A serious answer - consider an MP3 player and an audio-book instead.
While sound-isolating headphones are bad for awareness, a single (ie mono) speaker can work quite well.
Personally I use two different items depending on the nature of the ride.
A small MP3 player with a build-in speaker that lives inside my helmet buff. Its quiet and invisible and ...
What is the best E-reader to use on a touring bike? What will mount well on a drop bar, withstand the vibration, and not jiggle so much that you can't read it?
Something like Google Glass (yes, The Glass is back) would be a good solution.
There are several different versions of this type of technology.
I think it's obvious that you'll need a heads-up display in order to see the road through the text you're reading. Safety first and all that.
So you're going to want to combine this project with a fairing.
The alternative is to hack your reader of choice to use a scanning laser projector, in order to paint the text on the road in front of you.
How's this for ultimate lounging - you could add a projector that projects onto the sail, not only could you read ebooks while you cycle, but also watch the occasional movie! very nice ergonomics, no need to strain your neck.
Here is a video I found which is very detailed and shows how to add a second battery to your bike:
Video: How To Add 2nd Battery to the Fiido D2
Here's the link to the battery which was recommended a ways down in the comments section:
36V 10Ah Battery Supplier
In the video he explains that you are adding the second battery in parallel. Thus both ...
IMO if you get a schematic drawing for the bike you should be able to purchase a 2nd battery and find a method to connect that battery in parallel to the original.
Having a second battery in parallel would mean both would charge & discharge at the same time. This should increase the life of both as heat from charging/discharging is a major ...
Yes in theory but the gain is not practical. You’re better off swapping batteries than trying to jury rig something.
Let’s do the calculations.
You note that the AC charger puts out 36VDC at 2 amps. That’s 72 watts per hour.
Even a modest eBike has an 8Ah battery, for a total of 36x8 or 288 watt-hours.
At 72 watt-hours per hour charging it takes four ...