I have a Toshiba Satellite A70 laptop. Picked it up on eBay without an AC adapter. I tried several adapters rated 19v as required but shy on the required amperage. I was using a 450watt one. I noticed it would charge the battery OK when the laptop was off but once in windows it would not charge the battery. I read some threads above that pointed to anything from a bad motherboard, voltage regulator power supply or battery problem. Long story short, I bought the proper AC adapter for it, 19v 6.3amps and voila, problem fixed. It now charges in Windows. So if anyone has the same problem, that is how you fix it. Spend the money and get the right adapter for your laptop. Hope this helps someone.
This is very important to choose the right AC adapter for your laptop. The output voltage MUST be exactly the same. If your laptop requires 18.5V you must use 18.5V adapter. The amperage should be the same or higher. If the laptop requires 4.74A adapter, you’ll have to find an adapter witch provides 4.74A or MORE.