So, does this mean I add water to the battery? I'm sort of away from home for a night and still have to drive home tomorrow, about 90 miles and I don't want to damage the car. I've not done this before, can someone tell me how I add water to the battery? Thanks!

 

The owners manual ( https://www.customers.volvocars.com/...98sv70_000.htm ) says the following: Generator Not Charging.
https://www.customers.volvocars.com/...98sv70_019.htm

https://www.customers.volvocars.com/...0_019.htm#pg20

Hope you have a good battery. It will take one to drive 90 miles before it dies. I think it can be done but do the following to increase your chances:
1. Daytime driving only.
2. No Radio
3. No heat or air fan.
4. Try not to run anything that would drain battery like GPS Unit, Windows, Wipers, Etc.

Hope you make it.

 

If you're not on the side of the road right now, get it fixed asap! Once the batt light is on, you're on borrowed time. Probably need an alt and/or alt brushes. Hope you have AAA.