Expion360 EX-GC2 User manual

USER MANUAL
EX-GC2-48036

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DISCLAIMER
While every precaution has been taken to ensure the accuracy of the contents of this guide, Expion360
assumes no responsibility for errors or omissions. Note as well that specifications and product functionalities
may change without notice.
IMPORTANT
Please be sure to read the manual in its entirety before using the products. Misuse may result in damaging
the products, causing harm, or incurring serious injury. This manual will update periodically without notice.
Instead of saving this manual, view it on the Expion360 website for future updates and reference.
https://expion360.com/pages/customer-support
ABOUT US
•Safety
Expion360 lithium batteries use lithium iron phosphate (LiFePO4/LFP) chemistry, which is the best choice for
RV, marine, and off-grid power storage applications, because of its high degree of safety and long cycle life.
•Quality
With all the Li-ion manufacturers in the market, Expion360 strives to ensure that our products meet the highest
quality standards to maintain our advantage over the competition. Expion360 battery uses cylindrical 26650,
stainless steel encased LiFePO4 cells. The cells are UL 1642 recognized (File No. MH64383). They are
certified to the highest standard in safety and performance. Instead of soldering, all internal connections are
mechanically fastened to reduce resistance and ensure long-term durability.
The Expion360 proprietary case contains internal structural support to protect the battery pack and BMS
inside from the effects of vibration and movement. The innovative oversized terminals and bus bars provide
substantial electrical connections to accommodate high ampacity cables.
•Service
The Expion360 technical support department has industry experts on standby to assist you, our valued
customers, in every way we can. If for any reason you require assistance with our products, contact us by
phone or email any weekday during business hours and receive help from the best technical support in the
industry.
[e-mail]
[phone]
Monday to Friday except for holidays
8 am - 4 pm PST

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Please Read Each Warning Carefully to Prevent Damage to the Unit and Injury to Operators.
Ignoring Warnings Voids Warranty.
WARNINGS:
DO NOT drop the battery.
DO NOT cut open the battery.
DO NOT short circuit the battery.
DO NOT submerge the battery in water.
DO NOT use the battery as a starter battery.
DO NOT attempt to repair the battery if it malfunctions.
DO NOT mix batteries of different ages, voltages, capacities, or manufactures.
DO NOT ignore battery installation guidance.
DO NOT undersize battery cables.
DO NOT undersize the battery system.
DO NOT connect EX-GC2 batteries in series.
DO NOT connect more than FOUR batteries in parallel per string.
DO NOT connect an unequal number of batteries in parallel on each string.
DO NOT charge the battery with any profile other than 48V LFP.
DO NOT charge the battery above 58.4V.
DO NOT charge the battery at or below 32 °F.
DO NOT charge the battery above its maximum charge rate.
DO NOT discharge the battery below 40.8V.
DO NOT discharge the battery at or below -4 °F.
DO NOT discharge the battery above its maximum discharge rate.
DO NOT connect the battery to any load while in long-term storage.
DO NOT operate or store the battery outside the specifications of the manual.

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Table of Contents
DISCLAIMER ...................................................................................................................................... 2
IMPORTANT ...................................................................................................................................... 2
ABOUT US ......................................................................................................................................... 2
WARNINGS: ....................................................................................................................................... 3
1Overview ........................................................................................................................................... 5
2Battery Specifications ......................................................................................................................... 6
3Battery System Sizing ......................................................................................................................... 7
4Battery System Installation .................................................................................................................. 9
5Charging ......................................................................................................................................... 10
6Cycle Life ........................................................................................................................................ 11
7Storage ........................................................................................................................................... 11
8Protection ....................................................................................................................................... 12
9Bluetooth and Expion360 App............................................................................................................. 12
10 Warranty ......................................................................................................................................... 13

