Tomberlin 44v lithium

First test with one 47ah 40lb pack versus 120ah 480lb lead pack.

Lonely pack under rear seat. Nothing under front seat.

Same power same top speed.

Lithium only at 3.7 per cell.

Looks like it will work at 44 volts just fine. I’ll put in a 24 pack parallel.
For 44v and 94ah.


48v DeltaQ only charging at 5 amps.:confused:

Not an issue.

After DQ trickled it to a proper lead voltage level, charger kicked into a 20a rate.
Good thing I was watching carefully.

I have the 44v 94ah pack in for testing.

44 volts is a deal killer. Not worth the trouble of battery swap. Even 400lbs lighter, car is a slug.

Made a test run at 60+ volts. Creeps up to 30mph. Still hasn’t come alive.:frowning:

Next is ~63 volts.

As this is 48v system, it’s a scary test.

Jumped right in at 18 cells. 66volts perks things up nice. 30mph at 1/4 throttle.

Voltage spoof is finally doing it’s job. A little more involved than the Gem fix.

Ready to mount an 18 pack and continue testing.

Battery mounts.
Lots of room.
I could fit the whole Chevy pack in here and it would weigh less than before.:smiley:

Ready to test at 68 volts measured.:eek:

Good performance with a 12s and 6s Chevy Volt in series.
Nominal 66 volts.

Stock programming and MM20% gives 30mph at 1/2 throttle.
20mph uphill.

Motor seems happy. Not overheating.

Controller requires “voltage fix” to accept higher voltage. (external mod)
Available soon if things work out.

Regen is somewhat aggressive.

Charged to 4v per cell. ie. 72 volts.

No smoke yet!
Motor is cool as a cucumber.

Mileage test with 47ah 18s pack. 66v nominal.
Start at 4.12v

30mph average speed.

2M 3.95
7.8M 3.78
11.6M 3.64 limp mode/flashing soc
13M 3.5 volts
end test

2008 Tomberlin E4 is 10.35 to 1 as tested today.
Tnx Rodney for package. I didn’t realize how much junk I stuck you with. :smiley:

Todays test -11v.

Switching from 66v to 55v nom @ 94ah.

Re-tapped a 22v pack to 11v parallel.

Lost a little uphill but still 30mph.

Might have to turn arm current back up.

Finished Tomberlin 30s battery install. 55 volt nominal should give me 25 mile range @ 30mph.

Still fine tuning “voltage fix” 12 volt works, but soc reads low. That may be ok as car will stop running at a higher voltage.

This controller works differently than T4. Requires a higher power device.

Easier install however. No re-pinning needed.

Works fine with armature current set to 175. Down from stock 255.
20mph uphill is fine.

Fine tuning needed.
Surging and slowing as soc indicator got near bottom.

Even though cells were 3.7.

Re-calibrated voltage fix to raise soc. Seems ok now.

Tried raising armature current to 225 then 200. Both settings lose top end and torque.:confused:

Put it back to 175. Seems to be the sweet spot.

15 hard miles, start and stop with hills. 4.1 to 3.6 v/cell.
Should squeeze 20- 25 easy miles out of 96ahs.

Not totally content with 55 volts.

Not that I’ve seen the performance at 66 volts, it’s hard to settle.

Same with Gem. 100 volts is sweet! (albeit risky)

Charging is working great using 12 X 10A CC-4V CV power supplies.

Makes me wish that I didn’t order the 4.2 volt chargers. Which are still not delivered.

I can build a 20s 5A charger for <$250.