The 100 Volt Experiment

What is it?

I built a board with a 100 Volt battery - 24s1p using Molicel’s newest P45B 21700 cells in a TorqueBox.
I paired it with a Tronic 250R Controller and a SuperFlux motor.


Does it fit into a Stock XR box? No way! I had to use a Torque Box.

Why did I do it?

Mainly as an experiment in response to all the hype over the GTS’s 113 Volts (27s).
Also, P45B cells were only $6 on BlackFriday…

My objective was to demonstrate that 24s1p doesn’t make a whole lotta sense for most people. 18s2p in many aspects will be the better choice for most people.

After riding the 100V configuration for a few weeks, I will reconfigure the battery into a 12s2p and repeat some of those tests to see if it makes a difference (not the obvious ones!)

Expected Results - Obvious

These are the things that are well understood, so I’m not going to waste my time testing those:

Top Speed

Speed is proportional to voltage, 24s will run 20% faster than 20s when using comparable cells in both cases - that’s all.

Range

Range is primarily driven by Watthours (assuming equal cells). 24 x 3.6 x 4.5 is 388.8Wh, so that’s it.

For reference:
20s2p P28a is 403Wh
GTS aka 27s1p P45b is 437.4Wh
GT aka 18s2p P42a is 544Wh
18s2p P45B is 583Wh

*Stock XR is 324Wh

Now, you do the math - range is directly proportional to Watthours for those batteries.

Anecdotal Range Data from a San Clemente group ride:
13 Miles, 50% on hard single track, 2000ft of elevation drop/gain, 165lb rider - 3.25V/cell when finished (dip to 2.9V slowly going up my driveway). Reported Wh: 348 used, 52Wh gained (so 296Wh net)

GTS on the same ride was below 10%, didn’t let him ride any further (while I could have gone a bit more)!! NOTE: GTS rider was 185lbs, both our tires were just under 10psi.

MEAT pack SuperFlux/LFOCv3.1 had 40% left, 185lb rider!!!

Torque

Voltage has zero effect on torque really… google it…

Expected Results - Not So Obvious

How does higher voltage affect motor temperatures?

I expect no change and my first rides have confirmed that. More details to follow.

How does higher voltage affect efficiency

I expect no change and first tests have confirmed that. More details to follow.

Initial Results

Board rides great, just like any other VESC board I’ve ridden. Can I feel the 100 Volts? Nope, other than having a lot more headroom at any speed when looking at my phone.

Sidenote: Can the Tronic 250R handle the 100 Volts?

The Tronic is advertised as 100V max, but in reality all components from capacitors to MOSFETs are 130V+ capable, so there’s plenty of headroom. Out of an abundance of caution I still do not recommend using a saggy battery when going for 100V, so the P45B cells are the best possible choice there. 24s2p is obviously even better, but that’s impossible to fit…

will this work with a Hypercore FM motor?

Yes, no problem

10 Likes

this is awesome @surfdado
are you sharing the stl for the cell holder?
Thanks in advanced

look for surfdado on thingiverse @justintmars

2 Likes

Is there any concerns on braking regen amps for 1p?

Moli is very good for cell temps. As the P45B has a rated continuous of 4.5A and a max (with temperature cutoff) of 13.5A, you can probably hit a pulse max of 20A.
Regen current is usually something to worry about on large downhill sections. Bear in mind that the 50S used in the ME4T packs has a charge max of 6A * 2 = 12A. Combine this with the fact that a 100V system will use less current, and it becomes much less of a concern.

Do you know if the tronic will fit in a flowglider controller box or are the caps too tall?

Pretty sure it won’t fit the normal way since we tend to route the phase wires between the caps and the bottom of the box. I don’t think there’s any room left for the phase wires