[tafische]

I have the nead for an emergency charger when I am not around any power source (car, plug, etc).

I was thinking about using 4 AA batteries and a 7805 regulator. Cut off a usb cable and wire up the power. (They would have to be regular and not rechargable 1.5x4 = 6V, 1.2x4=4.8V)

Anyone ever tried using a BB this way? See any reason why it would not work? It would cost about $5 plus batteries.

[jbairdjr]

I have not tried this, but would be interested if anyone has done this.
I think a simple how-to would be excellent. I know it would be nice to put something in my briefcase or bag, "just in case."
I would worry about the correct power input, though.

[Nextel User]

i have seen emergency chargers for the bb in ads. check google. they do exist

[DavidE]

This might fit your needs, though it's not a charger. It's a replacement power source that uses a single AA battery. Unfortunately, the ad copy doesn't indicate if the "assortment of connectors" includes a BlackBerry (USB) connector. Here's the link: http://www.herringtoncatalog.com/es328.html.

DavidE
www.davidenglish.com

[DavidE]

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[tafische]

OK...so I made my charge kit today and it has good regulated 5v out.

Problem - it charges for about 5 seconds then stops. Apparently the BB is looking for something else on the USB port to keep the charge active. I have seen this before trying to use another charge that came with a music player. I thought it was a bad charger, but now it appears I was wrong.

I have a BB car charger and plug in charger from Cingular that work fine, so obviously they are doing something with a data line or something to makes it keep charging.

Any ideas?

[jscully]

Yeah, try getting a spare battery. It will be considerably less to carry around...
I have a second battery, and it is always charged. If I'm going to be away from my truck for a considerable amount of time, I put the spare battery right in my wallet, and just switch it up if need be.
It may seem more expensive at the start...but it will save you $ in AA batteries and an entire unit replacement...

[tafische]

It is all about the hunt my man... ;) .... Not I am determined to make it work!

[aau007]

You need current regulation. Charging Li-Ion battery requires constant current in the beginning and, once the battery reaches 4.1v, constant voltage to top off. There is also current regulation inside the unit. If the charging current is too high, it will cut off the charger to prevent damage to the battery, and thus the unit. Too high a charge current to Li-Ion battery will cause the battery to explode.

[VR6]

it's not just the 5V from the USB that charges the BB...if you do not have the desktop manager software installed, it will not charge...

[merlinw]

I think finding a way to charge it with "AA" batteries would be a great idea, after a disaster, AA's are a lot easier to find than a plug.
We all know that the BB doesn't need a computer to charge the batt. I charge mine from a AC outlet. So if it works that way, anything is possiable.
Maybe I'll take apart the AC adapter, and see how it works.

[tafische]

I think aau007 may have something. I would have thought the charge circuit in the BB would have limited the current, but maybe not. I looked at my MP3 charger and it is 1000 mA instand of 500 mA.

A standard USB port is limited to 500 mA, but the battery supply can go much higher.

I need to put together a basic current limiting circuit and try again.

My other option was to build a 12v battery pak using 8 AAs and use my car charger. The only problem there is so much power is wasted converting it back to 5v.