Another lithium thread

Step one-buy 350lbs of batteries. 288 pack.
96-3 packs in series.
7-44v and 2-22v packs.

Couldn’t find any Nissan leaf cells. Found a Chevy volt.

Step two-stand back and admire them.

That’s as far as I go today.:slight_smile:

Have to do it the hard way of course.:rolleyes:

One idea if bms port can handle 10 amps.
And T4 can be set to 80 volts.

And for 48 v Tomberlin.

Use onboard charger daily.
Balance charger from Gem.

One or two plug in chargers take care of multiple cars and balancing.

Do you think one outlet will be able to handle 12 chargers simultaneously? Or, will you have to stagger-charge the 12 cells, or plug the chargers into multiple branch circuits?


10a 1s chargers are less < 100 watts each.

Thanks for input.

May build two chargers which could need two circuits if used at the same time.

Just in planning stages right now.
Lots of testing to do.

If bms ports won’t support chargers it will be messy.

Today’s project:

Reset my T4 72/80 volt controller to 80volts and measure effect.

If this is common knowledge let me know. It will save some effort.:smiley:

Assume bottom will go from 60 to 68 and top from 86 to 94.

If that works, I can try middle ranges and “out of range” settings.

It may only affect soc indicator output, which is not used in my car.

Set T4 voltage to 80 volts.
Baffling results.

When set to 72, lower volt level was 60, in limp mode.

Now set to 80, I’ve gone more miles without limiting.
Voltage dipping lower.
Still have power uphill.


These are my bad batteries, so not worried about damage.

Scaling was off a little. Corrected scaling shows no change in lower voltage threshold when changing from 72 to 80 volt setting.

Still at 60 volts.

And no change on 86 volt high limit. :frowning:

Back from what could prove to be a very expensive test run.:clap2:

90 volt gem T4.

Still worry about over voltage on regen.
As far as running, good so far.

Only have to push it another 5 volts, and I’ll have a 24 cell fix.:wink:

Chevy volt packs are 6 or 12 cell packs without tapping.

One is a 24 pack, that I’d like to drop in with cooling jacket in place.

This could go bad fast.:eek:

I have pushed past those limits , no problem s . Your going to have to eliminate 4 cells and run 20 to get voltages right. I’ve been thru all of this so let me know if I can help

Also just use your stock charger , cheap , easy and clean .

Never one to play it safe. Plan is to run 24 cells and see if controller can take it.

I tested the t4 from 92 volts and down . kept throwing error codes until it dropped to 86v . its been a while and I have forgot some of my research , what is full charge per cell on the volt batteries ? the leaf cells hold most their amps between 4.1v and 3.5v . when I did the calcs on using 22 cells the max they could be charged to was 3.9v . so they would have less capacity then using 20 cells charged to 4.1v . I am looking at adding one more cell (21 total) I could then charge them to 4.09v max which would increase their life span, get a little more range . but more important keep the voltage higher during heavy load .

your going to be impressed with the acceleration on just 20 cells . if you want range do 2 sets of 20 . this was my other option if I didn’t use the leaf cells .

The volt batteries are 12 and 6 packs.
Tapping them is a bother. I’d rather not.

Initial testing shows the T4 can survive higher voltages.
The error I can fix.

If I smoke it, I’ll cut back.

I’m up in the air on my 48 volt car.
Parallel 12s packs may be fine. Or even one.


I like your style . if you can figure out away to get the controller to function over 86v I’m interested. 90v would allow me to run 22 cells .

did you find specs on the volt cells ?

what’s the reason for not using a stock deltaq charger ? I had lithium profiles loaded in mine a year ago for less then $100 , works great .

I might use dq. After I settle on voltage.
Have to try the hard way first.
Do you know how high they will go?

Grant comes and goes, but last communication, he wanted to raise his T4 lower limit from 60 to 65.
Have something for him to try. It would raise upper limit by same amount.

The Gem T4s are dual voltage. 72/80 Tried the 80 volt setting, but it did not change the 60/86/96 volt window. :frowning:
At least not with my test.

I built him something that works with the “monitor” cable, that uses the same connections to T4.

Waiting to hear from him again.

#67: (48V 49.2V, 72V 73.8V, 96V 98.4V)
#128: (48V 54.7V, 72V 82.044V, 96V 109.392V)
#211: (48V 55.44V, 72V 83.16V, 96V 110.88V)
#163: (48V 57V, 72V 85.5V, 96V 114V)
#53: (48V 58.392V, 72V 87.588V, 96V 116.784V)
#123: (48V 59.88V, 72V 89.1V, 96V 119.76V)
#164: (48V 60.792,72V 91.188V, 96V 121.584V)
#135: (48V 62.256, 72V 93.384V, 96V 124.512V)
#161: (48V 64.44, 72V 96.66, 96V 128.88V)
#177: (48V 65.688V, 72V 98.532V, 96V 131.376V)

here are the profiles I had added . currently using
#128 . as you can see it well go all the way to 98.532v on a 72v dq if you want to go that high. if I add one more cell I well go to #163 to stay just below 86v. if you can override error codes and t4 well handle it then #123.

the notes I have for volt cells show 4.06v as the upper limit chevy uses . this is 87% soc . they don’t go anywhere near 100% soc to prolong battery life. I cant find a single discharge profile for these cells . are you going to do a discharge test to determine voltage ranges ? these are the same chemistry as the leaf cells so the discharge table for them is probably close .

Would you share those profiles?

Here is my charge profile from last night. Not lithium yet.

96.8 volt bump. Didn’t know it could go that high.
Never saw that before.