It’s a long time ago since I’ve bought MSI Wind netbook. I’m not using it very much, because I’ve bought new MacBook, but it doesn’t mater. have two batteries for Wind, one small original 3-cell and one extra large, extra cheap 9-cell from eBay. The smaller one isn’t used too much, because it can power netbook only for 2 hours (bigger one 6 and more 🙂 ) . I’m very curious and I have Monome 128 and I hate it’s big ugly 12V power adapter, battery can be good choice, so I decided to open it. Spoiler: Battery remains usable even in netbook!! Video and howto after break!! If you like this idea, send link to this article to your favorite notebook manufacturer, maybe we can change actual state!!
– USB female connector TYPE A (Sparkfun $1.25)
– Volatage regulator 7805 (Sparkfun $1.25) or fancier and cooler 78SR Step-Down (Digikey $14.01) (thanks to Max via comments)
– wires, soldering station, hot glue etc. 🙂
About & Howto
Opening of the battery case id pretty tough, I had to use even a knife 🙂 There is a lot of ICs in battery, more than I thought, but finding source of 12V power was pretty easy. Battery has even a lot of free space, good for us 🙂
Because of lots of space, I decided to add USB charging capability (for iPhone etc.) At first, I had to decide where is the right place for connectors and cut the holes for them. Three pin connector is 12V supply (scheme is +-+, so you can’t plug it wrong way 😉 ).
I found source of 12V and solder cabels on it. 5V for usb is regulated by 7805 from 12V.
7805 regulator was pretty hot, iPhone wants 500mA 🙂 We added small passive cooler, but it wasn’t as efficient as we thought. After pluging iPhone, temperature rised up to 120′C 😀 We had to do better cooling = bigger passive. Second try cools it on 70′C. Good job!
Battery had holes in case, but they was covered by stickers. We decided to cut the sticker off for better cooling.
One more thing, close the case and it’s DONE!!! Looks like new 🙂
Full charge of iPhone 3G tooks 2hours and 22minutes. I did graph of charging so you can compare it with charging from PC Wind baterry iPhone Charge Graph 😉 After full charge of iPhone still remains 50% of juice in Winds battery!! So you can charge twice 🙂 But I think it can be even better, if you do a more efficient PCB, 7805 wich we used has lots of temperature losts 🙁
Battery can power up Monome 128, which was original idea of hack 🙂