Solar in a box

How to power electronics on the go, those that are a bit more power-hungry than a smartphone, maybe a synthesizer with a small PA? A power pack with a solar panel and a charge controller built in should work... Here is what I made:

A small solar panel (10 Wp) charges a lead battery (gel / 12 V / 7.2 Ah), via a solar charge controller (Steca PR 1010). Output voltages are:

• The battery voltage, 11.5 to 14 V, depending on the state of charge, (on 1 car lighter socket)
• 9 V, provided by a DC/DC buck converter, (on 4 barrel connectors)
• 5 V, provided by a DC/DC buck converter, (on 2 USB A connectors)

There is a power meter on each output, showing: voltage, current, time connected and mAh. Each voltage/converter can individually be switched on/off, by the red switches. The green switches are:

• Connect/disconnect solar panel to charge controller
• Connect/disconnect battery to charge controller
• Connect/disconnect fuse block (to which the loads are connected)

I like these stackable and rugged swiss RAKO containers (which are available with a handle), so I built everything into one.

Clearly, the heavy weight of this box is a major drawback, and I'm looking to replace the lead battery by a different chemistry that provides the same or higher capacity in a more lightweight package. Also, the charge controller (from about 2012) is a PWM type, not MPPT, which means that the already small 10 W solar panel isn't used in the most efficient way. But the overall concept seems valid and I will continue to work on this...