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1. How do I power my laptop using solar power?

Laptop computers consume between 15 and 30 watts of power (some as much as 60 watts). Much less power is required when in standby mode. Most of this rated power is consumed during startup (bootup) and much less is used during usual operating conditions. The ConnecticutSolar Backpack 20 watt or 32 watt solar modules are ideal for solar power of your laptop. Generally either one 32W and in some cases two are required.

Some laptops work with only 32W of panel capacity. To decide, multiple the output voltage labeled on your laptop's wall adaptor  (usually a black plastic box in-line with wall plug) by the current (in amps) and this will be the number of watts your laptop uses during startup.  Most laptops use input voltages between 16 and 22 volts at usually 2 to 4 amps (doing the math above, this is between 32 and 88 watts). You will need something around half that size to 60% of that size size in solar panels to power your laptop (sometimes a bit less as this is often the peak power consumption; with conservative power settings you will often draw less). in our considerable experience operating laptops from sunlight, you will usually get away with one panel but often wish you had two (if you use the laptop continuously for example). If you're going on a serious expedition we suggest the Standard system (two 32W panels). If weight is an issue, one perhaps. You can acquire the basic system and test it. If you decide to add a second panel you can do so later.

You will need an automobile power adaptor for your laptop  (one that has a automobile cigarette lighter receptacle male connector on one end). The solar module will have a cigarette lighter receptacle into which you will plug the converter. The laptop will view the solar panel as a battery and will charge and/or spare the battery when in full sun.

Some adaptors are intolerant of the solar panel voltage (17 to 20VDC full sun no load).  If this is the case you will need either aDC-DC adaptor or alternatively a  Power Center  which includes a 16AH battery and charge controller (available assembled from ConnecticutSolar with connectors). The PowerCenter moderates the solar panel voltage and provides the proper voltage for the adaptor. During startup the power center also provides the 8A or so most laptops expect during bootup (that would require over 120W of panel capacity).

If you desire to power your laptop and other consumer devices, we recommend a 16AH power center. Weight is around 10 pounds but you will be able to power  your laptop and other devices as desired. Specify two sockets for the output (one for the laptop the other for other devices). Use a 20.8W, 32W or two of either to charge the power center. The size of the panels you use determines how long you will need to charge the power center prior to running the laptop (the lower the panel size, the less time you will have to run/charge the laptop prior to re-charging the power center. Usually two 32W panels will allow you to run the laptop indefinitely in full sun.

2. Are there any special settings I will need on my laptop?

Yes, we recommend that you set up the most conservative power settings. These will often be found on Windows machines in your settings directory. Other machines may have the setup in the BIOS settings on bootup. Set the computer to go into suspend mode if not used for a given timeframe and set the most conservative "e;powermiser"e; settings if available. This will limit the  quantity of power needed. Charging the laptop internal battery while powered-down is also useful (prevents having to supply the internal devices and monitor, allowing the panel to focus primarily on charging the battery).

3. What should I monitor during use?

Most laptops have a battery charge monitor. Keep track of this and shut down to recharge when the battery is depleted beyond (usually) 25 percent charge or so. Laptop batteries will charge much faster with the computer itself shut down.

4. What should  I do to most quickly recharge my laptop?

Depending upon your laptop you can charge in full sun with the laptop running or for quicker charging with the laptop shut down or suspended. Keep the panels facing the sun and tilted at an angle equal to your latitude plus 10 degrees (i.e. at 40 degrees latitude set panels at 50 degrees from the horizontal). A little less during the summer.

5.What if I can't find the correct connector for my laptop?

Inquire, we can usually find the correct adaptor for your. If not, One option is to use a 110V inverter to allow you to charge with your 110 VAC wall adaptor. There is some loss of efficiency but in full sun you can run the laptop virtually unheeded. We can wire the Power Center with the inverter option. This option also allows operation of any other low power 110 VAC device.

6.Are there differences between laptop solar panels?

Yes, big differences. Look carefully at solar panels
being sold for laptop power use. Many are relatively
poorly constructed or under-powered (you will usually
need at least 40 watts of panel capacity). Most won't work well with a laptop because of voltage incompatibility. Often you will need an external battery/charge controller. We do a lot of work fixing people up with laptop power who purchased units that did not work. Think about it: how will your 40 to 60 watt laptop charge with a 10 to 15 watt solar panel? Plus you pay way too much on a per-watt basis for these marginal panels that usually won't work with your laptop. Our panels have been on every continent on Earth in the most demanding conditions. Caveat emptor.

7. Can I run my laptop longer using the power center?

Yes, The power center strores 16AH of energy. This means you can draw 1 amp for 16 hours continuously or 16 amps for 1 hour. Most laptops (once started up) draw about 3 to 4 amps at 12VDC so you can power the laptop an additional 4 to 5 hours after the sun sets (on average).

8.What kinds of connectors are on your units?

The panels have female cigarette sockets and the power center has two plugs that connect to the panels via these connectors. Loads (laptop and other loads) are connected via two female sockets that exit the power center.

9.What kind of controller is used in the power center?

We embed a ProStar controller that has an LCD display of pack voltage, current coming from your panels and current to your loads. This sophisticated controller has three charge modes and uses pulse width modulation to charge batteries accurately. The unit is temperature compensated (float voltages are lower in hot temps and higher in the cold). The controller also protects the battery pack against over current and over-discharge.

10.What accessories do you recommend that I purchase with my power center?

We recommend the power center charging system. All batteries will self-discharge when not in use. The power center needs to be kept charged to prevent over-discharge of the batteries. The best way to do so is to purchase the custom charging system designed for 110VAC. You just plug your power center into the wall socket and it remains fully charged and ready to go. The embedded charge controller keeps the batteries in full health and keeps the system healthy..
11.What are the advantages and options for the Tekkeon Systems?

The Tekkeon Systems are available with two configurations: the 3450 unit and the 3700 unit. The 3450 has a user-selectable voltage output for running things that have a specific voltage required. The range is from 5VDC to 19VDC. Ideal for portable 13.2VDC devices like radios, transceivers, gps units or anything that plugs into a car socket. The 3700 unit has an automatic voltage determination protocol designed for laptops and automatically determines your laptop voltage and selects it. The 3700 unit is used mainly for a laptop. The 3450 for other applications.

The main advantage of the Tekkeon units is that they contain lithium batteries and are therefor lighter weight. They also are very compact. These units both come with a variety of adaptor plugs to fit most all laptops and most consumer devices. They also have a USB output for charging USB devices that normally charge from your PC.

The main disadvantage of the Tekkeon units is that they are available in only 5 and 10AH configurations. The larger lead acid power centers we cell may be heavier but they can be built and are available in a number of much larger capacity sizes. Additionally, our conventional power centers have LCD displays of voltage, current in and current out. Also the Lead acid units (8AH, 16AH, 24AH, etc.) are all weatherproof and more ruggedized. The Tekkeons also only can accept one 32W panel input whereas the Lead Acid units can accept much larger panel capacity inputs up to 16A continuous. If you are going on a serious expedition the Lead Acid units are much more durable and flexible. If you're backpacking and weight is the major issue, then the 10AH Tekkeon with a 32W panels is best. We are glad to explain further as needed.