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1Overview
The Expion360 GC2 LiFePO4(Lithium Iron Phosphate, LFP) SmartTalk Battery is specifically engineered for light
electrical vehicle (LEV) and golf cart (GC) applications with Bluetooth functions. The Expion360 GC2 battery provides
more than twice the continuous power and energy output of a lead-acid battery in the same size. With the Expion360
app, users are allowed to check the battery's health and conditions with ease.
Converting a lead-acid LEV or golf cart to lithium-ion is not a simple process, which may require modifications to the
battery charger, motor controller, and motor. The Expion360 GC2 LFP battery is less than half of the weight of a GC2
lead-acid battery. The vehicle’s handling will change, which may require modifications to the vehicle frame and
suspension to maintain safety.
To prevent damage to the vehicle and injury to operators, please consult with dealers, reputable vehicle upfitters, or
Expion360 technical support for any concerns.
This document provides guidance solely on the Expion360 GC2 battery in LEV and golf cart applications. For all other
applications, please consult dealers or Expion360 technical support before installation.
•Required Tools
Torque Wrench, 13mm Socket
•Accessories
Expion360 app, Communication cable, Battery system monitor (optional)
•Diagram
1
Battery System Monitor and
Communication Port
2
Negative Terminal
with Two Threaded M8 Holes
3
Discharge On/Off Switch
Discharge On: Indent
Discharge Off: Flush
4
Positive Terminal
with Two Threaded M8 Holes
5
Communication Port

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2Battery Specifications
Parameters
EX-GC2-48036
Electrical
Battery Nominal Voltage
51.2 Vdc
Battery Rated Capacity (@ 0.2C, 25 °C)
36 Ah
Battery Rated Energy (@ 0.2C, 25 °C)
1843.2 Wh
Battery Internal Impedance
(@ 1kHz AC, 25 °C)
≤50 mΩ
Battery Self-discharge Rate (@ 25 °C)
<5 % per month
Battery Cycle Life (80 % Capacity retention)
(@ 0.2C / 1C, 25 °C, 100 % DoD)
>4000
Max. Parallel Connections (per string)
4
Communication
Bluetooth, CAN Bus, Display
Mechanical
Battery Size
BCI GC2
Battery Dimensions (L. x W. x H.)
10.24 x 7.13 x 10.85 in (260 x 181 x 276 mm)
Battery Weight
38.5 lb (17.5 kg)
Case Material
ABS
Terminal Material
Brass
Terminal Thread
M 8 x 1.25 - 12
Terminal Torque
8 lb-ft (10 Nm)
Cell
LiFePO4
Charge
Method
CC-CV
Voltage
Max. Range
56.8 Vdc to 58.4 Vdc
Optimal Target
55.2 Vdc
Protection
58.4 Vdc ± 0.8 Vdc
Protection Release
53.6 Vdc ± 0.8 Vdc
Current
Optimal
0.2C
7.2 A
32 °F to 50 °F (0 °C to 10 °C)
<0.2C
<7.2 A
50 °F to 140 °F (10 °C to 60 °C)
<0.5C
<18 A
Max. Regen Protection
2C
72 A ± 3 % (10 s ± 0.5 s)
Protection Release Condition
Remove load, release after 30s. After 10 consecutive
protection events, release after 10min.
Temp.
Operating
32 °F ± 9 °F to 140 °F ± 9 °F (0 °C ± 5 °C to 60 °C ± 5 °C)
Protection Release
40 °F ± 9 °F to 120 °F ± 9 °F (5 °C ± 5 °C to 50 °C ± 5 °C)
Protection Release Condition
Temperature meets protection release conditions.
Discharge
Voltage
Optimal Shut-off
44 Vdc
Protection
40.8 Vdc ± 0.8 Vdc
Protection Release
44.0 Vdc ± 0.8 Vdc
Current
Optimal
1C
36 A
Max. Continuous
2C
72 A ± 3 % (10 s ± 0.5 s)
Max. Pulse
3C
108 A ± 3 % (3 s ± 0.5 s)
Protection Release Condition
Remove load, release after 30s. After 10 consecutive
protection events, release after 30min or charge.
Temp.
Operating
-4 °F ± 9 °F to 150 °F ± 9 °F (-20 °C ± 5 °C to 65 °C ± 5 °C)
Protection Release
5 °F ± 9 °F to 130 °F ± 9 °F (-15 °C ± 5 °C to 55 °C ± 5 °C)
Protection Release Condition
Disconnect load.
Temperature meets protection release conditions.
Short
Short Circuit Release Condition
Remove load.
Storage
Recommended Voltage
54.0 Vdc (about 50 % SoC)
1 month
-4 °F to 113 °F (-20 °C to 45 °C)
3 months
-4 °F to 95 °F (-20 °C to 35 °C)
6 months
-4 °F to 77 °F (-20 °C to 25 °C)
Maintenance
Discharge-charge cycle every 6 months.

