What is TP's voltage?

[mmtbb]

I am making a battery extender for the TP. I need to know the exact voltage that is safe to charge with. THe internal battery is 3.7v but the adapter is 5v.

Thanks

[pg2k3]

The charge Voltage is 5V like most Powered USB connections. Most HTC devices are also capable of handling up to 1Amp of current. The external power source for portable devices almost always have a higher voltage than the battery. However, theres always special power management components in place.

[theevilmonkee]

I don't know the voltage or anything, but I'm curious: What do you mean when you say that you're making a battery extender?

Thanks

[cd85233]

I think mmtbb is building a carry power charger out of batteries. I would be careful with this if I was you. I would not go over the 5V of the charger, and pay attention to the amperage. As always, amperage is what will usually do the most damage. As I see the charger says 1 Amp, seems high to me, but test your circuit thoroughly.

Good Luck.

[[sammich]]

You may want a linear regulator with a low input threshold. If you're making a power source of any kind at home, you'll need it because it will make sure your phone doesn't get damaged because it only allows 5V through.

[mmtbb]

I know that volts are constant, right (and therefor need special attention)?

However, it was my understanding that even if your batteries are 2500 mAmps, only the max of the device will go in. Is that not true?

[[sammich]]

Voltage can fluctuate with the supply's ability to output power.

When speaking of MAh, that's the capacity. But when speaking of Amperage, that is the current going into the device. Too high of a current can fry it.

[mmtbb]

In all the DIY notes I have seen, they expressed that I needed to get the volts right. I also remember being told that the amps would only give as much as the device could take. It sounds backwards to what you are mentioning. I better look at this more closely.

[zsunsun]

Easy way of looking at electronic devices are by the voltages, because current cannot exist without proper voltage. And usually device that takes charge regulates current by resistance. But sometimes among high tech electronic devices, some lack the resistance in the circuit, therefore relies the control of current to the supplying side. That is the case you want to limit the current.

[mmtbb]

quick question. I have 4 AA 1.2v 2500 mah rechargable batteries in a battery pack.

If I plugged this in to a device, what would the constant current be?