Solar charging of electric bike

ok now that the electric bike is functioning with feedback on speed and battery status what's next?
Walmart had these solar chargers on sale
https://www.walmart.com/ip/Rayovac-High-Performance-6V-Solar-Battery-Charger/37424618

for $10!!!

We got two of them because only two were available :(
Now two of these in series can charge the 12V batteries...

May have to put in some safeties so that we dont fry the batteries (the bike is 24V with two 12V in series and would have to charge them in parallel)

Electric Bike enhancements

The first thing Rithvik wanted was to know was how fast he was going!! what is it with boys and speed and fast cars and trucks? Adwait suggested we add a battery status as he was thinking how far can I go and return without the battery running out. Recall the battery was sized for 30 min but we dont keep track of long it was run before fully charged.

1. Speed: A simple hall effect sensor on the spokes and a magnetic pick up to time between pulses and with diameter of the cycle known we know the speed. Thankfully someone has already built this device with additional info such as time, distance.
https://www.amazon.com/gp/product/B0792YQ65C/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

2. Battery status: From almost 20 years ago battery modelled as a huge capacitor and internal resistance and SoC (State of Charge) can be determined from voltage and current.  A lot of info can be estimated purely from battery voltage and such a device exists for 24V.
https://www.amazon.com/gp/product/B01E0SDTBO/ref=od_aui_detailpages00?ie=UTF8&psc=1

Now we know how fast we are going and how much energy we have left Yay.