Charge Cell Phone From Throttle? (Ezip)

[JerryScript]

Would it be possible to tap the throttle's 5v to charge a cell phone while riding?

I like to use Google Navigation while riding, and listen to music. Unfortunately, my bike mount for my phone makes it to where I need to keep the screen brightness turned all the way up, and of course the screen stays powered all the time when using it on my bike. Since it's an android phone, this sometimes leaves me with a low battery on the phone. So I would like to charge my cell phone via my Ezip's electrical system. I don't want to use one of the generator based charging systems available on the market.

Would it be possible to draw .5a from the throttle's 5v line to power the cell phone?

If this would mess with the throttle like I suspect, could anyone suggest where I can draw the necessary current from? My phone (LG Optimus V) uses less than .5a to charge, and about .7a when charging and in use at the same time (This is from info posted in the androidcentral forums, not from personal testing, I'm waiting for a new multi, mine had a storage "accident"). I don't need a full charging draw, just enough to keep the battery relatively topped off while in use.

 

[neptronix]

Amberwolf would know for sure, but here's my guess:

I would think that the throttle signal would have a big voltage drop from half an amp being drawn off of it. This would lead to a lower signal going to the controller. Also, the controller is not meant to supply that kind of current so you could damage it..

A much better way to do this would be to use a DC-DC converter.

 

[shorza]

I'm not sure what voltage you are running, but I'm running 72 volt and that is enough to power my phone charger, but less volts may not work.
However I am not using it to charge my phone, but to power my headlight torch.
Input is 72 volts dc
Output is 6 volts dc, 1 amp.

 

[JerryScript]

I'm running stock Currie Ezip 24v.

According to testing done by a poster at androidforums, the phone uses less than 0.4a in most cases, so that's all I need to prevent the phone from draining. It would be great to charge it, but just maintaining the charge level would be terrific.

 

[amberwolf]

I don't know what the max current your controller can provide on the 5V line is, but I doubt it can put out a lot more than what the controller internals, throttle hall, and the motor halls already use.

As others have, I'd recommend the DC-DC converter route. If your battery pack is 48V or higher, it is highly likely that your wall-plug AC charger for the device will actually work on the pack itself. Many small adapters like those that I have tried will work on as little as 30VDC once they've been kickstarted at a higher voltage, like 36-40V or more. Some will not work on less than 50-60VDC or more, but most will.

The only catch is that they may not be able to put out as much current as they did running off the wall, or may get a lot hotter inside while trying, and might require their cases removed or at least ventilated.

So the original charger, if it can only put out the 700mA the device needs to run and charge at the same time, may not be up to it. You might want to instead find one that can do at least 2A or more at the same voltage. These things abound at Goodwills and other thrift stores for a buck or two, if you're patient and keep an eye out. Even if it has the wrong connector you can just splice one off the right kind, if you just make sure to measure the connections first.

 

[dogman dan]

Wouldn't it work while the bike was not riding? The othe option assuming you have a lithium battery, would be to tap one cell group. It would of course unbalance the battery some, but not by too much I'd think.

 

[JerryScript]

So, I might be able to use a wall charger, never thought of that.

I have ordered a set of batteries and charger from a china ebay seller (did my research, it's a good buy). Once it arrives, I'll see what the charger internals are like, and maybe order another one to try and mod. (hate waiting on shipping from china)

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280658529272

 

[miuan]

Yeah most wall socket adaptors will work, but not all. Especially the old school transformers i.e. non switched adaptors, will never work with DC, regardless of voltage.

 

[auraslip]

Hi,
What I did on my bike is us a 12v dc-dc converter that I sell for $30, and then a standard automotive 12v phone charger to drop that down to 5v. These are available at $1 stores.
It was a little bit of work, but is very useful to have.

I attached a female usb plug to the out put.

the 5v dc-dc is the tiny circuit board.

 

[Hillhater]

Isnt it possible to simply use a $5.00 UBEC ?
0-26v, to 5 v X 5A out
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10312

 

[auraslip]

I think a fully charged 24v lead pack would be over 26v. OTOH there are lots of cheap 5v dc-dc from Lyen or on ebay.