Land Rover Repair: 2003 Range Rover HSE - battery light to ..., range rover hse, 2003 range rover hse

Question
This morning I noticed I had left my lights on for a several hours (5-7). When I started the car every thing was fine. Next time I started the car again 6 hours later again no problems. 18 more hours later wehn i started it again the battery light was on. I ignored it for the time being turned the car off after 3 mins of driving. Started it back up 30 mins later, light was still on. Started another 1 hr later and with in one minute of driving dash diplayed "Trans. Fail Safe Mode " then i felt something in the trans mission at low rate of speed so i pulled over into a gas station. The gas was also quite low so to be sure that was not the problem I filled the tank which in turn required me to again shut off the car. I started it back up and then i got the same message "Trans. Fail Safe Mode" , it was followed by "Air Susp. Inactive" , "HDC Inaqctive", and the HDC light was displayed in the dash (not blinking and wouldn't turn off if I hit the HDC button) along with the battery light which has remained on each start since the intial occurance; I read manual and it said avoid high revs and contact service specialist, so I headed home about 4mi. I tried leaving the car running in the garage for a while (30 mins) and when i came back out to check on it the car was off. I started it again and felt the car possibly mis-firing? Engine idle became very rough and shook the whole car... I turned the car off and have not touched it since.

Could all these problems be because some of the systems are not getting enough voltage? Could it be just the battery or is my trans. ruined?

HELP!

Thanks Very Much for you input!

Answer
Yes, low voltage can cause meny mysterious problems. The systems are using much power, so if you don't  have charging the battery will go dead in about 1-2 hours.
So, if the voltage falls under about 10-10.5 volts theelectronic systems switches to safe mode.

You should check the battery voltage (with a multimeter) at 2000-2500 revs with all lights on, and you have to measure at least 13.3-13.5 volts min.

If it's lower than 13 you have to go to any workshop and ask them to repair the alternator.