What could be wrong if the battery light came on and not long after we lost power? when we got a jump start two times it would not hold the charge long enough to even move it?

Check the battery voltage when the engine is running. You are looking for 13.6v or more, (up to 14.5v). Possibly an issue with the alternator wiring and not the alternator at all.

Dangerous practice to try & jump a near dead battery

Always try charging a battery, that is only a couple years
old & not run down more than two or three times

If the battery is dead & reads less than 12 volts, have a parts
store test it or just replace it.

Jumping a cars battery is not a fix for anything,so I fail to
see how your lost & have not addressed the battery issue,
so you can continue on with other testing,if needed

Hi dude, what you need to do is get or borrow a multimeter and check the charge firstly of your battery just battery, then start your car, you should have roughly 12volts battery, then 14volts when car is running, give your battery a voltage drop test also to see if it holds charge. What type of car is it as this is important petrol or diesel.

Will it start with a jump from another car or booster? You may just have a dead battery, or a bad alternator that isn't charging your battery. Usually it is one of the two. The battery doesn't hold a charge so it is junk. or the alternator/generator is bad and not charging the battery. Easy way to check alternator is, If the car will start with a jump? while it is running pull positive terminal off battery. If the car stays running it is the most likely the battery is not keeping a charge. On the other hand; if the car stops running when you pull the terminal off the alternator isn't providing enough electricity to charge the battery or run the car.

There is also the possibility nothing is wrong and you left the interior lights on all night.

OLder cars YEs you can jump it without a battery. But in newer cars that use computers and advanced Eltronic ignition/timing/ful injection you have to have power to the cars computer. without a good battery the car will not run.---------------------------------------------------------------------------------
Renault CAN Clip

You have a alternator going out if you get the car going pull the + cable off if the car dies right away the alternator is bad . (Ase) cert auto tech

Depends.
If the alternator is charging, and the battery will not hold a charge, I would suspect the battery.
If the alternator is not charging the battery, I would look at the fuseable links and connections.

Sounds like your alternator is not charging or your battery is not holding the charge. Have them both checked out for free at Pepboys or Autozone.

Maintenance-free batteries really don't tolerate complete discharge very well. If the battery was already several years old, letting it go dead probably was the last straw, so now it may not hold a charge more than a day or two, or it may have so little capacity that if you start the car a couple of times without a long (20 min+) drive between starts to recharge the battery, it won't be able to start the car the next time without a jump. Probably time to go battery shopping.
You didn't mention your model, but many BMWs use unusual battery sizes (group #s). Most of us use a smaller, common size battery, or a larger (longer) battery because original sized batteries are hard to find at the retailers, and when you find one, it may not be very fresh. If your battery will only last six or seven years at best, you don't want to buy one that is already a year old, and has been sitting on the shelf partially charged for that year.

if its not the battery sounds rto me like it could be the alternator. it holds power when something else is hooked to it but when removed it stalls out and has no power. sounds to me its not holding charge. if the battery was dead the alternator would hold charge if you jumped it but its not so check that out. go to a local orielly or autoparts store an have them check it on a computer. wish ya luck