Hi @buraktanriverdi, welcome to the forum 
There are some current-/thrust- limiting options discussed here that may be of interest.
Limiting current by limiting thrust reduces the total thrust capacity of the vehicle, which makes it less capable of being controlled in fast-moving water, and reduces the maximum travel speed in general. That said, if the current needs to be limited to avoid damaging the battery, or the vehicle restarting due to under-voltage of the control electronics, then allowing a higher current capacity likely wouldn’t help anyway.
How much you limit things depends on your requirements. If you want to be able to always have enough current capacity for any type of control then you may need to limit thrust in a way that also limits the thrust output when you are only using some thrusters, which may result in more restriction than is entirely necessary. If instead you’re ok with careful control to avoid over-drawing then you can get a bit more performance, but if you’re not careful enough and drive the vehicle too hard then it may lose power unexpectedly, particularly while stabilising in fast water.