Heaters and makeshift battery, wrong?

[Zedd]

When the power goes out I thought I could hook up a makeshift battery to a heater to keep warm but while it lets me hook the battery to the heater it doesnt turn on, am I doing something wrong?

[burger boy]

you need to fill the battery with charge first.
-- from the power outlet, while the power is on.

[Zedd]

Ahhh okay thank you!