Batteries

I had purchased some older but NEW batteries to increase the size of my initial pack. I now have 60 cells to put into my pack for 192 volt nominal system. It had been stated that the new old stock of the CALB SE cells actually had a small degradation of capacity just by sitting on the shelf at half charge. Out of 33 cells I found one that was at 270mv and would be considered by any other type of battery totally DEAD. Well not so with the LiFePO4 cells. I decided to do a slow charge to bring it back up to a level I could charge it with my PowerLab 8 charger. I did at 25 amps up to 3.6 volts and using a cc/cv algorithm which is standard for LiFePO4 cells. I then set it up to my discharge station and discharged the cell at 90 amps until it reached 2.6 volts. At which point it provided me with a total of 107 amp hours out of the cell. That is actually consistent with NEW cells right from the factory. I will test a couple more that were sitting normally at about 1/2 full to see what they give and to see if that makes any difference.

Pete :)

Inverter progress (soldering)

Well, today I finally made an attempt to solder a single driver board. The PCB is a through hole design to make soldering easier. On the back side you will find your solder pads around the holes. Some are large oval in shape and some just tiny round things. Those large oval shaped pads are much easier to solder than the other tiny round thingies. I screwed up and can officially say my soldering techniques just suck. My iron is a 20w iron but heats up to 860F and is a great fit for my hands. I like the tiny size and ease of use. I tried to fix a couple cold solder joints only to have them screw up again. Not one of the oval pad joints went bad. Only those tiny little round types. I re-cleaned the area and shaft of the component to be soldered only to find it ball up on the shaft. I am thinking that there is no more solder on the pad. That would make for a hell of a time getting solder to stick to plastic. It sticks to the shaft just fine. Now how to figure out how to get more solder onto the pad so I can try yet again.

The technique if soldering is simple. I use narrow gauge rosin core solder and a fine point iron and heat the pad and post and then put solder on the opposing side to allow solder to flow into and onto the pad and post.

I keep the tip clean and tidy and tin as needed. I don't have solder removal wire but will be getting some today.

Any ideas and tips would be helpful.


Pete :)

E Roadster

The roadster is up and running. There is still plenty to do on this project but I am now able to enjoy the ride.

  

E-Roadster Driving

Today, May 1st is the day I finally got the E-Roadster operational and driving. Shifting still has some issues that need to be addressed. It does drive. Pics. It got a bath today. Wanted to mount my hubs but can't find my duz fittings. So when I find them they will be mounted. It should look better with them on.


Pete :)