Battery, terminals, case and cables

• Apologies dear Reader- I have reworked this blog entry to remove much of the repetition and bitterness over incorrect materials and wasted time!
  
  
  The battery in the Excel is a type 067 but type 027 has the same dimensions and offers improved performance. I bought an Exide version for about £50 which should let me use the original battery strap and cover with its newly installed replacement turnbuckles.
  
  I also have a problem with the battery cables- largely of my own making! I had got quite fed up with constantly attaching and re-attaching the battery terminals, so I removed these (the neg was soldered and had to be cut off) and fitted a pair of Halfords quick-release terminals. This was an error! Those terminals do indeed grip and release the battery posts in a convenient fashion; but the grip to fasten the battery cable is very poor. In general there are three acceptable ways of fastening a battery terminal: Solder, Crimp or use a screw on terminal where two screws penetrate the conductor wire. Soldering is best but I worry about doing this in position. I don't fancy naked flames anywhere in the boot or near the tank. Crimping is to my mind safer on the car, and seems to be of two types- a socket that is crimped around the wire using a hexagonal crimp, or two wings which are folded and crimped in on top of one another using an Anderson crimper. Crimped terminals are sometimes soldered as well giving a good solid joint with excellent conductivity. Sadly the Halfords terminal uses none of these methods. Its a simple screw clamp rather like the cable grip found in a domestic plug: The screws are puny and don't penetrate the copper conductor. If the cable is under any strain at all it just slips out of the clamp!
  

  

  Quick release battery terminal- Wire clamped in grip plate by a screw at each side- its pulled out again

  
  

  

  Top view

  

  "cable grip" style very puny clamps

  
  The negative cable provides the only connection between battery and car; everything electrical earths eventually through this contact so its vital to keep it in good order at both battery and chassis terminals.
  
  At the battery end, my cable is now just a few inches too short to reach the terminal without strain and keeps pulling out. I can either replace it or extend it, and as extending it is cheaper I will try that first. Lotus used copper cored  battery cable. The copper interior is 8 mm diameter and the cable including insulation is 10mm diameter. I realise that this gives a predicted copper area close to 50mm2 but I ordered some of that and it was far too big... the wire seems to be 35mm2..? This I later discovered is a common confusion. Even some suppliers will send the wrong size cable. As a working assumption I now assume all multistrand cable is actually the size below its measured and calculated size because of the gaps between the strands, although the disparity does reduce as the cable size decreases. So a bundle sized at 70mm2 is probably 50; one sized at 50 is probably 35 and one sized at 35 is probably 25! I ordered new cable, solder-or-crimp-on terminals for both positive and negative battery connections and a butt joining  sleeve to connect a short extension to the cable. I also ordered new terminal covers as my existing were split.
  
  Battery Post Terminal
  I bought a Chinese made hydraulic crimper from Ebay- seems to be similar to the harbour freight model although 8 ton rather than 10. This was very cheap at £15 and should be fine for the occasional use I envisage. I also bought some 35-50mm terminals both battery bolt on type and eyelet fixings.
  

  

  8 tonne hydraulic crimper

  
  

  

  Butt joining tubes

  
  From the foregoing it should be clear that it was my intention to do this job "properly". In the event, it didn't turn out that way. Firstly I trimmed the wire to fit the new terminal-cutting back the insulation over the length of the socket.
  

  

  Insulation stripped from wire to depth of socket

  
  I could then slip on the terminal cover and the heat shrink needed to finalise the terminal...
  
  
  ...and then I tried to crimp it! There are several videos online and the crimper I bought is similar to that sold by Harbor freight (USA) and others- although mine is only an 8 tonne version. Most videos are from the US and state all wire sizes in AWG- for both wire and terminals. Great if you buy your materials in AWG, but in the UK they are sold by cross-sectional area.
  
  My initial experiences weren't good. This was largely due to mismatches between cable, fitting and die size. Although a 35 cable does fit easily into a 35-50 post terminal I found that it was virtually impossible to crimp tightly enough to hold the cable and when I did so the terminal promptly fractured. I will investigate the right way to crimp these terminals but in the meantime I was able to reconnect a new bolt-on type terminal. I also fitted the new battery and  and although the cable is stretched, it could reach the new battery (Exide Premium EA612 Carbon Boost 61Ah 12v Type 075). Thus for the first time I was able to fit the battery carrier, cables and cover to finally neaten up the boot.
  

  

  Installing new battery and restored clamp- new turnbuckle female halves (these are cheaper if you buy Range Rover turn fasteners)

  
  

  

  ... connecting...wire a bit tight still.

  
  

  

  Case installed

  Well it looks nice and the starter motor turns with more ooomph now!! The cable is still too short and once I get more terminals and solve the crimping problem (or solder the post terminal on!) I will extend it to make a more comfortable fit. I will update this blog at that point but since I'm also waiting on getting the car up on ramps to get at the chassis connection and exhausts (see below) I thought I'd post now and update later!
  
  Crimping Revisited!
  For what its worth my experience:
  What follows has been gleaned from my extensive experience of at least a week, two lengths of cable purchased and about half a dozen terminals destroyed! It may help you, but bear in mind it may be/probably is wrong! If anyone can supply a more accurate guide then I will be delighted- send me a comment or PM me and I will be happy to put it here.
  
