I am having problems with my electric 1985 Still R60 EFG 2,5/6013. Has been working fine up until yesterday when it suddenly lost power.

It still drives, but with reduced speed and accelerator pedal has to be floored for it to move. It has also lost a lot of power and seems to want to stop when carrying load.
Hydraulics and steering are working fine.

Does anyone have any good ideas as to what this could be?

Thanks,
Sean