Portable Solar pannels - for emergency ? Your choice ?

[MarcLeQuebecois]

Good day all,
I am building my stand alone nav system, ie something I can take from one boat to the other... or as back up / emergency system if and when I finally buy a boat OPEN CPN on a small PC, Navionics on tablet, hand held Garmin GPS... Anyway, the question is.. I want to have a small portable solar pannel to power those things in case everything else fails.. (had that once.. big power issues...)

Sounds fairly easy for Ipad, smartphone, rechargeable batteries for small GPS.. But when it comes to the small PC.. more complicated.. but anyway, that would be extra..
Any good experience with portable solar pannels ? Features ? Size recommeded ?

Looking at 21 watts, 28 watts, 40.. size matters a bit too.. additional luggage..

Falcon 21 or Falcon 40 says will charge small PC up to 40 watts .. my sector charger for the PC says 45 watts.. will it not charge at all ? It has a DC output ...
And another one also has a DC output of 18 volts.. but again my PC charger says 19.5 volts, again will it not charge at all ?

many thx for any feedback or product recommendation. Cheers safe sailing. Marc

[ohgary]

As with most solar projects, You dont start at the panel, You start at the load. How much power do you need to charge your battery? Look at most "mobile laptop chargers for laptops and they are 65-100watts units. Now keep in mind thats to not only charge but power a laptop with it running full speed.

Also dont overlook the needs of your IPAD, Those things can be power hogs if you have bluetooth, wifi or cellular on. Keep in mind they take 3 amps at 5v, Thats 15 watts. Cell phones will vary, but 5watts is a good start.

Once you decide on your load you should look at storage. Are you going to power the devices directly or going to power a battery that will then be used for charging.

I would stay away from anything that needs 120v since there your going to need an inverted and again more losses in conversions.


Once you get your load then figure out your panel needs.

[Pizzazz]

If you are trying to build a portable navigation system, you can’t do better than just having an Android phone with a larger, say 5” display. Use Navionics for charting, SailGrib for weather download and routing and you are all set and your power requirement would be tiny. If you want more integration, on newer boats you can just connect to the WiFi enabled displays, on older boats I would consider a Seatalk or nmea to WiFi adaptor than you can plug into any Seatalk port on the guest boat. Then get a cell phone charging panel, a mount and be done with this.

[MarcLeQuebecois]

Thx for that,
My lap top pulls 45 watts, but I would just charge it when its off... but again that would be a bonus... I might just stick with Ipad, smartphone and batteries AA for portable GPS ... So one Samsung tablet, 6000mAmp battery I believe, USB charger for AA batteries, Smartphone.. that's it. And I would use a back up external power pack, say 20,000 mAmp, charge it with the solar pannel, then charge the the devices.. apparently not good to plug a smartphone or tablet strait on the solar panel, many don't have a regulator so can damage the battery of the end device. And again this is for emergency in case no other charging option on board anymore, so would not be for constant use... So I figure 21 watts pannel might do it ? 40 watts is almost double the weight, 1 kilo instead of 500 g... cheers

Originally Posted by ohgary

As with most solar projects, You dont start at the panel, You start at the load. How much power do you need to charge your battery? Look at most "mobile laptop chargers for laptops and they are 65-100watts units. Now keep in mind thats to not only charge but power a laptop with it running full speed.

Also dont overlook the needs of your IPAD, Those things can be power hogs if you have bluetooth, wifi or cellular on. Keep in mind they take 3 amps at 5v, Thats 15 watts. Cell phones will vary, but 5watts is a good start.

Once you decide on your load you should look at storage. Are you going to power the devices directly or going to power a battery that will then be used for charging.

I would stay away from anything that needs 120v since there your going to need an inverted and again more losses in conversions.


Once you get your load then figure out your panel needs.

[tkeithlu]

Are you using panel wattage "ratings" or your experience with output? The sun is not always at 90 degrees overhead, and it kind of poops out at night.

[john61ct]

Get all your load devices working together first, put the PV power system together last.

You will need to measure the Ah consumed per 24-hours by the rig as a whole

and then factor in weather, longitude insolation factors, as well as how long you want to operate in cloudy winter weather

before trying to size panel wattage and battery storage capacity.

As in, actually measure current drawn over time during representative use patterns.