Page 1
36V 9Ah eZee Flat Battery
Customized for Grin Tech
Specifications and
User Guide
Rev 1.0
Written by:
Grin Technologies Ltd.
20 E 4th Ave
Vancouver, BC, Canada
V5T 1E8
ph: (604) 569-0902
email: info@ebikes.ca
web: http://www.ebikes.ca
14 cm (5.6")
6 cm
(2.4")
35 cm (13.75")
Copyright © 2012
Page 2
1. Introduction
Congratulations on your purchase of this 36V 9Ah lithium iron
phosphate ebike battery pack. Our hope is that it provides you with
a solid 2-3 years of trouble-free power for your vehicle project.
2. Basic Usage
Rechargeable lithium batteries are easy to use.
needed and charge whenever convenient.
not need to be topped up at every available opportunity in order to
maximize their life, and unlike NiCad or NiMH, there is no benefit to
periodically running a deep discharge on the pack for
reconditioning.
You use them as
Unlike lead acid, they do
2.1. Discharging The battery has a short cable terminated
with red and black Anderson Powerpoles for plugging into your
motor controller. In order for the battery to function, the ignition key
switch must be inserted and turned all the way to the ON position.
Key must be pushed in
to turn all the way ON
Gnd
Batt+
The discharge wires of the battery pack are protected by a Battery
Management System (BMS) which will cutout if there is excessive
current or if any cells are flat. However, the discharge port does not
prevent overcharging either due to regenerative braking or charging
up via a power supply, so caution is required if current is allowed
into the pack by the discharge leads
2.2. Charging The battery is charged via a female 3-pin XLR
charging port on the side of the battery.
Page 3
Charger output should
be 43.5V, and no more
than 4 amps.
Pin 1 = V+
Pin 2 = Gnd
The maximum recommended charge current for this style of
connector is 5 amps. Even though the BMS will cut out the charging
port once charged to prevent overcharging, it is important that the
charger output does not exceed 43.5V. With a 4A battery charger,
the recharge time for a flat battery is 2-3 hours.
2.3. Storage If the battery will be stored for any significant
length of time, it is essential to at least partly charge the battery
beforehand, and top it up every 4-6 months. It is also a good idea to
turn the ignition key switch to the OFF position.
3. Important Safety Information
The danger of lithium battery fires has been widely reported and for
good reason. An ebike sized lithium battery pack contains sufficient
stored energy and volatile material that significant heat release and
damage occurs if something goes awry. Even though some lithium
chemistries such as LiFePO4 and LiMn are reputedly 'safer' than
other forms of lithium battery, none are 100%, and we have seen
close calls and dangerous situations with all types.
Always assume the worst could happen and only charge the battery
when you are around, or at the very least where any incident would
be contained such as in a concrete garage. Please don't leave
your battery charging unattended in a place where a fire could
result in loss of property or put people in danger.
Similarly, you should not charge the battery from the discharge
wires, as the BMS overcharge protection will not be functional, and
you should not discharge the pack from the XLR charging port, as
this can allow the cells to over-discharge.
Page 4
4. Special Features
4.1 Battery Rail Slide: The underside of the battery has a pair
of overhanging plastic rails that can slide onto the extrusion of a
custom carrier rack. eZee produces both a seat post clamp and
double decker rack with a compatible rail, while Grin manufactures
a universal twist battery anchor that can attach to most 3rd party
racks.
Lock Pin
Rail Slides
4.2 Locking Key Switch: The ignition key switch functions
both as an electrical ON/OFF control and also as a physical lock for
the battery. There are 3 positions, “open” retracts the locking pin
completely so that the battery can be removed from the rail. “Off”
still has the battery locked mechanically, while “On” both locks the
battery and turns on the output port. You cannot remove the key
from the “ON” position.
N
O
F
F
O
N
E
P
O
No Lock, Battery
Output OFF
N
O
F
F
O
E
P
O
N
Battery Locked
Output OFF
N
O
F
F
O
E
P
O
N
Battery Locked
Output ON
4.3. BMS Port: In addition to the 12 gauge red and black
discharge wires, there is also a small signal cable coming out of the
pack that is covered in shrinkwrap tubing. This is a communication
port to the BMS circuitry, and enables pack diagnostic and
troubleshooting without opening up the battery casing. A special I2C
-> USB communication board is required to use this.
BMS Communication Header
Page 5
5. Additional Details
5.1 Operation In Cold Lithium batteries have a noticeable
performance degradation at low temperatures (0 C and below). The
available capacity is reduced and the voltage will sag more under
load. There is no harm in running the battery at cold temperatures,
but we recommend storing the battery indoors so that it starts off in
a warmer state and thus can deliver better performance on the bike.
