Circuit design

Good day

I am planning to use the following components on my Robotic Tank (Power Circuit Only):
2X 12VDC Lead Acid Batteries
1X 12V Solar Pannel (Uses something like 13.6V to Charge the batteries)to charge both batteries)
1X PicoPSU-80-WI (12-32VDC) to my Motherboard (D945CGLF2)
1X PicoUPS 100 (12VDC) From Batteries and mains to PicoPSU-80-WI that will plug into Motherboard.

Please draw the best solution for me please on a diagramme, I thought of connecting the batteries in series to make them 24 volts (perfect for PicoPSU-80-WI), but then how will I be able to connect the solar pannel & PicoUPS 100 to charge both the batteries as these devices work with 12VDC?
Here is a current diagramme to illustrate:

Oh and the requirement is also to power the motherboard for as long as possible, so a 24VDC circuit will be ideal.
Please help me with this by saving the image at the url & edditing it in paint, or redesign it with your own software.