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Solar panel for running a notebook?

By cgreen7 ·
I am trying to connect a solar panel to charge the battery of my Compaq nx5000. (The solar panel is a Brunton SolarRoll 14, designed to recharge notebook computers in the field).

The problem -- the connection cord from the solar panel to the computer's power-input jack has 4 possible connectors, none of which fit the input jack on the Compaq nx5000. The power cord supplied with the Compaq nx5000 has an input connector with a yellow plastic end and a circular hole with little square cutouts on two sides of the hole. So I presume that what I need is some sort of adapter with a similar-shaped connection on one end, that will fit into one of the 4 possible connectors from my solar panel.

Does anyone have any experience with such an issue? Has anyone successfully used adapters to connect differently-designed equipment? Any ideas of where to look for such adapters or what they are specifically called?

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A bit of electrical splicing will do

by Why Me Worry? In reply to Solar panel for running a ...

but make sure thw solar panel is providing the right amount of amperage and voltage so that you don't fry your laptop

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by FluxIt In reply to Solar panel for running a ...

directly connect to the load. Usually they go through some circuitry to condition the signal (grounding capacitors to prevent overvoltage and inductors to smooth the current) and then charge a battery. The load is then drawn from the battery.

There are plenty of books having the circuits in them and websites providing the components.

Try looking here:

Also try for parts. Do not use radio shack stuff. It is the lowest grade quality components. You may wirewrap a good circuit board but if the parts are junk you'll be frustrated...

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You will need a lot of sun!

by jmgarvin In reply to RARELY DO SOLAR PANELS...

Your laptop needs a lot of juice. While the solar panel may help your battery recharge, it isn't going to help you get much more out of your battery life. Also the mounting is a PITA as you either have to place them on the top of the screen (when it is open ) or the back of the screen.

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Well firstly the specs of the Solar Cell

by HAL 9000 Moderator In reply to Solar panel for running a ...

Say recharge not run and if you look at the specs of both items I very much doubt that the Solar Cell will provide enough voltage to actually charge the battery.

The Solar Cell produces 15.1 Volts DC MAX and the Compaq Battery is 14.4 VDC Battery so under ideal conditions without any protection circuitry the ability to charge the LT's battery would be marginal and that is only with the standard battery not the large capacity one that is optional. The estimated recharge time from the mains is a little over 3 hours so with this Solar Cell you can at the very least triple that time again under ideal conditions as the Solar Cell doesn't provide anywhere near the same amperage as the mains charger.

While it is one of the new generation Solar Cells these are not all that efficient and are at best only about 8% efficient compared to the older generation ridged cells which have a 22% efficiency rating. So you'll need a much bigger area for the same power supplied from a conventional Solar Cell. Not to mention the price difference between the two.

Now as far as protection circutirty is concerned the above posting gives you the right idea but you also need a cut out so you will need to build some form of monitoring system into the circuit to cut off the Solar Cells power when the LT's battery is fully charged so as not to damage it you can not rely on the built in protection as it is aimed for a much larger amperage and voltage so in all probability it will not cut off the power when the battery is fully charged and cook the battery slowly. The resulting fumes that are let off by the Battery could well destroy the LT all together as they are very acidic and consequently quite harmful to the LT's internal components.

Personally I would buy a few spare batteries and then if you are going to be away from mains power for long periods you'll need a higher Voltage Solar Cell and some very sophisticated protection circuitry that can charge the battery out of the LT and cut off when it becomes fully charged. I would recommend a 20 VDC Solar Cell for this and as high an amperage as you can get then you can build the protection and cut off circuit and connect it directly to the LT'S battery when it is out of the LT.

I would also only consider using the ridged Cells as they are far more robust and less susceptible to damage than the flexible ones are. Sure it is nice to be able to roll it up and pack it away but if you roll it too tightly or drop something onto the Solar Cell you can destroy it where as with the ridged ones you can drive a car over them without doing any damage.

I've used this type of thing in 3 rd World Countries where there is no reliable power supply and they are quite effective even though the roof of a car is used to mount the Solar Cells on and the batteries are charged inside the car while you are away and the car has to be left in the sun so no parking it under cover or the efficiency drops as low as 2% on a sunny day and nothing when there is no direct sun light.

It would work out much cheaper to buy a small petrol generator to recharge the LT and with what you save on the generator you could buy several spare batteries as currently here I can pick up a 750 VA generator for $199.00 AU compared to the $300.00 US price tag for the Solar Cell.

The generators are small enough to fit into the boot of a car and have the added advantage of not requiring any other modifications to recharge the LT as all of the recharging circuitry is already built in or provided by Compaq. With one of these it would even be possible to not only run the LT but be recharging it at the same time so you wouldn't have the massive time delays involved in recharging the battery.

Just something to think about.

Col ]:)

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Just another thought here

by HAL 9000 Moderator In reply to Solar panel for running a ...

How about using the current Solar Cell to charge a Lead Acid 12 Volt battery and then use an inverter to produce mains power. You could use one of the sealed jell type batteries to so you wouldn't have any worries about it spilling its contents over things and destroying them. You should be able to pickup the battery from the same place you got the Solar Cell and the inverter should be available from Radio Shack.

That would be the easy answer as you already have the charging ability and no modifications would be required.


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