Battery/Cells

From Unofficial Zero Manual
Jump to: navigation, search

The current manufacturer of cells for Zero's power packs is Farasis who are supplying pouch cells for the 2013+ model range (Gen2 and Gen3).

NMC Cell Chemistry
The chemistry used is Lithium Nickel Manganese Cobalt: LiNiMnCoO2 ("NMC" or other rearrangements of those letters).
NMC is a relatively new battery chemistry which differs from the Li-cobalt chemistry we are familiar with from mobile phone batteries and laptops.
While Li-cobalt has a higher energy density than NMC (storage capacity per kilogram), it doesn't cycle as well and ages quicker.
That's fine for a mobile phone that is likely to be obsolete after 2-3 years, but not for an electric bike.
The automotive-grade NMC cells that Farasis supply should easily satisfy the requirements of the five year warranty that Zero are providing with their current Z-Force battery packs.
It seems they should last 8-10 years if they aren't abused.
Even if you start to notice some significant deterioration after five years, the rate at which battery technology is progressing means that you should be able to buy a new battery pack with much better capacity (range) than the original for less money.
Battery Cells
Voltage
Years Form Manufacturer Model Datasheet Capacity Minimum Nominal Maximum Dimensions
2009-2011 cylindrical Molicel IMR-26700A Molicel 26700 [1] [2] 2.9Ah 2.5V 3.8V 4.2V±50mV 26.4mm ⌀ × 70mm
2012 pouch EIG EIG C020 EIG NCM C020 20Ah 2.5V 3.65V 4.15V 130mm × 217mm × 7.2mm
2013-2014 Farasis Farasis 25Ah Farasis IMP06160230P25A 25Ah or alt 25Ah 2.0V 3.65V 4.15-4.20V 161mm × 230mm × 6mm
2015 Farasis 27Ah 27Ah (25Ah label) 161mm × 230mm × 6mm
2016-2017 Farasis 29Ah 29Ah (28Ah label) 160mm × 230mm × 6mm
2018 Farasis 32Ah 32Ah (? label) 160mm × 230mm × 6mm
Farasis Claims
Per Farasis engineers and industry professionals:
25Ah
A solid cell, and are Farasis's oldest chemistry design.
They are a manganese-rich cathode (NMC) 25Ah cell with excellent cycle life, and acceptable C-rate.
27Ah
An adaptation of the 25Ah cell chemistry with thinner foils and more of them.
This means that there is more active materiel (more capacity) but less conductive path to get that capacity in and out.
So for the slow discharge S/DS bikes, you get more capacity, but they are lower C rate, and cannot handle being used in the FX platform.
29Ah
Higher discharge rate (peak and continuous) than the 25Ah cell.
More capacity than the 27Ah cell (especially at higher C rates/cooler temperatures).
32Ah
10% capacity improvement and very likely lower internal resistance.
Internal weight savings and better cooling are inferred.
Farasis Specs
Discharge Charge
Cell Continuous Peak (10sec) Max Burst Maximum
25Ah 4C (100A) 7C (175A) 400A 1C (25A)
References
2014 ZERO BATTERY CHEMISTRY (Z-FORCE® POWER TANK SECRET SAUCE)
DoctorBass on Endless Sphere: Zero Motorcycles BATTERY for your E-projects!!
Charged EVs: New (32Ah) Farasis lithium-ion pouch cell balances power and energy density
Battery notes from a Farasis Engineer. @ ElectricMotorcyleForum