Solar power laptop

[stoo]

This plan involves the solar cells being part of the laptop, not some optional extra PSU. The plan is:

1) Rebuild battery for my PowerBook Duo with 2100mAh cells instead of the original (dead) 1600mAh ones for 6 to 8 hours of battery life.

2)Acquire solar cells, attach in some fashion to top of laptop and external PSU connector on the back of the laptop.

3)Roam far and wide with truly portable laptop, free from the grid.

Any ideas for the solar cells? It needs about ~7W maximum power and is about 250mmx300mm.

[Adisharr]

Can you supply some details on your voltage and current requirements?

You'll also need some kind of regulator to stabilize the output most likely. Check out the below link for one mfg.. Prices seem reasonable. I thought they would be more expensive than that.

http://www.siliconsolar.com/

[stoo]

Ooops, forgot.

It draws 500mA at 14V when booting. When in use, it can draw up to 740mA or a minimum of 170mA at around 14V. For continued operation it'll need around 14*0.4 = 5.6W.

The battery is composed of ten 4/5AF cells, rated at 1600mAH. The replacements I'm currently looking at are rated at 2100mAH.

I've built regulators before, but that was for a desktop machine. I'll have to be more space efficient but I think there's enough (the internal modem slot is free and unlikely to be used).

I'm doing this on an old laptop first in case I mess it up

Silicon Solar prices look quite reasonable, even after shipping and customs add to it.

[Adisharr]

That's gonna be a cool mod.. Make sure to keep us updated

[zackbass]

Squeezing some control circuitry into it shouldn't be too hard, there's a lot more space in a laptop than you'd think.

[stoo]

I'll find out how much space I have when I get it properly apart. It needs some new bolts because the old ones are a bit chewed.

First I've got to get a multimeter for rebuilding the Dock PSU and the battery: quick trip to the store on Saturday.

[Mr. Bombastic]

There are already some products here under the 'alternative energy' category.

Maybe you could get wireless internet too and have a totally stand alone laptop!

[stoo]

There's a Maplin not far from me: that's where I intend to get my more regular "supplies".

Wireless is unlikely, as this machine has no expansion slots (except modem and RAM, both proprietary). However, the intention is that the solar power stuff will be transferable to more modern laptops.

Maplin's 4/5AF Nickel Metal hydride cells are 1500mAH. The ones I've spotted in the US are 2100mAH and about the same price, even after VAT, shipping, import duty, etc...

This project may take a while, so don't get too excited . I'll try to have some progress before it disappears of the end of Completely Custom. Ironically, I'll probably finish it when it will be the least use (winter) :rolleyes:

[stoo]

Update (minor): I've successfully repaired the Duo Dock's PSU, as per the instructions around the web.

The Dock is the Duo's base station and contains a floppy drive, a 68882 FPU (the 68030 uses a coprocessor FPU, a bit like the 387), some more VRAM, another hard drive (300MB SCSI! w00t! ) and two Nubus expansion slots, so it now has a ethernet card. The only ports on the back of the laptop are power, serial and the Dock connector.

Steps involved:[list=1][*]Buy 25V, 100uF capacitor for five pence from Maplin[*]Dismantle Duo Dock and remove PSU[*]Drill rivets out of PSU[*]Hunt for capacitor C28 for ten minutes, find it under the piggy back power out connector[*]Replace C28, involving soldering in a tight space.[*]Reassemble Dock (it doesn't wuite fit, but I'll probably be dismantling it again soon).[/list=1]

Although not exciting, I can now install stuff on it quickly and without too much hassle. The external drives lessen the problem of messing installations up. Got to find some ethernet card drivers.

Next: the battery!

[Adisharr]

Originally posted by stoo
Update (minor): I've successfully repaired the Duo Dock's PSU, as per the instructions around the web.

Nice! Progress!

Can you send some of that my way?

[stoo]

I'm going to get the batery cells (10x 4/5AF) on Friday from Maplin. No trouble shipping/importing and returns are possible.

My other Mac plans have suffered a major setback.

Today I got my G3 upgrade for my aging Mac (A Performa 6400). Fantastic. However, it arrived dead and took the motherboard with it. Fortunately:

• I have a spare motherboard. Not very fast, but it does.
• The card is under warranty and I should be able to RMA it.
• Replacement motherboards for this Mac cost less than £20 and complete systems are about £50 (before I sell all the bits I don't need).

Edit It works again: solution was to clean the upgrade contacts with an eraser. Sonnet technical support are great.

I've also found some higher charge cells at http://www.rswww.com.