I've tried making a battery pack for a Firewire HDD (fitting on a VAIO - you may know they i.Link doesn't output 5v). It works great so far... No burning smells (I've had about an hours worth of use so far, now doing a Scandisk on a 30Gb disk to check how long it'll actually last). It works with 8 1700mah AA NiMh cells, on a 4-serial x 2-in-parallel layout. Theoretically speaking, I should get about 4 hours of use out of the thing as the enclosure is rated for 1A with the drive, but is probably drawing about 500-750ma altogether in operation.
However, I've realized that the finished article is nearly as big as, and quite possibly heavier than, the Firewire HDD!
To be honest, I can live with it - but I was wondering if it was possible to use Li-Ion cells to reduce weight and size. Is it possible? How would you go about making a 5V Li-Ion cell which can pack around 3000mah?
Other questions are about a battery meter and an 'in-situ' recharger.
As things are now, I'll have to take the AA batteries out to recharge them. It is possible to charge the batteries fixed in the above configuration? What kind of circuit would I have to make (with overcharging protection?)?
And it'd be mighty handy to rig up a battery capacity meter to tell me how much juice there is left - something like a 4-segment LED bar display or something - can someone hook me up with some circuit designs?
However, I've realized that the finished article is nearly as big as, and quite possibly heavier than, the Firewire HDD!
To be honest, I can live with it - but I was wondering if it was possible to use Li-Ion cells to reduce weight and size. Is it possible? How would you go about making a 5V Li-Ion cell which can pack around 3000mah?
Other questions are about a battery meter and an 'in-situ' recharger.
As things are now, I'll have to take the AA batteries out to recharge them. It is possible to charge the batteries fixed in the above configuration? What kind of circuit would I have to make (with overcharging protection?)?
And it'd be mighty handy to rig up a battery capacity meter to tell me how much juice there is left - something like a 4-segment LED bar display or something - can someone hook me up with some circuit designs?
Facebook
Twitter