Ewerk and iphone
 

Cross posted in the Electronics, Lighting, & Gadgets forum.

Ok, so I'm going to bite the bullet and get myself a dynamo hub. I'll be using it primarily as a power source for my i-gadgets when on tour - primarily my iphone 4 and my ipad 2. I will use a B&M E-Werk to regulate the voltage/ampage from the hub to my iphone. Was just about to buy it all and then read something about the variable voltage not being able to charge the iphone 3GS without the use of a cache battery. The cache battery is another cost in what is becoming an expensive upgrade and I'd rather not get one if I can get away with it.

So, question is can the dynamo hub ---> e-werk ---> iphone 4 (NOT iphone 3GS) charge my iphone and run my gps app while riding without the need of a cache battery?

Thanks.

the interface is the USB cord standard.. 5.5v , as others said..

A reader of manuals , I learn from reading them online .. try it..

might have to know the load on things running, and perhaps, turn them off
to catch up with the charge vs discharge, rate ..

I have no cell phones smart or otherwise, just use the IGH for lights.

My experience here is with the Biologic Reecharge, not E-Werk, but similar situation....

The issue is NOT voltage, but amperage....

While a cache battery is an additional expense, it really smooths out the charging process, while adding a little weight and inefficiency. Without the battery, every time the current drops (as you slow) the iPhone squawks as the charging starts and stops. This drove me nuts, so I got the battery. With the battery, your dynamo is always working usefully, charging the battery which is charging the phone,etc, and/or running lights.

Hope that helps you decide.

Math : I = V over R. http://en.wikipedia.org/wiki/Ohm's_law

Ie; its all related ..