Ok, that might be really too much but was wondering if you could build a battery pack from laptop/mobile phone lithium batteries. Would it be able to be managed properly or too much hussle/problems?
Is there a part here in the forum for Tricks'n'Tips from the scrape yard. I mean there is so much trashing. For example you could easily get a charger made from there. I found almost brand new batteries, etc. I guess there are so much valuable things in our trash and we don't even know it.
Making yourself independable should be at any cost(as low as possible)

and asap.