Saturday, 29 August 2009

Usb Battery Pack - usb power pack, portable power


I've used other products when trying to extend the life of my iPod touch on long airplane flights, but this one is tops. It's small size and ease of battery replacement is ideal, and it does everything it's supposed to adding considerable life to an iPod Touch, especially when viewing videos, which can drain the iPod Touch within a few hours. No longer is that a problem. I HIGHLY recommend this product. Tekkeon TekCharge Mobile Power and Battery Charger

This is a nice little charger. I love it but only giving it 3 stars. It charges my PPC-6700 VERY slowly and can't charge my HTC Touch Pro at all. It would show the batteries are dead after 5 min of charging and the charger gets super hot. After it cools, you can charge other devices just fine with the current batteries. I've tried it with alkaline, powerex 2700 NiMH batteries, powerex imedions, and eneloops with the same results. It works great with my ipod touch 2g, PSP, cowon D2, and creative Zen. I would recommend this unit for all your MP3 needs but if you plan on trying to extend the life of your smart phone, I'd probably get a Lithium-ion version.

I have been looking for a multipurpose charger to work with the stubborn charging requirements of the iPhone 3G, and I know I have found it. I was avoiding a rechargeable battery pack, just in case that battery went dead, and I didn't like the price associated with them.



This charger uses 4 AA batteries, and can also be used to charge 4 rechargeable AA batteries. You can charger the AA batteries through the provided USB cable, then in turn, use the battery pack to charge your iPhone the other devices compatible with this charger. It serves a useful dual purpose.



Also, this is a true battery charger, not a battery extender. It actually charges the battery so you do not have to keep the charger connected to the device to use it. I would recommend this product to anyone who needs a portable USB charger for their devices.

This Tekkeon 1550 has been working very well for me. There are many detailed in depth reviews of the Tekkeon here on Amazon, so I will instead address some other issues that people seem to have.



The power unit will work as designed and will be reliable if you do not exceed the limitations of the device. Again for emphasis, do not exceed the limitations of the device and it will serve you faithfully!

(There is a Summary at the end for the main highlights)





1) Overloading the Tekkeon

Do not attach a phone or any device that will draw more than 800mAh (.8 Ah)! Yes, this means some of those Android phones with giant screens, Dual Core Tegras, etc. If your phone draws more than 800mAh it will overload the little Tekkeon and burn it out sooner or later! It was not meant to supply power for those super power hungry devices. Know the electrical specs of the device you intend to attach to it!





2) Charging rechargeable batteries in the Tekkeon

Do not attempt to recharge partially charged batteries! It very briefly touches on this in the manual and yes, they should have addressed it more. With regards to charging batteries, it appears that the Tekkeon is a simple timer charger that sends a given amount of current for a fixed amount of time and then shuts off.

If you try to recharge partially charged batteries, the batteries will get full too quickly before the Tekkeon turns off. The batteries then shed this excess energy through heat. Solution: only charge empty or near empty batteries. You should be using a smart charger (like the La Crosse BC9009 or Maha MC9000) to recharge partially charged batteries.

To be safe, I rarely use the Tekkeon to charge and instead use a smart charger. It really is better for the batteries and for the Tekkeon this way as it was primarily designed to provide power, but in a pinch can be used to recharge. If you find yourself with empty batteries and need to charge them, go ahead and let the Tekkeon charge them. It can and will safely do this. But don't use it as your main battery charger.

Lastly, if you are in a bind and need to use the Tekkeon as a charger, let it fully charge them without disconnecting it. If you do have to unplug it before the cycle finishes, do not immediately replug it back in to charge more. When you unplug it, this will reset the timer and the result will be too much charge at the end of the charge cycle as explained above.

Restated again, if you do disconnect it before the charge cycle finishes, do not try to charge them again in the Tekkeon until the batteries have been run down. Or take them out and use a smart charger to finish them off.





3) Tekkeon does not charge my smartphone/device fast enough

Modern smartphones need the data pins (D+ and D-) on the USB cable to be shorted. This lets the smartphone know that it is connected to a USB power that can supply more than 500mAh.

In the android world, most phones can sense three conditions:

a) No cable attached

b) USB power attached -- phone will draw max 500mAh

c) AC power attached -- phone will know it can draw over 500mAh

I suspect this is related to the slow charging issue. In the Fall of 2009, all of the major cell manufacturers and governing bodies agreed to standardize on the MicroUSB plug to charge cell phones. The standard also specified the shorting of the USB data pins to let devices know they are attached to a high power USB port.

My android phone detects the Tekkeon as USB power, so it draws only 500mAh from it. I am perfectly fine with it charging at 500mAh instead of 700-800. It takes a little longer, but it still charges.

For the Tekkeon to supply more current to your device, the idea is to 'trick' your phone into thinking it is connected to AC power when it is really connected to the Tekkeon. This is can be done with a `Charge Only' type cable (where the D+ and D- pins are shorted together). But do not exceed 800mAh as discussed above!! You would need to also check how you phone senses how different chargers are attached.





4) The attached device discharges into the Tekkeon

(i.e. the Tekkeon discharges my phone after it finishes charging my phone).

I suspect this happens when the batteries in the Tekkeon are near empty and it just finishes charging up the device. Best I can offer is, try to always unplug the Tekkeon from the device when finished charging OR when all three power level LEDs on the Tekkeon turn off. If there is not much power left in the Tekkeon, it will only partially charge your device and the Tekkeon LEDs will all turn off..Unplug it! Perhaps there is no one way flow regulator built in (any EE people care to chime in?). This is probably due to the fact that the Tekkeon also has to be able to charge batteries, so power flows both ways.





Summary:

1) Don't overload your little Tekkeon, 800mAh or less!

2) Don't use it for recharging batteries (use only in emergencies and with fully depleted batteries). Use a separate smart charger!

3) Be patient when it is charging or use a cable with the USB Data lines shorted, but pay attention to #1 above!

4) Unplug your device from the Tekkeon when it's finished.





P.S. I use Eneloops in the Tekkeon and they work well together. - Usb Power Pack - Battery Extender - Portable Charger - Portable Power'


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