Stephan Halasz

Agreed, Boric acid is a tried and true solution,  and I have a little trick I learned 25 years ago as a bug guy.   When you determine what is an attractive food source, and mix it up, try using a straw, to draw it up into.  Be mindful not to get it in your mouth, but don't freak out if you do, its pretty mild.   Once you have a full straw, cut it into about 1 in sections and place them in strategic spots where you see trails.  They follow a pheromone trail, and this helps spread the word they found "good" food.   It makes the whole job easier , with less mess.    Hope this helps!  

I am about to renew my efforts on a project like this, and a quick search online revealed this MPPT controller at a modest price.  https://www.amazon.com/dp/B0894CTHCY/?tag=cleanenergysm-20&th=1
I assume it's ok to post Amazon links here, new to the forum.  
In my past, I experimented more with old laptop chargers, or wall warts to charge, with dry cell batteries and had modest results.

I have often read in the past that deep cycling auto batteries is really hard on their lifespan.  

I look forward to reading more replies on this thread, as the more I watch going on, the more likely I think an EMP is going to be a part of the next war waged on the US.  You know, like one floating over us at 60,000 ft in a Balloon, I mean UFO.