Is there a way of feeding power FROM a laptop battery thru a house ac cable INTO anot

like some type of two way battery charger that will feed power OUT of the laptop battery? or a step up transformer package?
I know that this is unusual and that charging appliances from small batteries is difficult wastes time and power etc., etc., want to do it anyways for a special reason, I have a large item charges off a house socket and want to charge it from my laptop battery while camping.
anybody help? much thanks if so

What's the large item?

An inverter can produce 120vac from a dc power source. Ones running off 12v are readily available at any auto parts store, etc. Unless your load is very light, I would not expect a laptop battery to last long in such an application. Buy a deap cycle 12v battery, an inverter, and a charger for the battery. You'll find it much cheaper than frequenty replacing the laptop battery.

an inverter on a laptop battery would not work at all, they are limited to very low current output (below 10A often). The only thing you could recharge are usb devices from laptop usb port