei but I can say I would not buy anything from someone I have to pay money to give them my money that includes the warehouse clubs.

I take that to mean buying from the U .S . Government too! Jim

They even manufacture the money, out of very thin air.

fwiw - I do not buy from the govt either.

[MINItron]

I don't know anything about rei but I can say I would not buy anything from someone I have to pay money to give them my money that includes the warehouse clubs.

REI is a CO-OP. Anyone can become a member of REI at that point you are an owner of the company, and you can receive dividends annually based on your purchases. You do not have to be a member, and there is generally no discount for being a member. Anyone can buy from REI at anytime.

[CapnLoki]

It's car camping, so I'm good with the deep cycle battery. What gear (converters, etc.) will I need to actually plug my machine in?

First you have to figure your needs. Find your machine on cpap.com and follow the Power tab. This should tell you you can use direct dc power, or need an inverter. There's usually a menu selection for matching batteries that will help figure the power needs. Track that down, I can help interpret the numbers.

My hunch is that 100 Amp-hours is enough. A Walmart or other basic deep-cycle will start at $100 or less. These are flooded, so you have to worry about spilling acid and adding water, etc. For $200 to 250 you can get an AGM battery that can run upside down. I like the Battery Tender that will gently charge and keep the battery ready.

Do this research and we can get closer to a solution.