Charging problems with my Satellite L750-136

This problem has been occurring for a long time now, but I have found ways to work around it. However, things have recently gotten worse. If my battery is quite low (say, less than 40%) when trying to charge with the laptop on and running,the battery and power indicator lights on the front will turn orange and flash in unison. At this point, the laptop no longer charges and starts to deplete. It has now gotten to the point where even if the laptop is asleep or hibernating and on charge, the same thing will happen at a seemingly random point, and I will return to a fully depleted battery. Any help or incite would be gratefully received, I hope someone can help!

 

If you know this will happen when you are not using your computer, then why did you plug it in? Is there a way that you can just take the battery out, and just use the plug in? Seem to me that you know the problem is with your battery already, maybe it is time to buy a new one. If not, just take out the battery and use the power source.

 

I have tried replacing the battery, but unfortunately it hasn't helped. I plug it in whenever I'm not using it to try and keep both batteries charged for when I need to move around or work somewhere without plugs. Most of the time this is fine, as the problem with charging while off is quite intermittent. I have started using the laptop without the battery in when it is charged to preserve it, or when I need to use the laptop but have no charged batteries. It works fine, but is still not ideal.