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3Battery System Sizing
DO NOT undersize the battery system.
Consider these three parameters when determining the size of the battery system.
•Battery Rated Energy
Golf carts can travel from 4 to 8 miles per kWh. One EX-GC2-48036 battery has a rated energy of 1.8kWh, so the
equivalent range per battery is 7.2 to 14.4 miles.
Assume:
One EX-GC2-48036 battery can provide 10 miles of drivable distance
You plan to play an 18-hole course N times (N = 1, 2, 3, …)
An 18-hole golf course is about a 10-mile drive
A one-way travel distance is D mi
Number_of_batteries_1 = (D + 10*N + D)/10 mi
E.g.:
You plan to play an 18-hole course 2 times
An 18-hole golf course is about 10 mi drive
A one-way travel distance is 6 mi
Number_of_batteries_1 = (6 + 10*2 + 6)/10 mi = 3.20
•Battery Maximum Pulse Discharge Current
Find the maximum INPUT pulse power on the motor or maximum INPUT pulse current on the motor controller.
Assume:
The maximum input pulse power on the motor is P_max
I_pulse = P_max/40.8V
Number_of_batteries_2 = I_pulse/108A
E.g.:
P_max = 16kW
I_pulse = 16000W/40.8V = 392A
Number_of_batteries_2 = 392A/108A = 3.63

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•Battery Maximum Continuous Discharge Current
Find the rated INPUT power on the motor or rated INPUT current on the motor controller.
Assume:
The maximum input rated power on the motor is P_rated
I_cont = P_rated/40.8V
Number_of_batteries_3 = I_cont/72A
E.g.:
P_rated = 10kW
I_cont = 10000W/40.8V = 245A
Number_of_batteries_3 = 245A/72A = 3.40
Round up the maximum number of Number_of_batteries_1,2,3 to be the number of batteries for the battery system.
E.g.:
Number_of_batteries_1 = 3.20
Number_of_batteries_2 = 3.63
Number_of_batteries_3 = 3.40
The number of EX-GC2-48036 batteries for this installation is 4.
•Quick Reference Sheet
Energy Pulse Current Continuous Current
Number of courses
N
One-way distance
D
Max pulse current
I_pulse
Max continuous current
I_cont
Calculation result Number_1
= (D + 10*N + D)/10
Number_2
= I_pulse/108
Number_3
= I_cont/72
Battery system size
Max (Number_1, Number_2, Number_3)
The decision to expand the size of the existing battery system should be made early on. Check the
cycle count of each battery on the Expion360 app.
Extra batteries can be added if the existing battery system cycle count is less than 50. However,
the existing battery system may need to be reconfigured.
DO NOT add new batteries if the cycle count of the existing battery system exceeds 50 cycles.

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4Battery System Installation
Improper Battery System Installation Voids the Warranty
The depth of the battery terminal thread is about 12 mm. Consider this when determining the proper M8 bolt length to
secure bus bars, cable lugs, and any washers that will be affixed to the terminal. Torque the screws to 8 lb-ft (96 lb-in).
Make sure the discharge switch is OFF when operating. Click on the switch to the ON position after completing
installation. The battery can be charged regardless of the switch position.
Use AT LEAST 2 AWG cables when connecting multiple GC2 batteries for optimal performance. Make sure the battery
cables are the same gauge, equal length, and as short as possible. Check the current of each battery on the Expion360
app. Make sure the difference between the current of each battery and the average current is within the 5% range of the
average current. Otherwise, check the battery system wiring and make sure the system is installed correctly.
More details about battery system installation can be found in the Battery System Installation Guidance.
expion360.com > Support (drop-down tab) > Customer Support
or visit https://expion360.com/pages/customer-support
•Series Installation:
DO NOT connect EX-GC2 batteries in series.
•Parallel Installation:
Connecting batteries in parallel increases the continuous/pulse charge and discharge rates, as well as the battery
system capacity. This leads to an extended range and the ability to operate a more powerful motor.
Up to 4 batteries may be connected in parallel on one string. To further increase the battery system’s overall capacity,
additional strings may be connected to a power distribution block using cables of equal length.
Avoid configuring the battery system with 5 batteries, due to balancing issues. Instead, configure the battery system
with 4 or 6 batteries.

