156: Monday 31st August 2010

I have now had the new batteries installed for just over one week and I have had almost no issues. The racks were about an inch too wide and as a result of this, the batteries shift when I go round a corner and this is stressing the hold down brackets. This is easily cured by just pushing the batteries to one side, then packing the bracket out with a piece of wood to stop them from shifting. It is not doing any harm that I can see, but I guess in the long term something is likely to break or wear through, so I shall fix this soon. It is a bit disconcerting when heavy cornering and you get a bump as 400kg of batteries suddenly shift to one side. I shall have to slow down a bit on corners until I have them packed out. The problem with the racks is that they were made using the measurements given by the manufacturer of the batteries and the reality is a few millimeters different, and when you have several batteries in a string, you get the accuracy exaggerated. This is why the racks were too short and too wide. Next time I shall fit the rack to the batteries exactly by laying the whole lot out beforehand. Anyway, some good news, I have achieved 30 miles on a single charge for the first time. I expect this figure will go up in the next few weeks as the batteries become further conditioned and depending on the journeys I do. I am pleased also that this 30 miles was made up of several short, stop-start type journeys, some night driving with lights and after being left over night as well. So this is almost the worst case. I guess that will come with the winter cold and darkness. However, I shall always be able to get to work even if this is completely in the dark with the heater and lights on the whole time with plenty of battery to spare.

155: Sunday 22nd August 2010

I laid the rear battery bracket on the ground and tried 2 batteries in it to make sure they would fit. I had made the total length slightly too short so the handles on the batteries were clashing. I wasn't prepared to remodel the bracket, so a wooden block under one end of one of the batteries allowed the handle to overlap and get the distance I need. Making this change introduces other problems; the electrical connections were no longer lined up and the hold down brackets were too short. To resolve these issues, the copper straps were made with an angled step in them so they can connect at two different levels and I cut the bolts off the hold down bracket and welded new ones on the end with more thread available. This extra work added about an hour.
I applied the coat of customary red paint and set about making the copper link straps and cutting the hold down straps to the correct length and drilling them.
Unfortunately by extending the bolts for the hold down bracket, the new paint was damaged. I can touch this up another time as this bracket is accessible with all the batteries in the car.
With all the bits made, I mounted the rear battery bracket in the trunk, loaded the batteries and connected them. You can see in this photo that 2 batteries just about fit side-by-side in the trunk. There is only about 15mm of space right at the back.
As the batteries cover most of the floor of the trunk there was no way I could use the spare wheel well, so this has a new home just to the right of the batteries. I shall make a cover for the new battery layout as the terminals are exposed and I want to be able to use the remaining space for a bit of shopping or whatever. The alternative possibility for the future is to cut the floor out where the fuel tank was and mount the batteries there. I think I will wait until I can get Lithium Iron Sulphate batteries before I make that change.
So now with everything back together I went for a test drive. I was keeping a keen eye on the off-load voltage showing on the motor controller programming unit test function display. I took it down to 116v and had completed 22.5 miles. It still had a good pull even at that level. That's pretty good since the batteries had not been charged since new and judging by the boxes they came in, that was a while ago. Once I got past 15 miles I was smiling as that was my best distance for quite a long time with the old batteries before they started to deteriorate.

154: Saturday 21st August 2010

I had to make one more cut before I could assemble the base of the rear battery rack, but first I was out to the shops to buy some welding rods. I took the old hold down strap and cut it down to fit the width. I then welded the rack together and tried it in the trunk. It seems to fit well and did not need to be raised as the spare wheel cannot sit in it's well any more. I then measured up for an outrigger for the bottom left fixing point as the corner of the rack was in mid air above the spare wheel well.
In the photo below (taken from the side) you can see the outrigger added. I made this from angle iron and welded it in as many places as possible as it will be providing support and not just positioning the batteries. I drilled holes in the bracket at the top to fit the existing fixing from the last bracket, then fitted the bolts and drilled holes for the bottom end so I had marks to fit riv nuts to the body. I installed these then the whole bracket was secure.
The next step was to make the brackets for the hold downs to go across the top. I had given the last of my threaded stud to one of my neighbours so he could fit a chrome bull bar on the front of his van, so I had to shave the heads off four 8mm bolts and weld them to the brackets made from flat steel bar. In the photo below you can see the hold down brackets added. We were going to a torchlight parade in Southend so I had to pack up and get ready to go out. I could have used another hour just to get some paint on ready for tomorrow so I could go straight to fitting the batteries, but it was not to be. First job tomorrow painting, then to make up the 2 hold down straps.