  I had several attempts but this is what worked for me... If you don't want to read my painful voyage then here is the conclusion!
  
  
  • Use SEIWA tin plated brass terminals
  • Use 7mm ID terminals (25mm2) and connectors for both 35 and 25mm2 cable.
  • You may need to neaten a 35mm2 strand bundle with a 16 or 10 die before it will slip in.
  • Crimp battery post terminals with a 25mm die
  • Crimp 35mm2 cables in butt and eyelet terminals with a 25mm die
  • Crimp 25mm2 cables in butt and eyelet connectors with a 16mm die.
  
  For anyone more interested in what I actually did then the account follows...
  
  Post terminals- I bought tin plated brass SEIWA terminals in 2 sizes specified by internal diameter 7mm and 11mm from nnc-tuning (eBay). I did try other types but they cracked- possibly due to my error. These worked and I'm sticking with them in future. The 11mm was really too big for use on this car.
  
  
  Two post terminal sizes, sold by ID; 11mm on left, 7mm on right
  
  
  

  

  Smaller terminal ID 7mm

  
  

  
  

  

  and OD 11MM
  

  
  

  I tried to ID the cable size I was working with- this is the  cable I was sent as 35mm2. The inner bundle diameter is 6mm and the cable outer diameter (inc insulation) is about 8mm. This gives a calculated area of the core as 28mm2 and I suspect its really 25mm2 cable. In any event it would slip firmly into the smaller 7mm ID terminal with minimal compressing
  
  

  

  Internal diameter of copper bundle 6mm. 

  
  

  

  External diameter inc insulation 8mm.

  

  Cable inserted into 7mm terminal

  The cable I had bought would fit comfortably into the 7mm terminal, but how to crimp? The recommendation is to use the same size die as the cable area, but perhaps its better to consider the terminal you are about to use. This was a 7mm post terminal intended for 25mm2 cable. Test-aligning a 35 mm2 die showed that it wasn't likely to compress the fitting much and the 25 gave a better looking gap and so should compress well.
  

  

  35mm die surrounds terminal- little compression is obtained when the die is closed 

  
  

  

  25mm die still has room to compress

  I therefore inserted the cable into the post terminal...
  
  
  And crimped well using the 25mm die pair
  
  I slipped on the heat shrink and cable terminal cover, shrinking the tube
  
  
  
  
  
  
  I then crimped a 25 sized butt join connector onto the other end. This is a thin walled terminal and the 25mm2 dies seemed too small for this application. I therefore used a 16
  

  

    25mm cable butt connector crimped onto the other end using a 16mm die.
  
  

  This is where I got yet more evidence that the 35mm2 cable supplied was actually 25 since the cable in the car was larger- it was too large to fit into the terminal unless pre-crimped. I squeezed it with a 10mm die to neaten the ends.
  
  
  

  
  

  

  
  ...and it then fitted nicely. I used a 25mm die to take the larger cable into account. The join was then...
  

  

  Butt joint- 16mm crimp to new cable (upper) and 25mm to existing (lower)

  ... covered in heat shrink...
  

  

  ..to make a neat butt join.
  

  

  
  I could then refit the battery case- its a better fit now that the cable has enough length to bend naturally onto the terminal without lifting the carpet or displacing the battery cover.
  
  Overall its now my view that crimping is difficult to get right and confusion in cable sizing is largely to blame. This is probably why there are a lot of soldered and bolted terminals out there. I am not happy that I have ended up with a smaller diameter cable connecting to the battery and I will probably change that later. For the moment I'm going to stick with it as a week spent buying wrong cables and connectors is too unpleasant to repeat just yet. It seems to me that the US system of marking and matching terminals to cables using  AWG could remove much confusion. It would also help if UK cables were similarly embossed with their CSA.
  
  Chassis Connection.
  The chassis connection is made at the rear underneath the car. The cable penetrates the body, exiting the boot at the front and there are a number of grommets and sheaths to prevent it chafing. It terminates in an eyelet bolted on to the chassis. This seems an obvious place to corrode and I'd like to check and clean the contact under the car. This attachment is apparently accessible via the rear right-hand wheel arch.  I don't know what mine is like because I haven't found it yet! I will need to raise the car to get at this connection so I'll leave the underside work until I can drive the car up onto ramps and tackle the exhaust at the same time.
  

  
  

  ... on a different tack...
  I will just note two unrelated observations that emerged from my considerable time spent in the boot. These will need tackling in due course.
  
  Firstly, the wiring loom crosses the boot and passes through the carpet at the top right above the battery. It then crosses above the battery to connect with the rear light. However there seems no way to fasten it securely to the top of the boot as it passes over the battery and the self adhesive clips used previously have long failed. I'm having to hold it out of the way in the picture above. This means it looks anything but neat! I'm not sure what would be best to hold it up out of the way and out of sight but I will see what I can find. Sadly as this is the outer skin of the car I can't use a screw fastening.
  

  

  Wiring loom passing above battery. Old failed adhesive clips present

  Secondly,  I found that there is a very brittle tube that seems to run around the boot and dives under the carpet on the the RHS. In my case this is not (or no longer) connected to anything and its somewhat mysterious. I did identify this and describe it here.
  
  

  

  Brittle plastic tube underneath carpet on RHS- apparently dipping down to leave boot at rear right corner.