Battery leads corrosion

[festerpig]

Greetings to all your E34 folks.I just took delivery of my E34 M50B20. Bought from a dealer here in Sillyland. First thing I noticed was that both the battery leads (+ve and -ve) have got quite a bit of white powder around the leads - I take this as a result of battery corrosion. Also the -ve lead cable have the rubber casing starting to peel. The battery is not 'original' it has to be some cheapo battery that the dealer put in.My question as follows:1. What causes the battery corrosion? I have seen another 2 E34 for sale that have a similiar problem. Is this normal or common on the E34? If not, could one of the causes of corrosion be that the battery is of the incorrect size and hence has to work 'extra hard'?2. I want to remove the leads and clean it to remove the white powder and also check the size of the battery - can I just disconnect the battery and do that and reconnect after that? Will I mess up the onboard electronics? My E34 does not have check control and OBC from what I can figure out.Any advice appreciated.