DIY Electric Car Forums banner

1 - 5 of 5 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
Well I did a second drive today. We have balanced our pack of 32 100 AH cells to a reasonable level. We are not charging our pack very high at this time. We are using a Quickcharge Select-A-Charge 96 volt charger. It should charge to 122 volts but is not going past 114. Mmmmmm. Oh well its keeping our pack in a very safe zone. I changed my battery amp limit back to 250 instead of 400 which I had it set at in our first run. Our first run netted us 19 miles and our run today was 12. Having our controller set to 400 battery amps allows for a spritely run but was hard on the little 100 AH cells. We did have two cells that were low and they did heat up quite a bit. Today we did not have that problem now that our pack is reasonably balanced. All our cells discharged well. The stayed cool and so did the motor and controller. I am going to bring up the limit to 300 battery amps.

So, we have a nice little all electric car with lithiums and a nice controller and motor. It runs well and will provide a nice little electric runabout for someone. Plenty of room to add more batteries up front.

I will be posting a quickie 4 minute video on youtube of the drive once youtube comes back up for posting.

I am pleased with our little project.

Pete :)
 

·
Registered
Joined
·
148 Posts
Congats on getting Midge back on the road. Looking forward to more results as you get the bugs worked out. Are you planning to get her weighed when you're finished?

Your 'Garage' info states you have 34 cells, but your first post says 32; is one of these a typo?

Unfortunately, I haven't made any progress on my conversion as my shop isn't heated and we're just starting to get up to "melting". Last week we barely made it to double digit temps.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #3
Well yes sort of. I was originally going to do 38 cells but decided to use my Quickcharge charger so I had to recalculate the number of batteries I needed and that was changed to 34 which would charge each cell to 3.6 volts. While I was writing for some reason I had 32 in my head. Guess I forgot to fix that one. I have 34 cells which should get me up to 3.6 volts per cell. The charger is not working properly and I am only getting up to a total pack voltage of 114 at the end of the charge. They settle in at just around 3.29 to 3.26 volts per cell. I have an email out to Quickcharge about this issue. It looks like the charger works fine up to the point where it is supposed to allow the voltage to finish. It may actually be working just fine but because of the way lithiums charge it may still not be full enough to get to that point where the final charge voltage is at 122.6 volts or 3.6 volts per cell.

Lithiums are odd creatures but so far I really like them.

Pete :)
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #5 (Edited)
Another two drives today. Culled out 4 batteries and put in 4 others. It is now a better matched pack but at the top end I still have a few that go high quicker than the others. I am going to bring up some low cells for our next drive. I was able to charge the pack for a full 5 hours at 12 amps until two batteries came up to the knee. I shut down there and the pack voltage was 119 volts. They can still hold more once I flatten it out more and still be in the safe zone. I should be able to stuff in 122 volts to this pack and be safe. I have 34 100AH cells. So at 119 volts I am sitting at 3.5 volts per cell when I shut off the charger. My last run was a solid 17 miles at 55 mph pulling 200 battery amps average during the drive. So at 200 battery amps and at some points a bit lower I was able to do a decent drive with such a small pack. I bumped up my battery amp limit to 500 this time and loved the acceleration. Not mind boggling but nice. This will make someone a nice first EV for some good around the town driving and some freeway driving.

This is also in temps below 40 outside. :)

Pete :)
 
1 - 5 of 5 Posts
Top