Lithium Conversion (leaf battery)

[rottie]

thanks marianol.

I just got my last two modules in yesterday.
So I am waiting for the copper bus bar to show up so I can start drilling, cutting and connecting them for a 3 parallel module setup (currently in a two module parallel setup).

According to UPS, it should be here today. YAH!!!

Then it will be time to tear down the system, reconfigure, charge and reinstall.
Then change the throttle back to original for full power.

Love the plots. I will take another data set after the reconfigure.

[marianol]

Cool!!

The tool I used for the plots is Spotfire (http://spotfire.tibco.com/) I used the cloud version http://spotfire.tibco.com/products/spotfire-cloud but they also have a Desktop version http://spotfire.tibco.com/products/spotfire-desktop but I can't use it because it runs only in Windows.

Is really easy to use I just took me 2 minutes to pull those charts.

[Volt_Ampere]

Never heard of it before. I will have to check it out. I currently use Matlab or Octave for this kind of plotting but I like your plots better than mine.

[rottie]

next update...
Well I purchase the two extra modules and reconfigured the batteries in a
12S6P configuration, i.e. 50V at 180Ah.
I reset the throttle back to original (100%) and let it rip. Yikes it still moves like a scalded cat, barks the tires on asphalt pavement....

So I ended up settling of 75% for FWD throttle and 30% reverse throttle.
GPS max speed is ~19mph which is good, and throttle is nice w/o and controlled being crazy jerky.

I attached the log file for those that want to look at the results.
Now to see how many miles I can go on a charge, (thinking 50+)

[DaveTM]

Originally Posted by rottie

Now to see how many miles I can go on a charge, (thinking 50+)

Yes....BUT....can you do that thru swamp water WHILE being chased by a 15' gator for ten of those miles? Hey.....this "stuff" is important!! The upper 3% of the lower 5% of YOUR high school graduating class may want to know this some day!!

[rottie]

Well, IF I water proofed the battery compartment with the controller, then maybe?

Besides, that is why I have a boat for those deep water crossings.

[rottie]

long time no see, no hear.

I am back and still running my Lithium conversion with no issues, same original pack. Everybody I have shown it to and given rides are very impressed.
In fact, I now am converting a second one for money.

This is a Yamaha Limo. A looooong golf cart for 8 passengers.
Lots more room for batteries.
Looking at installing 24 leaf modules 48VDC. 12s8p. should get quite a bit of range even at full load on level ground.

[Volt_Ampere]

You want 14S I believe (7 modules) and then Three in series for a total of 21 modules. That gives you 58.8V max with 100% charge.

[Pat911]

Typo there I believe Volt_Ampare. I think you mean 3 in parallel.

7 modules in series is the correct number for a 48v system. 6 modules (12s) will give a nominal voltage of only 44.4v (3.7v per cell). It will work but performance will suffer.

[Volt_Ampere]

Yup. Typo - more like Brain Fart. My first cart has 14 modules, 7 in series, 2 parallel. Each module is two cells so it's 14S,2P. (Actually, each module has more than two cells in it but it appears to the outside connections as 2S.
My newer conversion has newer Leaf cells that are two modules with 7 series cells in each again 14S configuration. I think each module has three cells in parallel for each series cell but don't quote me on that. :-)