After talking to some people, it became apparent that I was just being slack with my soldering job on the battery system :
Even I wasn't too happy with it at the time, but figured it might be good enough. However, there's no point going to all this trouble if we're going to leave a dodgy, unsafe join like that right in the heart of things. Better to fix it up, do it right, and never need to worry about it again.
That was as good as I could do with my 40W soldering iron - I just couldn't get enough heat into the huge wires. So yesterday I called into Jaycar, and picked up a new 80W unit.
That's it on top. It's a massive iron - the tip is around the same size as a pencil, with a huge slash-cut end. Plus (more importantly) it's got the power to back it up!
First order of business was to dismantle the back of the car again, and remove all the insulation tape from the previous join.
Surprisingly, it didn't look any better than it did the other day. Still pretty rough! Once it was all clean, it was time to hit it with the big iron and a bunch more solder. Unfortunately the biggest solder Jaycar stock is 1mm diameter stuff. So we used almost an entire container of it here!
From this:
To this:
Much nicer! You can see how the solder has all melted and flowed into the joint, instead of just clustering about on top.
You can also see how the exposed wire has all been tinned by the solder, and gone from the gold/copper colour of the bare wire to the dull silver of the tin in the solder. Not only will this make the joint nice and solid, it will server to protect it from corrosion should any moisture managed to get in through all the electrical tape.
That's how it should have been done from the start! The join is now super strong, and will last a lifetime.
Once everything had cooled back down, we re-wrapped both wires with at least 3 layers of electrical tape to re-insulate them. I couldn't use heat-shrink here, as I had no way of getting it over the wire. I experimented with a large piece of heatshrink wrapped around the wire a couple of times, zip-tied on and then heated, but it simply unfurled itself as it shrunk, and provided no benefit whatsoever. So electrical tape it is!
Once the individual wires were wrapped, we wrapped the entire join in black electrical tape, and added a couple of cable ties to give some mechanical support.
And I hope never to have to cut that all apart again!
While we had the back of the car apart, we decided to fix one of the shortcuts we'd taken previously. We have a volt-meter fitted into the back panel, with a 3-way switch to change it between MAIN - off - AUX. Previously we had only wired in the AUX connection to it, and the connection to the MAIN battery was put into the too-hard basket. But I really wanted to be able to monitor both batteries when the controller had disconnected the two (of course, when they're connected together, it doesn't matter which one you select - you get them both at once).
A little probing around the back of the car found a const 12v hot wire going into a control box of some sort (Relay maybe? If so, for what? Rear Wiper maybe?) on the opposite side of the car. Disconnecting the batteries, I cut that wire, and joined in a small-gauge wire and ran it across the back of the car under the carpet, twisted around another wire that ran the opposite way for my towbar connection. Once over to the driver's side of the car, it was an easy enough job to route it behind the control panel and joined it up to the switch.
So now I can switch the volt meter between the MAIN battery:
Off (to save power when I'm not looking at the meter, not that a meter will draw much power anyway) :
And the new AUX battery:
You can see here that the controller had isolated the MAIN from the AUX, which is why the readings are different. If I were to go out now and check, the controller will have both batteries connected, and the reading will be the same regardless of which position the switch is in. Happy with that!
Finishing off some of the other little jobs, I trimmed down the positive terminal cover on the battery. I could have just left it off altogether, but it's a good, cheap, effective safety measure to have it on. But with the new power connection squeezed onto the terminal, it was too tight a squeeze. 5 mins with a hacksaw blade and a file, and voila:
Just like a bought one!
The front panel is all in and connected:
And working well. Can you spot the potential problem, though?
Here's a hint.
The top of the MAIN fuse block is at about exactly the same level as the bottom of the inside of the bonnet - you can see in that shot that the front corner of the clear cover is ever so slightly above the level of the guard panel lip just past it. The wires are fine - they've got extra insulation zip-tied onto them wherever they touch metal, and just squish down. But that hard-plastic cover might be a problem.
It's not currently being used for anything - it's just there for future expansion should I want to run any accessories off the MAIN or AUX batteries under the bonnet (think spotlights, etc). So if it breaks after 6 months, we'll re-think the design and fix it then. For now though, I'm happy enough just to leave it be and see how it goes. It might be fine - I don't know.
So finally, it's all getting close to being done.
Only a few more tidy up things to do - trim the inner guard lining and re-fit it to the rear passenger side, trim the front inner guard linings that we removed when we fitted the bar and put them back on. Wrap some of the exposed cable in split-tubing and zip-tie it all securely out of the way (both in the engine bay, as well as under the dash inside). And some other misc bits and pieces. But we'll get to them over the next few weeks!
Oh, and Jess is threatening to go down this weekend and buy the fridge we want, now that the electrics are all done! :)
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