2014 Zero Battery Chemistry (Z-Force® Power Tank Secret Sauce)

Wondering what Magic Chemistry Zero’s running in the new line and the Z-Force® Power Tank?  So was I.  Here’s the dish.  They’re Farasis NMC (nickel maganese cobalt, with a pure graphite anode) cells. 102 volts, 2.8 kwh, 28 in series for a total of 11.4 kWh without the addition of the Power Tank.  From the owners manual, it looks like it weighs around 52lbs for one of the two “power packs”.  That gives you a pretty awesome 120 kw/kg, by my math. (Correction – the “power pack” modules weigh 41.8lbs, as per Harlan Flagg at Hollywood Electrics. They are 2.8kWh. This calculates out to 149 kw/kg.)

Interestingly, the same cells they were using last year, but because the pack is so large, it’s providing significantly more amps – the old “higher peak amps from a lower c-rate” equation.  “They can really take the 660 amp controller to the max without voltage sag…”

Here’s the Farasis site, and here’s the data sheet on the battery: FEI-DataSheet-IMP06160230P25A-Pouch-25Ah-v5

5 responses to “2014 Zero Battery Chemistry (Z-Force® Power Tank Secret Sauce)”

1. Ted, thanks for sharing the secret sauce!

Hey, you meant 149 Wh/kg (specific energy), not 149 kW/kg (specific power). That got me thinking about the power possible from the 2.8 kWh (energy) Power Packs on the Zero FX. The Farasis datasheet you linked above says 7C peak discharge rate and 4C max continuous discharge rate. In terms of power, that’s 7 x 2.8 kW = 19.6 kW peak (10 sec) and 4 x 2.8 kW = 11.2 kW max continuous from one 2.8 kWh Power Pack.

Looking at the 2015 FX specs online (http://www.zeromotorcycles.com/zero-fx/specs.php), I see the Z-Force 75-5 motor is rated 20 kW on the Zero FX ZF2.8 model (with one 2.8 kWh Power Pack), whereas the same Z-Force 75-5 motor is rated 33 kW peak power on the Zero FX ZF5.7 model (with two 2.8 kWh Power Packs). So now we know where those power ratings come from. The Z-Force 75-5 motor has 33 kW peak power, but the Zero FX controller limits power from a single Power Pack to 20 kW (really it limits current to 175? A), hence the lowered power rating on the Zero FX ZF2.8 model motorcycle.

2. Still looking at Zero Motorcycles battery power. (2015 Zero S and SR specs are provided at http://www.zeromotorcycles.com/zero-s/specs.php)

The Zero S zf9.4 (smallest battery pack) Z-Force 75-7 motor is rated 40 kW, pack is 8.3 kWh nominal, controller is rated 420 A. The 1C current from the pack is 1C x 8300 Wh / 102 V = 81.3 A. At 7C peak discharge rate, the pack can deliver 7 x 81.3 A = 567 A. As stated before, the controller can deliver 420 A. And the motor can handle 40,000 W / 102 V = 392 A. So the Zero S power is limited by the motor, not the controller or pack.

The Zero SR zf12.5 (smallest battery pack) Z-Force 75-7 motor is rated 50 kW, pack is 11.0 kWh nominal, and controller is rated 660 A. The 1C current from the pack is 1C x 11000 Wh / 102 V = 107.8 A. At 7C peak discharge rate, the pack can deliver 7 x 107.8 A = 754 A. As stated before, the controller can deliver 660 A. And the motor can handle 50,000 W / 102 V = 490 A. So Zero SR power is limited by the motor, not the controller or pack.

So the Zero S and Zero SR each have well-matched motor, controller, and battery pack.

3. Bill, I was looking for just such calculations, and bam! there they were. Thanks, good job.

4. Hey I just noticed that the Zero S and SR have the same motor Z-Force 75-7 and that motor is rated 40 kW in the Zero S but 50 kW in the Zero SR.

Previously, I said “Zero S power is limited by the motor, not the controller or pack” but that’s not correct. Actually,
Zero S power is limited by the controller, not the motor or pack.

Here’s my reasoning: The same motor model–Z-Force 75-7–appears in the Zero S and SR. In the Zero SR, the 75-7 motor is rated 50 kW, so we know the motor can handle 50,000 W / 102 V = 490 A.

But the Zero S specs state that the Zero S controller can deliver 420 A (no more). Or in terms of power, the Zero S controller can handle 102 V x 420 A = 42.8 kW (no more).

To recap, the Zero S has a 50 kW motor, 42.8 kW controller, and a 57.8 kw (102 V x 567 A) battery pack. I.e. Zero S power is limited by the controller, not the motor or pack.

When you choose a Zero SR over a Zero S, you’re getting a more powerful controller and a larger battery pack that support the Z-Force 75-7 at 50 kW.

5. I read somewhere that the motor in the SR has been upgraded with better magnets to cope with the higher power and heat.