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5Charging
The optimal and maximum charge rates of a battery system are equal to the rates of an individual battery multiplied by
the number of batteries connected in parallel.
E.g.:
A battery system has (4) 100 Ah batteries connected in parallel. The capacity of the battery system is
400 Ah. The optimal/maximum charge rate of a single Expion360 battery in this system is 20/50 A at
0.2/0.5C. The optimal/maximum charge rate of the battery system is 80/200 A (0.2/0.5C).
Use the optimal charge rate (0.2C) to prolong the battery’s life. The battery system can be charged at a maximum charge
rate of 0.5C for rapid charging if the temperature conditions listed in the Battery Specifications section are met. Never
charge the battery system above the maximum charge rate. Please consult the Battery Specifications for information on
the optimal and maximum charge rates of the battery in various temperature conditions.
If batteries have been discharged to 0% SoC, they must be recharged within one week to prevent
damage to the batteries and avoid voiding the warranty.
•Charger Options
Expion360 GC2 batteries should be charged by a CC-CV two-stage LFP profile charger. The charge current/voltage
should be in the listed range and never exceed the maximum charge current/voltage of the battery system. See Battery
Specifications for details. It is recommended to charge the battery after use every time.
•Charger Sizing
Once the battery system has been appropriately sized, the specifications for the charger can be determined based on
the preferred charge rate or time. A 5-hour charge time is recommended to maximize the life span of the battery.
Assume:
The desired charging time is T = 8 hours
The number of EX-GC2-48036 in the battery system is N=4
The rated energy/capacity of EX-GC2-48036 is 1.8kWh/36Ah
The 48V CC-CV LFP charger power and current are P_chrg and I_chrg
E.g.:
P_chrg = Battery System Rated Energy / T = 1800Wh*4/8h = 900W
Or
I_chrg = Battery System Rated Capacity / T = 36Ah*4/8h = 18A
The charger's calculated current must be lower than the maximum charging rate of the battery system.

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6Cycle Life
The battery is considered to reach the end-of-life (EoL) when the remaining available capacity is less than 80% of the
original capacity. Many factors can affect battery cycle life, such as depth of discharge (DoD), charge/discharge rate,
and temperature. Optimizing these factors can extend battery life.
•DoD (Depth of Discharge):
The cycle life is tested by cycling the batteries at 100% DoD. The optimal window for operating LFP batteries is between
20% and 80% DoD. To accommodate this, slightly oversize the battery system so that each cycle is about 80% DoD.
•Operating Temperature Range:
Operating the battery at extremely low or high temperatures will significantly decrease the battery cycle life. Make sure
the battery system is ventilated or cooled at high temperatures and heated at low temperatures. Maximum battery life
can be achieved when operating temperatures are as close to 77 °F (25 °C) as possible.
•Charge/Discharge Rate:
Charging and discharging the battery at higher than recommended rates will generate more heat within the cells. Since
temperature is the primary factor that affects the cycle life, consider the charge/discharge specifications with regard
given to ambient temperature extremes when configuring the battery power system. The specifications consider both
safety and the maximum cycle life when recommending optimal parameters for the battery system.
•Storage:
Most users will see batteries in storage more often than active daily use. To prolong the battery life during periods of
storage of one month or longer, please consider the storage conditions.
7Storage
If batteries are fully discharged to 0% SoC, immediately charge the battery system to 50% or an open circuit voltage of
about 55.2 Vdc and confirm that all positive and negative cables have been disconnected from the battery terminals. All
batteries using LiFePO4chemistry will be permanently damaged if discharged to 0% SoC and left for over one week. This
is not a design flaw but is an inherent characteristic among all Lithium Iron Phosphate batteries.
The Expion360 warranty excludes coverage for such damage due to neglect of the batteries by the end user.
Properly storing the battery system between 20% and 80% state-of-charge (SoC) will prolong the battery life. Completely
discharge and charge the battery system every 6 months to extend the battery life.
For long term storage or when the minimum temperature is BELOW FREEZING, return the button switch to the flush
position and isolate the battery system from any loads and charging sources. The BMS only measures the SoC of the
battery pack during charging and discharging, and it cannot measure the battery self-discharge. Due to the inherent self-
discharge of all batteries, it is advised to check the voltage periodically. If at any time the voltage is below 48 Vdc, check
the battery system and make sure it is completely disconnected from any load. Charge the battery system to 50% and
disconnect the charger. Isolate the batteries from the charger and load source.

