Keeping my dedicated cell phone charged

**Sonicxtacy02** · 04-04-2006, 01:05 PM

I have a samsung a670 phone in my car dedicated to on the fly internet access. Works great when i'm out of wifi range. My only problem is the data cable i have doesnt charge the phone when plugged into the usb port. So you miracle workers tell me what to do here to keep my phone charging. My idea is take the car charger i never use anymore, wire it directly to the ACC line and splice it into the power line from the usb data cable, thus chargine my phone whenever the car is on. Would it be that simple? Usb powers the phone with 5v, this would power the phone with 12v. Is that a problem. And what about the voltage from the car charger traveling back into the computer when its spliced into that 5v line? After frying a couple of usb devices in the past i wanna be sure i know what i'm doin before i partake.

**nkotch** · 04-04-2006, 01:24 PM

Definitely don't just take 12v and splice it into the USB power lines.... will definitely ruin something in the computer and possibly the phone.

Does that cable even connect to power connections on the phone? You said it doesn't charge the phone but also said that USB power the phone with 5v..... First see what voltage the phone needs (look at another charger specs or in the manual), and then figure out if the cable has wires that connect to the phone's charger/power connections.

I'm not familiar with that phone but do they make another cable that has a built-in charging port you can plug a power cable into? (Like the motorola cables, etc...) Might be easier and less hassle.

**xBrady** · 04-04-2006, 01:33 PM

Ya, I think most phones also have a usb charging cable. Maybe look on ebay. I got mine for like $6.

**Sonicxtacy02** · 04-04-2006, 01:47 PM

this cable was described as a usb charging/data cable, it appears to charge (u can see the battery indicating its charging) but it doesnt charge as i have to take the cell phone out every 3 days or so. Would the usb connection work if i just disconnected the power line altogether. I assume all it needs for data is data+,data-, and whatever the 5th cable is in the usb port. the cig lighter is gonna be enough to power the phone its built for it.

**RawsonDR** · 04-04-2006, 05:40 PM

Originally Posted by Sonicxtacy02

this cable was described as a usb charging/data cable, it appears to charge (u can see the battery indicating its charging) but it doesnt charge as i have to take the cell phone out every 3 days or so. Would the usb connection work if i just disconnected the power line altogether. I assume all it needs for data is data+,data-, and whatever the 5th cable is in the usb port. the cig lighter is gonna be enough to power the phone its built for it.

It's most likely charging, just not enough. Most devices that charge from the USB port do what's called a trickle charge, which is just a slower (less power) variant when compared to plugging it into the wall. My guess is that the few minutes of driving every day isn't enough charge to compensate for sitting on the other 22+ hours, especially if it ever sits in an area with low/no signal.

You can use your car charger as you've described. (it's made for this phone, right?) Splice it into the data cable's power line, but sever the part of this connection which goes to the computer. That way you don't have to worry about damaging your USB ports. Oh, and to be precise, the line you are splicing in isn't 12V. If it was, you could almost plug your phone directly into ACC. The car charger you have is a power supply just like a home charger, although in this case it inputs ~12V and outputs 5 or 6 Volts to the phone (in your case I think it's 6.5. It should say on the charger).

**Sonicxtacy02** · 04-05-2006, 08:10 AM

exactly what i thought would work. I'm gonna try it later today. Worst case scenario is a lose a phone i dont use anyway lol

**Sonicxtacy02** · 04-09-2006, 09:32 AM

ok i have a cig adapter hooked up to the 5v wire on the usb cable but windows will not detect the cell phone unless the 5v coming from the computer is connected to the 5v on the phone side of the cable. Please note i do NOT have the regulator connected to the car (12v). What electronic component can i add to the 5v wire that will prevent the voltage from the cig adapter from traveling back into the computer and possibly damaging the computer components?

**RawsonDR** · 04-09-2006, 03:20 PM

Did you leave the ground cable intact (from computer to phone)?

**Sonicxtacy02** · 04-09-2006, 05:18 PM

what ground? there are 4 wires in the usb 5+ data+ data- and com.

**sansoo24** · 04-11-2006, 04:00 AM

What is the model number of the cable? I had a samsung x427m (in think thats the model) with a usb calbe. The USB calble didnt charge but it had an adapter built into it that a dedicated charger plugged into. Had to get the real cable from cingular to find one that did that tho. Cost like 30 bucks and i lost the phone working on a 16 story roof like a week later...that sucked.