The standard lead battery clamps on almost all PSA vehicles are a waste of space. They cause problems with poor charging and poor starting, will stretch over time to come loose, and have been known to come off completely.
I hate them. If you do too, do this:
The negative clamp on my BX was suffering from dissimilar metal corrosion from the steel bolt. It would come off the battery simply by sneezing nearby. It had to go.
So you get one of these. It's a standard rubbish cheapo battery clamp from any motor factors (or dare I say it, even halfrauds) Note that the screws that normally clamp the cables have been removed (as this is the reason why they're normally rubbish.)
Hack the old clamp off the cable. Not difficult since it's lead. Cut back about an inch of the insulation on the cable.
My replacement clamp was a very cheap small one, and the hole for the cable wasn't big enough. This is it being drilled out.
... and having a countersink put on the cable entry to make it easy to get the cable in.
Cable inserted into clamp.
Now, I don't have photos of the next bit, so bear with me. You'll need a blowlamp, some plumbers flux and plumbers solder. Dip the ends of the cable in the plumbers flux and then assemble as the photo above. Now heat the clamp up until you can feed solder in through the holes vacated by the cable screws. Feed in solder until it drips out from somewhere, then allow to cool.
What you will then have is a nice soldered joint into a brass battery clamp. Way better than the PSA type.
And that's the result. You can now do this clamp up tight without worrying about stretching it, or having the bolt/nut pull all the way through the clamp.
Note that I've used an M8 nut and bolt in this clamp. There's a good reason for that: the standard square-head bolt used on these clamps is a 1/4 Whitworth, which although I do have the correct spanner for, I don't carry one in my "emergency" toolkit. I do, however, carry a 13mm.
Having done this the engine cranked noticeably faster. I can only imagine how hot the terminal was getting during cold-starts.