As well, you should not charge the battery at sub-zero
temperatures, as the optimum charge voltage for a cold battery is
less than a pack at room temperatures, and so you risk
overcharging the pack. For instance, a LiMn battery charged to
42V in the freezing cold may rise to 44V when warmed up.
o
5.2 Operation in Wet Weather The solid eZee plastic
enclosure provides good protection of the cells and circuitry from
incidental water spray. However, the seams are not fully sealed and
frequent exposure to rain and wet conditions can allow water
ingress into the casing. Over time this can corrode the cell terminals
and lead to erratic behaviour of the BMS circuitry. We suggest
covering the battery with a bag when exposed to water spray.
5.3 Flying / Travelling Air travel regulations prohibit flying
on passenger craft with lithium battery packs that have over 160
watt-hours of capacity, unless packaged to IATA standards as Class
9 dangerous goods. If you plan to travel with your ebike, you will
likely need to ship the pack separately to your destination using an
appropriate courier service.
5.4 Self Discharge in Storage Although lithium cells have
very low self discharge, the BMS protection circuit inside the battery
pack does draw a little current at all times. This BMS current is
small, but if the battery is already flat when initially stored, it will only
take a few weeks or months for this small current to further drain
the cells to the permanent shutdown threshold of the BMS, at which
point the pack can no longer be charged or discharged.
Page 6
To prevent this from happening, be sure to periodically recharge the
battery every 6 months while it is being stored.
If the battery is allowed to self discharge to the point of BMS
shutdown, then the only way to recharge the battery is to open up
the battery casing and trickle charge the cells directly, bypassing
the BMS circuitry, until all cells are >2.7V. At that point, regular
charging through the charge port is possible.
If the pack was allowed to self discharge to the point that some of
the cells are less than 1.5V, then safe recovery is not possible and
the battery should be recycled.
5.5 Battery Longevity
Battery cycle life is largely correlated with how much discharge
current the pack has to deal with. Heavy and routine usage at high
currents (>20A) will generally shorten the lifespan of a pack. The
lower your average current draw from the battery, the less it will be
stressed and the more cycles you will get.
This is a continuous relationship, not a hard cutoff. For instance, a
particular battery might deliver 600 cycles at 10A, 400 cycles at
20A, and only 250 cycles at 40A. Batteries also have a calendar
life that causes them to degrade over time whether being cycled or
not. So for those wanting to maximize their milage from the pack, it
is best to use it regularly but at only modest power levels (<25A with
this 36V 9Ah pack). Higher temperatures also reduce the battery
life.
For typical ebike riders, the pack will still be performing quite well
after 2 years of regular use, but by the 3rd year will generally be
ready for replacement. As a battery ages, you will notice more
voltage sag under load and less and less available capacity. If it
suddenly stops working altogether, that is usually a wiring or BMS
issue, not an end-of-life issue.
Page 7
6. Basic Troubleshooting
Discharge Wire
Charge Port
Possible Causes
~0V
30-42V
?Key Switch is OFF
?Key Switch is Broken
?Individual Cell <2.5V
?Water Damage
?Blown Output Fuse
0-20V
<29V
?Pack is at critical low
voltage shutdown from
BMS self discharge
–
0V
?Blown Charge Fuse
If the battery is not providing any voltage to the ebike, then it is
usually because the BMS circuitry has tripped or there is a break in
the discharge wiring. Use a multimeter to measure the voltage on
the discharge port, and also between pins 1 and 2 on the XLR
charging port.
Pin 2 = Gnd
Pin 1 = V+
It is normal that the pack capacity will gradually degrade over time.
However, if this seems to happen suddenly, it could be either
because some cells have become unbalanced, or the charger
output is not giving a full charge to the battery pack. Always check
that after a full charge your battery is at least 42V.
9. Disposal
Dead batteries can be returned for recycling through the
Rechargeable Battery Recycling Corporation (RBRC). See their
website for a map of nearest drop-off locations
http://www.call2recycle.ca/
Page 8
10. Specifications
Weight
3.85 Kg
Dimensions
348 x 141 x 59mm
Cells
36 pcs DLG 26650 LiFePO4 3C Cell
Typical Capacity
9.4 Amp-Hours (12S x 3P)
BMS Type
Programmable OZ8940 with Bleed Balancing
BMS Current
< 200uA Operational, < 20uA Sleep
Max Discharge Amps
29A (25A recommended for good cycle life)
Max Charging Amps
5A
Full Charge Voltage
42.5 - 43.5V
Internal Resistance
200 mOhm
11. Discharge Curves
Loading...