Awesome. Im going to clean up the battery configuration and add the BMS wire tonight. It was really a night and day difference with that extra battery!
Cant do that. T4 is different generation.’
Rodney
Start another thread about high voltage performance and keeping the coil cool while you’re testing.
Another weak spot is the heater. It heats really really well for 30 seconds. 
No issues reported with dc-dc converters.
I ran it hard for 2.5 miles yesterday and the coil was warm but not hot. Granted it is 45 degrees here and I had the dash apart so it was well ventilated. Im going to keep an eye on it while I keep testing. Maybe Ill get a harbor freight infrared thermometer today.
Good news is, at 95.9v start, I put 2.49 miles on the GPS, Averaged 23.2 mph Max 38.7mph and ended up with 94.8v, a drop of 1.1v.
How low can I take the lifepo4 cells? Im reading crazy numbers on endless sphere.
2.5v from specs. I only test to 3v as near dead at that point.
Did you say you had a bad cell? I can replace it if you do.
2014 should run at 100v with 15v spoof.
Thought I was on to something. The larger drop after settling 1 minute is an illusion.
The scale is different. Both settle from 3.5v charging to 3.25v almost immediately.
30s is doable in a Gem. 30x3.25v=97.5v
Top is a normal 67ah
Bottom is 2nd test of a questionable 63ah
I did have one battery go bad but that was #13 the last of the front string of cells. It was taking a beating and finally kicked the bucket. I transferred all cells under the rear seat and wired in the BMS this morning. 29 fits perfect, you could squeeze 31 if needed.
I’m going to clean up the wiring and I’ll post some pics in your new thread.
1 Like
Are you sure? 1v at battery?
Seems so as bad wire affects two cells.
Let me know when everything else is ok and I can send some replacements.
Got a minute to talk?
Call me when you can 516-524-1839
Got the resistors yesterday…No idea how to wire them in. Could you sketch something up for me?
Duh, that makes sense. I dont know why I had the idea stuck in my head that it needed to go on the main coil main lug. I guess I thought it was a 12v.
Anyway, send me two batteries and let me know what I owe you.
I need you to send me a dollar payment again to print a PP label.
It saves a lot of trouble and makes sure I send it to the right Chris. 
ps.
What do you suppose happened to the bad cells? Just sudden death?
1 is no surprise, but 2 has me worried. I’m not 100% sure I tested them all. Some 10 packs were only spot checked.
I’m testing them all now.
The one is no question, hooked up to the long cable heading from front to back of the car. With all batteries in the back, that battery would have been #2. That battery was replaced by the spare which is charging to 3.29v.
The second one to go bad (which is battery #3 now) will charge to 3.20v while the rest after equalizing settle to 3.30v. While testing that cell held for about 1/4 mile before it fell off to below 1v.
The second one may just be low and need to be brought up to full matching the others.
The voltage doesn’t show the soc with lifepo4. All can be near the same voltage, yet be different % full.
No matter. I’ll send a couple out. Who knows, you might go to 30s.
How would you suggest doing that?
I am also running my chargery charger in power supply mode at 95.9v 15a. Would that make a difference?
That depends on what you have to work with.
The bms makes it hard to swap cells. Maybe disconnect bms.
Bypass the suspect battery. Run the other 28 down to the level of the low one. Then charge them all together. Keeping an eye on the odd one. Disconnect it again if it gets up to 3.6v or so.
May be the same with the first one. Unlike lead, lithium can’t self balance.
I could also send a single cell charger to bring low one up. That might be easier.
Once they are all in step, they should stay that way.
Balance is not important, only that none go too low or too high.
A cell that is 1ah lower capacity will always be the first to go high or low. Makes no difference, as pack is only the size of the smallest cell.
I have found it a fools errand to try balance on both ends.
I have this, it will charge LifePo4. Ill see if I can bring it up to the others.
https://www.skyrc.com/iMAX_B6AC_V2_Charger
How about the charger? Is that ok running it in power supply mode as opposed to Life?
