174: Wednesday 19th January 2011

Yesterday I took the Probatron for its first dip test. This was not intentional, but I am glad it happened so now I know what happens when the motor and controller etc. get covered with water. I was giving my daughter a lift to the local college where she was doing some football training and as I approached the entrance from the roundabout I did not notice that the junction was completely flooded. As I went through the flood, a bow wave came over the hood and I kept it going to get through and out the other side. I only got a few yards before the controls all died. My daughter walked the last few yards and I put on my hazard lights and called the rescue service (RAC). I waited about 10 minutes then tried the main start and it came on, but the contactors were cycling and that means that the controller was detecting short circuits. This was a good sign as the controller was working. I could see the 1000A fuse was still intact, so this was also a good sign. The programmer was working, and showing the voltage and current levels, so that was another good indicator. I had my daughters phone as I had left mine at home on charge and after a few minutes it was locked out on a password. My wife had called me back to tell me that the rescue service said they would be about 40 minutes getting to me, so I knew I could take incoming calls. I tried it again about 20 minutes later and I got a bit of forward drive before it cut out. This at least allowed me to get over to the edge of the road. Another 5 minutes and I tried again, and this time I could keep driving, so I drove round to the college sports hall entrance so I could get the password for my daughters phone. At this time I had no reverse gear. When I set out I did not have much charge and this swim had eaten a bit more from the batteries. The rescue van came and we disconnected the batteries at the Anderson connector and dabbed the contactors etc. with tissue paper to take up the water laying on top. I still didn't have reverse, but we decided to give it a try to drive home. my daughter already had a lift home arranged, so that was no problem. I got half way up a steep hill and ran out of battery power. The rescue man towed me to the top of the hill and from there it was all downhill. So with gravity on my side and the small charge that had re-established I drove home. There was another slight rise in the road that got me down to 15MPH, but I got home, still no reverse and we pushed it backwards up the drive and plugged in. Had quite a nice chat with the rescue man and then just left it on charge. The next day I came out to a dry car and everything worked fine again. So endeth the dip test. I believe that if I got the speed right then I could have got through the flooded area without much issue, it was mainly the water getting into the electronics on the controller that stopped the drive. As the controller is mounted on top under the hood, I just need to prevent water getting up that high. Hitting a flooded area at speed is not the right approach either! Another mini adventure over.

173: Saturday 8th January 2011

Nothing much to report at the moment. Had a reasonably uneventful Christmas with the Probatron. My range has reduced now to a mere 15 miles. I am worried that I have damaged my batteries with a few journeys when I ran them down too low. I am not sure the Lucas batteries are up to the job either, but without hugely heavy traction batteries, I believe the only really well proven batteries are the Trojans. I could have bought these, but it was the maintenance that I wanted to avoid. This could be an expensive mistake. This has made me start researching places where I can get Lithium Iron Phosphate batteries cheap or to find the funding for the prices as they are. This will increase my range too. I currently have batteries rated to 18kWh and this should get me about 50 miles. Lead acid batteries are only good down to 20% DOD and that is about 11.6 volts on each battery, so then at 350Wh/mile I should get 40 miles. Now this is in ideal conditions. I have achieved this figure a few times, but not recently. With a Lithium pack I want 36kWh and I should be able to use all of this and get around 100 miles from a single charge. I am now keeping a log of every journey to include the start and finish pack voltages, the start and finish distances, when a charge is made, the driving conditions, the extra equipment I had running, such as lights and heater etc and what modes of operation were being used such as sport and economy mode, which gears etc. My first data collection saw a distance of 15 miles, but some of this was using the heater and lights. I am lucky to get 20 miles lately. maybe this will improve as the weather improves. I understand that the batteries cannot accept as much charge when they are cold. Invariably they are being charged then left cold for another 5 hours or so before being used, so this does not help either. This does limit the journeys I can do, but I can still get to work o.k. I will be working on a garage tidy up soon. I am just finishing off the floor tiling in my kitchen then the garage is next. So then I shall get the rest of the displays up and running. I have had some bother getting an electronics supplier to send me the right connector for my matrix display, then I can start my experiments to get that working. That should keep me busy for a while.