MacBookPro screen goes black at around 30% remaining battery

My late 2013 MacBookPro 15" screen goes black at on occasion when there is around 30% remaining battery left. I can't reactivate the machine until it's plugged in to mains power. When plugged back into mains power, the screen comes back to life, it's not a restart. Before power is attached the screen will not come back. It seems to happen mostly when the computer is under load, ie. in the middle of photoshop or with a tethered camera actively working. Thanks.