not enough juice - power inverter

The *time* you are able to run anything for any length of time is solely dependant upon the size of the battery you have, and what the manufacture has stated it as. 1. Amp Hours (AH) = An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps X hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) X .333 (hours), or 6.67 AH. The accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured. Sometimes ratings at the 6 hour rate and 100 hour rate are also given for comparison and for different applications. The 6-hour rate is often used for industrial batteries, as that is a typical daily duty cycle. Sometimes the 100 hour rate is given just to make the battery look better than it really is, but it is also useful for figuring battery capacity for long-term backup amp-hour requirements 2. Reserve Capacity (RC) = The reserve capacity of a battery is defined as the number of minutes that it can support a 25 ampere load at 80°F until its terminal voltage drops to 1.75 volts per cell or 10.50 volts for a 12V battery. Thus a 12V battery that has a reserve capacity rating of 100 signifies that it can be discharged at 25 amps for 100 minutes at 80°F before its voltage drops to 10.75 volts. So to answer your Q. You cannot run your rice cooker for any reasonable amount of time with just the battery you have. You will need to either run the vehicle, or use a power generator for the application you are asking about. Or simply do it like most people do in the sticks, build a fire or use a propane / gas unit. Regards EVIL Teken . . .

Or do what semi-trucks have and install a bank of six batteries or so.