153: Friday 20th August 2010

I fitted the battery hold down bracket and this went in easily without any further modification. I found the 12v charger wedged nicely under the slam panel and that was about where it was before. I then made up a link cable to join the batteries in series.
I then moved the DC-DC converter to several positions and found a bracket holding the 2 fan relays that are no longer used. I clamped this up on the bracket sticking out from the bottom of the DC-DC converter and now it is held in it's new position next to the suspension.
I then went to the back of the car and took out the old batteries and the rack and started making a new rack. When I was taking the batteries out I found the offending battery had a big bubble on the plastic at the back. A quick run over with my tester revealed a voltage of 10.3v and the others were all 12.3v, so the others may still be serviceable if anybody wants to buy them I have 9. I decided to change the layout again to improve the connections and keep them to copper straps and really short. I want to avoid making up cables as much as possible. There is much less to go wrong with a simple copper strap. So looking into the trunk the layout will be 2 rows of 4 batteries. For this I only need to make one link cable and the rest can be joined with copper straps. It also looks a lot neater. I got most of the metal cut, but ran out of welding rods, so I packed up for the night. Tomorrow I can finish cutting the pieces and welding them all together, then I can paint it. When the paint is dry I can install the bracket, load the batteries and connect them, then I should be mobile again.

152: Thursday 19th August 2010

Yesterday I spent most of my spare time putting the battery rack back in the front of the car and remounting all the other stuff that I had to remove to get it out. I put the 2 batteries in the rack and connected them. I had to make some stops on the bottom of the rack for the bottom battery to sit up against. For this I just cut off a small piece of angle iron, drilled and bolted it to the bottom of the battery rack. I took the old hold down bracket and cut it to modify it to the new batteries. This was much easier than starting a new bracket, so I had to make one part shorter and the other part longer to fit the new batteries that are wider than the old ones. Today I got to remaking the bracket to the correct size for the new batteries. I had some steel bar that I cut to extend the bracket, then welded it all back together. In the photo below you can see the modified bracket all freshly painted with fire engine red Hammerite. This is now ready to go back on when the paint is dry. I need to make a cable to link up the 2 batteries and remount the DC-DC converter and 12v battery charger as they were on top of the old batteries, then the front end is all done. My friend dropped off some more angle iron as well for the back end brackets, so I am all set to start on this tomorrow. I have an early finish at work tomorrow (P.O.E.T.S. day), so I should get a fair amount done and hopefully I will be back on the road some time over the weekend.

151: Tuesday 17th August 2010

Monday the new batteries arrived as planned. They are actually Lucas batteries and Numax is another brand name. I sort of knew this, but these are clearly marked Lucas. The spec is what I expected. They are 44kg each and that is about the same as the ones I am taking out. The dimensions are such that I can only get 2 in the front of the car and that means I need to put 8 in the trunk. This required a quick remodel of the layout on the PC, printed it off and set about refitting them. I didn't get much done yesterday as I was busy trying to bodge the batteries in, then having a hissy fit about the mess in the garage. Once I had calmed down I decided this is not the right approach as everything else so far has been done with consideration and very little bodging. I decided to just remove the front battery rack and cut it down to the right size for the new batteries.
You can see in the photo below that the bracket had to be adjusted about 80mm narrower to be able to sit the batteries on the rack. I used my angle grinder to remove the bracket, then I drilled a hole through the bracket parts and cleaned up all the ends with a file and finally bolted it together. Then into the garage for more of my spectacular welding :-). Now the bracket is sitting in my vice with a fresh coat of that fire engine red Hammerite paint on the exposed parts where I have made alterations.

150: Friday 13th August 2010

Last week the batteries gave out on the Probatron. I was driving along on a local journey, and after about 3 miles the batteries let out a scream, a sulphurous egg smell and I had a drastic loss of power causing the controller to reset. I guess this is what happens when a battery reverses. I have heard of this phenomenon, but never experienced it. Fortunately this happened when I was on my way back and I only had to go round a corner then park up. So now getting some new batteries has moved up the agenda somewhat. First I needed to find funding as I had already worked out what to get and where to get them from. I eventually figured out how to pay and made the order yesterday. I got a phone call today saying that the batteries had arrived at the depot and they will get them out to me on Monday. The batteries I have ordered are Numax SLC150-12 AGM lead acid batteries, 10 of. They are 12v each and 150Ah @ 20 hrs. I now need to rebuild the battery racks as these are different dimensions to the previous batteries.

149: Tuesday 3rd August 2010

Not much happening at the moment. I went to build the circuit for the current sensor and I looked at the data sheet and found that I need 3 capacitors and a regulated 5v supply. I had none of these parts, so I ordered them on-line today and they should arrive before Friday I ordered a 7805 voltage regulator as this is a fairly standard 5v regulator. I am on vacation at home at the moment and I am doing some building work on the back of my house, so progress on the Probatron is slow. I am also trying to figure out how to raise some money for a new set of Lead acid AGM batteries. I have some lined up from a supplier. They are Numax 150Ah AGM batteries and will cost around £1868 for 10 batteries. I prefer Lead acid AGM because they are relatively cheap, but the AGM construction is sealed and built for taking regular heavy loads and recharging. These are the best for their regen ability as "opportunity charging" is not a problem.