Our Stay in Guatemala City

Today we were not schedule to drive anywhere, and had planned with the university to deliver a presentation to a large crowd of students and journalists, with the British Consul coming along as well. And so, at 10am, we arrived at the event where the car was all clean after the night before, and was standing prominently on a stage overlooking the audience. After some introductory speeches from the university’s Rector as well as members from the British Consul, we were invited up on stage to present the car and project.

Andy and Toby did an excellent job, with Toby presenting in Spanish, and Andy having his words translated. The audience was incredibly attentive, and once the presentation was finished, they were invited to ask any questions. Once again, the level of interest in the project and electric cars in general overwhelmed us, and it shows that even in poorer and less developed parts of the world, EVs can play a vital role in reducing the country’s expenditure of fossil fuel imports, a vital step in keeping money within a country.

After the Q&A session, the audience was invited to come up to the car, meet the rest of the team, take photos, and to ask any further questions they may have. We took of the rear bodywork for everyone to see what physically drives an electric car, and the reaction was very positive. The net lasted until around 2pm at which time most people had trickled away, and there was only ourselves and our hosts left.

During the event, we had our first experience of true Guatemalan rain; it was really a sight to see! For 3 hours torrential rain lashed at the marquee, and as we saw in Mexico City, the roads turned into rivers. It was a sustained attack from the heavens! With this in mind, we decided that even more waterproofing on the car would certainly not be a bad thing, and so Nik and Toby went with Roger, one of our student hosts, to the local hardware store to stock up on various equipment to make the car more resistant to such heavy rain.

However, upon trying to start up the car to move it to a different place to work on it, they found that the car wouldn’t start. This was very strange as even that morning the car was working perfectly, and we could come up with no logical explanation. We took out the seat to have a look at the high voltage electronics and control boxes underneath, but there were no problems here, so the investigation proceeded at the rear of the car, and this is where the problem was found.

Way back in March when we were assembling the battery pack, we inserted thermistors, essentially temperature probes, in several places throughout the battery pack. This was to monitor battery cell temperatures to ensure that they never get too hot. Experience soon taught us that no matter what we did with the batteries, they would never really get beyond luke warm, and so even though our control system was monitoring them constantly, we never paid that much attention to them.

However, on inspecting the rear battery pack, Toby found that one of them had broken, and he suspected that because it was broken, it was giving an error reading and actually telling the car that the batteries were at 100 degrees celsius. So, in order to alleviate the problem, we opted for changing the software rather than the thermistor as we had found that they were pretty useless in the functioning of the car, even when it was 45 degrees celsius outside. So in essence, Toby told the car’s computer to ignore the temperature readings, and from then on the car worked fine. This was the first software based problem we had encountered on the trip, and we were pleased to have solved it so quickly.

With the car back to working condition again, we went out into the city with our Guatemalan hosts to have a great dinner and to sample a bit of the Saturday nightlife. It was fantastic fun, and even though we didn’t want to, we called it an early night and headed back to the hotel in lieu for an early morning start the next day.

Many thanks to Francisco, Roger, George, Cindy and all the others from UMG for giving us such a great time Guatemala City!

One Response to “Our Stay in Guatemala City”

  • Charles H Schulmann says:

    Dear RGET ,
    hopefully that thermistor which “ broke ” will be replaced
    and the program will be restored to include the monitoring
    of the battery temperatures – please do not forget
    “ Houston we have a problem ” where information played a
    large role in saving Apollo 13 .
    The constant discharge and recharge often unconventional
    still have to prove that the battery pack will stand the
    test of time .
    Did the thermistor break due to mechanical vibration or
    was it electrical are questions which should be investigated
    to see if the cause could have an influence on other parts
    of the circuit and not dismissed so lightly – yes granted
    the diagnosis and subsequent quick fix is commendable and
    necessary when the occasion arises , but may not be
    permanent !
    Remember the chargers and dampers which failed as they were
    subject to fatigue , are other components both electrical
    and mechanical prone to the same fate ?

    We wish you all our fondest admiration from Ladysmith
    ( Kwazulu Natal ) in sunny South Africa , Charles and friends .

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