216: Friday 25th November 2011
Several things to report from the last couple of weeks; I have now secured a swap deal with the battery recyclers for 23 lead acid batteries just like the ones I have already. This is especially good as they will swap directly and no modifications required except to put my charger back to work with 10 batteries again. I have been assured that these ones have been tested using a load and they are all holding 12v. The previous set were discharged down to zero volts and I had to recover them. I have some funding that I could have used to get Lithium batteries, but I could only get 100Ah. Now although this would give me more range than I have had so far, it would not be my goal. Since I now have a stock of 13 spare batteries coming as well as the 10 on the car, I can keep sparkie going for a long time with a limited range. I am hoping for about 20 miles or more this time. This takes care of most of my journeys. For me to say my car is in a finished state with respect to batteries, I would need to get 200Ah Lithium, that should give me a range of around 100 miles and for that I need to save some more money. It will come in time and sparkie will be complete. I have also got my wife to agree to let me get her another Jeep Cherokee and convert it to electric. We had one and she loved it, but it was just too expensive to run at 13 miles per gallon on a good day. The objective for me is to buy and convert for under £1000. I have some batteries I can use now and the car could take the weight of 20 batteries when I get some Lithium for sparkie. I am looking at the revolt 1000A controller and a salvaged motor from a Fork Lift truck. I am not sure about the charger yet. I believe the revolt will set me back about £500 and this is less than half what I paid for my Zapi controller and meters out more current too. I like the idea of open source code for the controller, so I can tie in a battery monitoring and display system. I also got my "electric" badges that I ordered from cloud electric in USA via Tim, cheers Tim! See photo below. I got 2 because I thought I would damage one removing it before I sent it off for a paint job, however I have decided to stick it on the plastic reflector between the rear lights, so it can just stay on. So I shall have a spare if anybody is interested for a modest price. I am supposed to be getting some made up by rapid prototyping at work in the original Ford Probe writing style, but I have not heard anything yet. Tomorrow I shall unload all the batteries to the front of the garage so they are ready for collection and I have space to receive the next lot. On Monday I shall call the recyclers to arrange the drop off and swap back and hopefully by next weekend I shall be up and running again. 
215: Saturday 12th November 2011
Yesterday I set about changing the output voltages for the Zivan charger. I wanted to try to operate on 8 batteries instead of 10. Since I melted that last battery I have tried to find some batteries good enough to use as dummies just to get a charge into the car. I had been charging with ten and running the drive on 9 batteries. I have a reasonable set of 8 batteries and this is enough to drive my car (just). In the photo below you can see 2 of the screws that need to be removed to take the case off the charger.
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The next photo shows the other 2 screws at the other end, then the case comes off, but you do have to prize the mains cable out of the case as the rubber grommet sits in a slot that goes round a corner on the case. I have circled the screws in green. When removing the case take care not to knock the indicator LED and the selector switch for the different charge curves. The selector switch has a screwdriver adapter pushed on it and it pops off quite easily. If you disturb the LED then it may not line up with the window in the case when you put the case back.
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I connected the charger to the mains and measured the output at the small Anderson connector and found that it starts at 143.8v for a few seconds then changes to 136.5v as the indicator goes from red to yellow to green flashing. As I have 10 batteries that makes 14.38 volts and 13.65 volts per battery on average. If I multiply these by 8 then I know what the new voltages should be. I calculated them as 115.04 volts initially, then settling to 109.2 volts when the indicator is green flashing. The photo below shows the logic board sticking out of the main board. I have outlined it in green. There is a voltage and current adjustment multi-turn potentiometer on this board. Take extreme care not to touch the heat sinks as some of them will hold a high voltage and give you a shock.
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In absolutely tiny writing on the board you can just make out the letters "I" and "v" beside the two potentiometers. The right hand one in the photo was adjusted, but the voltage would not go low enough.
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On the main board by the Anderson connector is a resistor labelled "R20". I soldered the equivalent of 2Mohms resistor across this resistor. I turned the power off first! When I powered up and allowed it to settle, the voltage was too low, so using the voltage adjustment pot again I wound it up to exactly 109.2 volts. When I cycled the power off and on again the initial voltage was 115.1 and then it settled to 109.2 volts. This was exactly what I wanted, so after breakfast today I fitted it back on the car. In the photo below I have put a plastic clamp between the crocodile clips on my tester just to stop them touching together.
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In this photo you can see the tester showing the final voltage after I had completed the adjustments. Unfortunately, despite my efforts, the charger was then stuck in a reset cycle as it was still seeing a high resistance load from the batteries, so it was continuously starting and resetting. I shall try rotating some batteries round again to see if I can get it to charge properly. I had this problem before I started and since I spoke to the supplier on the phone they confirmed it is caused by a high resistance in the battery pack.
The next photo shows the other 2 screws at the other end, then the case comes off, but you do have to prize the mains cable out of the case as the rubber grommet sits in a slot that goes round a corner on the case. I have circled the screws in green. When removing the case take care not to knock the indicator LED and the selector switch for the different charge curves. The selector switch has a screwdriver adapter pushed on it and it pops off quite easily. If you disturb the LED then it may not line up with the window in the case when you put the case back.
I connected the charger to the mains and measured the output at the small Anderson connector and found that it starts at 143.8v for a few seconds then changes to 136.5v as the indicator goes from red to yellow to green flashing. As I have 10 batteries that makes 14.38 volts and 13.65 volts per battery on average. If I multiply these by 8 then I know what the new voltages should be. I calculated them as 115.04 volts initially, then settling to 109.2 volts when the indicator is green flashing. The photo below shows the logic board sticking out of the main board. I have outlined it in green. There is a voltage and current adjustment multi-turn potentiometer on this board. Take extreme care not to touch the heat sinks as some of them will hold a high voltage and give you a shock.
In absolutely tiny writing on the board you can just make out the letters "I" and "v" beside the two potentiometers. The right hand one in the photo was adjusted, but the voltage would not go low enough.
On the main board by the Anderson connector is a resistor labelled "R20". I soldered the equivalent of 2Mohms resistor across this resistor. I turned the power off first! When I powered up and allowed it to settle, the voltage was too low, so using the voltage adjustment pot again I wound it up to exactly 109.2 volts. When I cycled the power off and on again the initial voltage was 115.1 and then it settled to 109.2 volts. This was exactly what I wanted, so after breakfast today I fitted it back on the car. In the photo below I have put a plastic clamp between the crocodile clips on my tester just to stop them touching together.
In this photo you can see the tester showing the final voltage after I had completed the adjustments. Unfortunately, despite my efforts, the charger was then stuck in a reset cycle as it was still seeing a high resistance load from the batteries, so it was continuously starting and resetting. I shall try rotating some batteries round again to see if I can get it to charge properly. I had this problem before I started and since I spoke to the supplier on the phone they confirmed it is caused by a high resistance in the battery pack.
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The next problem is that the new lower voltages mean that the contactors are not in the correct voltage range as they are meant to be 120v, but now operating at 96v. I was getting a problem with the reverse contactor not releasing some times. I am concerned now that this will be too much of a stretch to try and run like this. I desperately need some more batteries. I shall persevere and see how it goes.
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