So many times I have witnessed people using an anchor windlass incorrectly and doing serious damage to them. Typical anchor retrieval speeds are around 30ft/minute at around 200 lb loading, and higher loads will cause a slower anchor retrieval rate. Windlasses do not have a constant load during anchor recovery, but have a varying load according to the various phases of anchor recovery. When operating your anchor windlass please observe the following practices.
The first phase involves slowly motoring up over the anchor so the recovery rate will be at a maximum speed. This removes chain tension and makes recovery quicker and less load on the windlass electric motor. The engine alternator supplies a good part of the motor windlass load and keeps the motor from impressing a large voltage surge (brown out) on the electrical system, and more importantly keeps the voltage from dropping too low. The same technique is used by big commercial ships as well.
The anchor windlass should never be used without motoring, the voltage drop can be severe so that a drop in power occurs after only a few minutes as even batteries have a hard time coping with such loads. If the anchor becomes fouled take the load on the chain-stopper and use the boat to break it loose and then resume retrieval.
The load will steadily increase as the tension increases towards the anchor breakout point. At the breakout point maximum current will be drawn for a brief period, and this current peak may be as high as 2-3 times the rated current.
Once the anchor has broken out, the load drops as the windlass hauls the anchor vertically back to the boat. If you are having a problem with anchor retrieval, do not continue to load the windlass to stall conditions without stopping every few minutes, and allowing the motor to cool down. The motor may overheat due to the lower voltage causing damage or even burnout.
Most manufacturers publish performance curves and they illustrate the effect load has on power consumption and the subsequent reductions in hauling speeds. A point can be reached where the windlass electric motor will overload and stall. The higher the load the windlass is operated at the shorter the operation time allowed on the motor as the higher currents overheat the electrical motor windings and can burn them out. So don't go trying to haul anchor and pull the boat in, motor up slowly as you retrieve and reduce the loads. Motors have a duty cycle and operating at full rated load means a shorter available operating time. More anchor handling information and windlass advice.