Help w/ low battery indicator please

[KSM74]

Any help is appreciated,

I have a 11.1v battery system, an I would like to install a low battery indicator. I would like the indicator to be a single red LED that initiates when the voltage drops below 7v. Size is definitely a concern here.

I have looked online at various templates, but I just can't find what I am looking for. I admittedly only know enough about electrical circuits to get myself in trouble. I suppose the main question is; what type of components should I use? I'm not sure I know how to do the math to get the threshold set at 7v.

 

[mgb_phys]

Just an op-amp and a zener,something like
http://www.reuk.co.uk/12-Volt-Battery-Low-Indicator-LM741.htm

Maxim (and others) make specific battery monitoring ICs

 

[KSM74]

Just an op-amp and a zener,something like
http://www.reuk.co.uk/12-Volt-Battery-Low-Indicator-LM741.htm

Maxim (and others) make specific battery monitoring ICs

Yes, thank you. I'll check out the ICs