"I need to charge my phone."
More literal translation is 我要给电话充电. For 我的电话要充电 it is “My phone needs charging.”
It's pretty misleading to have the English sentence 'I need to charge my phone' and demand a translation which says 'my phone needs charging'.
I makes a bit more sense to charge a mobile phone. Thankfully, "手機" is accepted in place of "電話".
Yes, indeed it does. And after a spell on this tree it is I who needs a thorough recharging!
You said "我要充電電話".
Here, you can avoid redundancy by excluding 電 to make "我要充電話" since the object is specified.
Sorry, as a Chinese from mainland China I've never heard sentences like 我要充电电话 (“phones that can be charged”?) nor 我要充电话 (fill a phone into something?). I also doubt if they are normal in Taiwan or Hong Kong.
What would you say then, if you please?