In the area I live power outages are common. I have looked around and ready made battery back up units that one can buy seem way to expensive for the poor performace they provide.
So here is what I did. I bought a optima gell cell deep cycle marine battery 875 CCA. I bought a charger/long term storage charger. Then a battery box and a cigertte lighter adapter.
I have used this thing for two night one one charge and it was not done yet. I bet it would go for three nights. It ony cost about a 100 dollars more to build than one of the commercial ready made backups!
That Gell cell should last a decade stored on that smart charger!
Anybody want the plans?