Synkromotive Controller

Well progress is being made with new testing of the new production model of the Synkromotive controller. Ives from Synkro is doing some high power testing and the controller is living with no trouble under this power. He has upped the minimum amperage to 800 instead of 700 and has even tested it with 900 amps with no ill effects and the fan is keeping the processor and internal components quite cool. This is excellent news. There is more to come with the controller.

New Midget

Well, I now have a 120 volt system of 38 100AH Hi-Power Cells installed and running. I now have our large 3000 Elcon charging the pack. Our last outing we lost our brakes. The master cylinder is toast. I also have a clunking sound when doing right turns. We need replacement parts badly. I found another donor vehicle to use. I will either use the new one or use the new one for parts. The new one is red and original color and not a repaint over blue like the Black Midge. The new one has all it's parts including the top and tonneau cover. The chrome parts look to be in better condition too. Has current pink as well. I am thinking of using this one for our donor and selling the other with the engine and fuel tank from the new one. That way I can get some money back. The Black Midge is still a good vehicle but the red one may prove to be better. Maybe. I go to pick it up this morning.

Driving Time

Been driving my MG now almost every day since I balanced the cells and got the Elcon charger up and running. I am getting about 6 hours charge times and 20 miles at a decent speed. In town speeds will net further distances if I coast between stops and try to hypermile a bit. The car keeps up with traffic just fine in town and on the Hwy I try to stay at about 55 mph. My batteries are only rated at 1C so when I am above 45 my amp draw from the batteries is up around 175/180 at 55. If I push for more speed it goes up even more into the 220 amp range. This is hard on these batteries and the batteries are warm at the end of the run. So a recap, Impulse 9 motor, Synkromotive controller, 30 100AH Hi-Power LiPoFe4 Cells, and the rest of your normal stuff. The system voltage is rated at 96 Nominal if I use 3.2 volts per cell as my nominal voltage. If I were to use 3 volts per cell I would need two more cells. I am going to try that. I need to see if the charger will still get to the required end voltage before termination with the extra batteries. It should and leave the cell voltage at a good 80% of normal. Once my current pack is charged, 109.5 volts when it goes into CV until the amps are zero. That last 10% goes so fast it is almost not required. My resting voltage after an evening is 100 volts. When I had my 96 volt Lead Acid pack the resting voltage after an evening was 102 volts. If left longer the voltage was 98. The DC DC is always on but never powering any component. The only component that really draws any current is the volt meter. Interesting. Went to have another check. Yup. 98/99 volts. My controller reads 99 volts. Checked to see if there was any voltage leakage. None. So my cells at full rest and full charge sit at 98/99 volts.

Charging Time

The 30 cells spent the night and all day in parallel and all had the same starting standing voltage of 3.12 cells. This is after sitting for a couple days after discharge. Cells would bounce back to this resting voltage. Charger has been on for 3 hours and 12 minutes now and doing fine. I thought a cell was going to jump but it did not and is once again settled in with the rest. So far all the cells are well balanced. I will be shutting down until tomorrow and will resume tomorrow until the pack is charged. So far so good. Nice little elcon charger. Set for 3.6 volts or so from what I was told. We shall see.

Pete :)

all the piggies in a row

Well I now have 31 cells discharged to 2.4 volts or there abouts. I put all 31 in parallel tonight and began discharging more. What I found was that the cells would get hot on the negative side post but the whole cell as a unit did not get hot. But because the post got hot that means that the post on the inside got hot as well. At a discharge rate of 50 amps or more I found that some cells would puff a tad. That to me indicates that part of the cell pack on the inside was getting hot enough to gas off a bit that is close to the terminal causing a slight bulging. The cells are rated for 1C discharge but that rate does cause the negative terminal to get hot and I think hot enough internally to gas some near the post. The rest of the cell remains cool. As does the positive terminal. That is an interesting find. Some of the heating issues may be due to some minor corrosion. Both the pos and neg terminals on the Hi-Power are aluminum and that will oxidate easy. So I think I am going to use a very fine file and clean off all the terminals where the connection is at. That may help some.

Will be charging the first pack tomorrow. My charger is set to 3.6 volts per cell. According to what I have been told. We shall monitor the entire charge cycle from start to finish and we may need two days because I must work and won't have time to watch the whole process in one evening, maybe.

Pete :)

I am now discharging at 50 amps slower but cooler and easier on the cells.

Hi-Power Balancing Act

Well, I am currently taking all my extra Hi-Power Cells and discharging them to 2.4 @ 90amp draw. Once I get to that point I terminate the discharge. I have a batch to charge up a bit then discharge them to 2.4 @ 90amp draw. I prefer to terminate at discharge than charge. I set up two motors in parallel and get a good solid 90amp draw during the entire discharge. Time for each cell so far today has been just over an hour. The cells are 100 AH cells so my capacity so far is good. I did connect 4 cells together and ran them in series but two cells were not balanced and I heated up two of them to the point of bloating. They still hold a charge and I did check for internal gas and they did gas. I released the gas and squeezed the cells back together and let them cool. I did discharge one to zero volts but after sitting it is just under 1 volt. I am going to charge then discharge them to see how long it takes to check my capacity. So far all my capacities have been at least 1 hour when I discharge a single cell at a time. Yes I am running two 9" motors in parallel with a single cell @90 amps. The GE motor runs much better at low voltage than the Warp9. Both are still running at the end of discharge but the Warp9 is very very slow. So my video of the Hi-Power cells is wrong and I will be removing it from the archives. I did find gas and it is possible to squeeze the cells back to normal if you do it while the cells are still soft and pliable. I am doing one cell at a time and it is going to take awhile. I am going to redo the ones in my MG because it looks like a few may still be out of whack just a tad. So I will drive the car. So far I am finding that 2.8 volts should be the absolute final voltage to take these kind of cells. That is pretty much it. They give a bit of extra to limp home but it is not advised to drive them much or very hard beyond 2.8. The controller should shut off at 2.6. So my top charge will be 3.6 and my end will be 2.8. Shut off at 2.6. No exceptions. Now its time to get some better batteries.