Couldn't find this anywhere on the forum so thought I may as well contribute! This is a how to for Mk2 Leons with the rubbish fabric battery box to replace with a nice shiny plastic one. There may be other ways of doing this, but this method worked for me.
1. Get the plastic box from Dave at Sere Motors who is on the forum. He's a top bloke and will sort out this for you for a good price. The box arrives in three bits. Bit one is the back side, bit two is the front side, and bit three is the lid.
2. Open bonnet and remove air box / move your air pipe out of the way.
3. Undo battery strap on the engine-side of the battery. Something like a 12mm socket should do the trick but check for yourself to make sure! Watch you don't lose the metal strap as it can fall down the bay.
4. Disconnect your earth cable (10mm socket to loosen). Then remove the positive cable plastic protector and chuck it. Disconnect the positive cable. Take care and remove the very heavy battery. At the same time take the cacky fabric casing off.
5. Take the rear half of the new box first and place into position (the one that is closest to the firewall) - it doesn't exactly snap into place but it should be snug with the plastic base in the engine bay. If you can do this without removing the battery then kudos to you - I couldn't as it's VERY fiddly!!
6. Time to put the battery back in place. Replace the strap and tighten.
7. This next bit is fiddly - you have to re-bend the positive and negative cables CAREFULLY (doesn't need a lot) so that they can be re-routed along the new box. The positive cable will be going into a small hole at the bottom of the front side and work its way up along the battery to the terminal. The negative wire will need a little persuasion to run along the top back edge of the battery box.
8. Attach the front side of the battery box to the rear section making sure it goes over the positive cable. You will see there are grooves either side where it fits neatly. Two tabs on the very bottom of the front of the box can be pushed into two slits at the base to hold everything into position. Ensure the positive cable routes as best as you can into the small hole.
9. Reconnect the positive wire, and reconnect the negative wire firmly to avoid sparks.
10. Put the lid on, re-position the air pipe / refit your airbox and admire your work.
11. When first driving, a few warning lamps on the dash will light up for the first 10-20 metres of driving but then will extinguish as it re-calibrates itself from the battery disconnect.
1. Get the plastic box from Dave at Sere Motors who is on the forum. He's a top bloke and will sort out this for you for a good price. The box arrives in three bits. Bit one is the back side, bit two is the front side, and bit three is the lid.
2. Open bonnet and remove air box / move your air pipe out of the way.
3. Undo battery strap on the engine-side of the battery. Something like a 12mm socket should do the trick but check for yourself to make sure! Watch you don't lose the metal strap as it can fall down the bay.
4. Disconnect your earth cable (10mm socket to loosen). Then remove the positive cable plastic protector and chuck it. Disconnect the positive cable. Take care and remove the very heavy battery. At the same time take the cacky fabric casing off.
5. Take the rear half of the new box first and place into position (the one that is closest to the firewall) - it doesn't exactly snap into place but it should be snug with the plastic base in the engine bay. If you can do this without removing the battery then kudos to you - I couldn't as it's VERY fiddly!!
6. Time to put the battery back in place. Replace the strap and tighten.
7. This next bit is fiddly - you have to re-bend the positive and negative cables CAREFULLY (doesn't need a lot) so that they can be re-routed along the new box. The positive cable will be going into a small hole at the bottom of the front side and work its way up along the battery to the terminal. The negative wire will need a little persuasion to run along the top back edge of the battery box.
8. Attach the front side of the battery box to the rear section making sure it goes over the positive cable. You will see there are grooves either side where it fits neatly. Two tabs on the very bottom of the front of the box can be pushed into two slits at the base to hold everything into position. Ensure the positive cable routes as best as you can into the small hole.
9. Reconnect the positive wire, and reconnect the negative wire firmly to avoid sparks.
10. Put the lid on, re-position the air pipe / refit your airbox and admire your work.
11. When first driving, a few warning lamps on the dash will light up for the first 10-20 metres of driving but then will extinguish as it re-calibrates itself from the battery disconnect.