PowerSwitch

Just a quick question. Is it possible to directly charge the battery of a laptop computer via a solar panel, or even a dynamo rigged up to an excercise bike? If not what'd you need to make it so & what size of solar panel would be needed?

AllanH

AllanH wrote:Just a quick question. Is it possible to directly charge the battery of a laptop computer via a solar panel, or even a dynamo rigged up to an excercise bike? If not what'd you need to make it so & what size of solar panel would be needed?

AllanH

Certainly - I think there are commercial solar products available, check Google or maybe even ebay.

clv101 wrote:Certainly - I think there are commercial solar products available, check Google or maybe even ebay.

Why -- it's fairly easy to knock-up a charge controller/regulator for about 6 to 10 quid in stripboard. Then you just plug it straight into the power plug of the laptop (if you're desperate, in best Blue Peter mode, "I've got a circuit in my attic which I made earlier" for last year's big Green Gathering).


P.

Of course the problem with this is that laptop batteries are notoriously short lived. If you get 2 years out of a laptop battery without it reducing to a 15 minute life you are doing well!

If this is really important to you then I suggest you purchase 3 or 4 spare batteries for long term use.

Lithuim ION batteries in the current laptops are fairly good. I would in general expect them to last around 3years. In my experience at work 3 years hard use is about right, by that time we are upgrading the laptop also, so they may last longer. We get the odd failures, but in general 95% last well. Things to remember, do not run them completely flat and remove it from the laptop when not being used for long periods. Keeping a spare is an excellent idea, I have a couple.... but you want to charge them every few months.

A friend of mine who is often messing around with electronics says that when a Li-ion laptop battery packs up, it's usually just one cell that's gone, and if you have more than one battery you can take them apart and assemble one that will keep working a bit longer. Never tried it though.

I've tried charging a laptop from my little (18W) solar+battery setup. I have a car power socket wired into the charge controller, and then you can plug in laptop adaptors intended for use in cars. The adaptors support a range of voltages, and come with a variety of connectors - I've been using mine to power an AA battery NiMH charger as well.