[mizlplix]

Truthfully, This is my third EV. The other two were FLA battery powered.
I am VERY experienced in their installation, maintenance and upkeep as well as their little quirks-strengths and weaknesses.

If you really looked closely, my car was set up for 20-6VDC GC sized batteries.
It would have been OK with them. I would have been OK with them.

As with so much on the internet, I read and re-read so much about lithium batteries that it made my head spin. So much contradictory information. Lots of it was by persons never having owned any....Just what they read on the internet...

I started watching and listening to people who Actually own Lithium batteries. Their good and bad stories , Ignored everyone else and formed my own opinion.

As stated, I was suddenly able to afford a medium sized pack. Even then, it took a lot of soul searching to make the switch.

I decided several things:

I decided to NOT use a BMS. (Many BMS failures, many people hawking their systems and stretching the facts, and no system did the things I considered important.-No I will not explain any of these-They are my opinions.)

I decided that maintenance was still maintenance. I just had to do it differently when switching from lead to lithium.

I found it hard to ignore the tremendous weight savings.

I considered the performance/capacity/C rate improvement a plus also.

Just the short time I have been actually driving the car, I really like the "normal" light/nimble feel to it due to the lack of 1,800# of batteries.

No opinion of the range improvement, too soon.

No opinion of the possible performance increase due to the switch from DC to AC system kinda screws a seat-of-the-pants Battery Comparison.

So far, I have found that some of things expounded in the forums about lithium is at best inaccurate. (More on that at a later date.)

I still believe that a Lead car is a good first "learner" car. OR a good vehicle for those with no other choice. (Lead or none, choose lead.)

In closing, a last question: My pack stops charging at 3.345 average/cell.
I have 1 that is 3.91/cell. I am going to pull that one down to the 3.345 area to match the others. Is 3.345/cell decent for a non-BMS pack, I think so.

THX, Miz

[JRP3]

I consider myself on the low side ending around 3.41V average at 20 amps, I'd say 3.345 is too low and not into the knee of the curve so you don't get a good idea of SOC, and leaving some real capacity on the table. Of course that depends on the current. What current are you at when ending charge?

[dragonsgate]

Thanks for the feed back Miz. I have been following this post off and on so I missed the part about the land deal. Your explanation and reasoning runs a pretty close parallel to my thoughts. Like I said I am far from being anti lithium I just can’t bring myself to putting that much money on a credit card. Thanks again for answering my question and I will now let you get back to your build.

[GizmoEV]

Originally Posted by mizlplix

In closing, a last question: My pack stops charging at 3.345 average/cell.
I have 1 that is 3.91/cell. I am going to pull that one down to the 3.345 area to match the others. Is 3.345/cell decent for a non-BMS pack, I think so.

THX, Miz

Originally Posted by JRP3

I consider myself on the low side ending around 3.41V average at 20 amps, I'd say 3.345 is too low and not into the knee of the curve so you don't get a good idea of SOC, and leaving some real capacity on the table. Of course that depends on the current. What current are you at when ending charge?

I'm with JRP3 on this too. Based on the resting voltage of my pack I think I'm getting 99-100%SOC on my charge to 3.465vpc ending charge at a few mA of current into my 200Ah pack. If I weren't into my "do cells drift" test I would try lowering the ending charge a little more and see how they do.

I did a test on one of my TS-LFP100AHA cells so I went back and looked at my data. For the data from a cell charging at 6A with a starting terminal voltage of 3.350V and ending at 3.451V with current at 476mA a total of 49Ah was added to the cell. From the point where the current started to taper back (terminal voltage was 3.421V) a total of 9Ah was added to the cell.

Ending current does matter. Ending charge at 3.6Vpc and 0.05C is similar to ending at 3.45-3.50V with current down in the 0.001C range.

HTH,

[tomofreno]

Here is a typical charging curve for one of my 180Ah CALB cells:
Charge Curve.pdf

I was charging at about 25A in this case, so you can see you have quite a bit of capacity left at 3.345V (each major time division is 2000 seconds). Charging current was tapering back during the exponential rise part of the curve, so I can't say how much charge was added there. You can see from the curve why JRP3 and Giz charge to around 3.45V - it is roughly at the start of the exponential part of the curve, voltage rises very quickly with added charge beyond that point. I should add, there is some variability in these curves cell-to-cell, with somewhat different slope on both the "flatter" and exponential part of the curve, but this curve is representative.

[mizlplix]

I have the 4th off, so I took the 5th and 6th to make a 5 day weekend.

My goal is to get it titled and plated.

I have two small wiring items to clean up and I will be ready for inspection.

Miz

[ricklearned]

Originally Posted by mizlplix

....I have two small wiring items to clean up and I will be ready for inspection.

Miz

Be careful where you drill holes for those wires. LOL

Enjoy your time off.

Rick

[mizlplix]

TODAY:

I want to wish everyone a GREAT 4th and also celebrate the greatest nation ever attempted by any peoples. As Cronkite used to say, "The great American Experiment is still working."


I have switched out my lead/acid aux. battery for a small 30AH pack of Headways I got from a vendor in Canada, (12/10AH cells,4S-3P) . There are also a pair of 3500MF/300Volt caps in parallel to try and dampen out the nasty pulses generated by my 3 coolant pumps, (so the headlights don't flicker.)

It is kept charged by a Meanwell 40amp DC/DC converter, with the voltage set at 13.2 volts (3.3Volts per cell).

It runs the car systems and lights easily.

I have yet to zero my ZEVA gauge setup as I keep messing with the 12VDC system and it would'nt stay calibrated.

After 3 charge-2/3rds discharge cycles, I have pin pointed my highest traction pack cell and now have a monitor on it. If it drifts too far, I can drain it down to nearer the rest of the pack.

Everything seems to be working well together-AC50/Curtis/CALB/Meanwell/Elcon.

Observation: I need a better shifter as reverse is hard to find.

(Good epitaph on my tombstone: I am always careful. Just sometimes I am a little more careful....)

Miz

[Ziggythewiz]

That little beastie looks great. How much was it?

[dragonsgate]

How much weight did you shave? Is that a bias ply tire?