I don't think it will ever be the same performance level on battery as plugged in because I don't think the battery can offer the same output amperage. However it should not be switching power modes constantly and something like throttlestop may be needed. Basically you should have slightly less performance on battery, but it shouldn't be awful and it shouldn't be constantly switching to the detriment of gameplay. The reason that I recommended drivers & firmware is that this is the type of problem that usually only gets fixed at that level. I doubt there is a setting you need to change because this is not desirable behavior under any circumstances.
A bus station is where a bus stops. A train station is where a train stops. On my desk, I have a work station…