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Please follow the guidelines below for lengths of storage time and temperatures.
1 month: 20% - 80% SoC, -4 °F to 113 °F
3 months: 20% - 80% SoC, -4 °F to 95 °F
6 months: 50% SoC, -4 °F to 77 °F
For short term storage or when the minimum temperature is ABOVE FREEZING, return the button switch to the flush
position and connect the system to a charger.
8Protection
The Expion360 GC2 battery is purpose-built for golf carts and other LEVs and includes specialized features to ensure
optimum performance and safety. The integrated BMS provides outstanding safety features, including multiple levels of
protection for discharge current and regenerative braking. For details and troubleshooting, see Battery Specifications.
The regenerative brake has minimal benefit in terms of energy recovery for golf carts, instead, it may heat the batteries
and potentially reduce the battery life. Choose a regen level that isn’t too aggressive and strikes a balance between
performance and comfort. If the regen level exceeds the maximum regen current and duration, BMS protection will
activate, leading to a significant reduction in the vehicle's braking power. Please note, 10 protection events will
temporarily lock the batteries. It is highly advised to test the system regen settings and validate the braking system
before use. If needed, add more batteries to the battery system to accommodate higher regen current.
A braking resistor is an essential component of the golf cart braking system for safety. Serious injury or death may result
from operating a golf cart without a braking resistor.
It’s important to obtain expert assistance when converting a golf cart from a lead acid system to an LFP battery system.
9Bluetooth and Expion360 App
The Expion360 app is available for download on both the Apple App Store and Google Play Store. Detailed instructions
for the app can be found in the Expion360 App Walkthrough. The walkthrough can be found at:
expion360.com > Support (drop-down tab) > Customer Support
or visit https://expion360.com/pages/customer-support
To conserve energy, the Battery Bluetooth module will enter sleep mode after being idle for an hour. Charging,
discharging, or toggling the On/Off switch will wake up the Bluetooth module.
The number of devices that connect to the phone simultaneously will affect the battery life of the phone and the stability
of Bluetooth connections. The stability of the Bluetooth connections can also be affected by the surroundings of the
batteries. For example, a metal battery enclosure may weaken or disrupt Bluetooth signals.
Due to a limitation within the iOS and Android operating systems, the maximum number of devices that can connect to
a cell phone simultaneously will differ. According to our testing, the iOS system can connect to 8 devices simultaneously,
whereas Android is able to connect to 6 devices at a time. If more devices need to be connected, the battery system can

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be configured as multiple battery sub-systems on the Expion360 app. These different sub-systems can be accessed
from the app to display sub-system information when needed.
E.g.:
If you have a battery system that contains 16 batteries, your phone is not able to connect to them all simultaneously. You
can separate the battery system into multiple battery sub-systems, virtually. Each battery sub-system represents one string
of batteries. As depicted below, the battery system is separated into two battery sub-systems – GC Demo 2 and GC Demo
3. Each battery sub-system can be selected from the drop-down battery system list (top left corner) to activate the Bluetooth
connections and display the sub-system information.
More details about battery sub-systems (strings) can be found at Battery System Installation and Battery System
Installation Guidance.
10 Warranty
Please refer to the Expion360 GC2 Battery Warranty for details. The Warranty can be found at:
expion360.com > Support (drop-down tab) > Customer Support
or visit https://expion360.com/pages/customer-support