EarthX ETZ5G User manual

ETXLithium
BatteryUser’s
Manual
Copyright© 2017 EarthX, Inc. All rights reserved. The information contained in this document is the property of EarthX, Inc.
EarthX reserves the right to make changes to its documents or products without notice. It is the responsibility of each user to
ensure that all applications of EarthX’s products are as intended and safe based on conditions anticipated or encountered during
use. The EarthX logo is a trademark of EarthX, Inc
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E T X S E R I E S L I T H I U M B A T T E R I E S
Table of Contents
Overview........................................................................................... 1
Technology Inside.............................................................................1
Battery Cells....................................................................................1
ETZ - BMS ......................................................................................2
ETX - BMS......................................................................................2
ETX Hundred Series - BMS ............................................................2
Specifications....................................................................................5
Discharge Versus Temperature....................................................... 14
Self-discharge Rates....................................................................... 15
Discharge Curves............................................................................ 15
Installation....................................................................................... 18
Battery Installation.........................................................................18
Fault Monitoring Installation (ETX Hundred Series) ......................19
Vent Tubing Installation (ETX900-VNT)........................................22
Charging ......................................................................................... 23
Storage ........................................................................................... 25
Warranty ......................................................................................... 26
Troubleshooting .............................................................................. 26
Regulations..................................................................................... 27
Terminology .................................................................................... 27
I C O N K E Y
Valuable information
Caution

E T X S E R I E S L I T H I U M B A T T E R I E S
1
Overview
EarthX Lithium batteries are designed as a maintenance free replacement for the 12 volt
lead-acid or lithium batteries. To ensure a smooth replacement process, our batteries are
similar in dimensions to many OEM motorsport or power sport batteries. Our 12V
replacement lithium battery consists of 4 Lithium Iron Phosphate (LiFePO4) cells in series
and one or more in parallel with built in electronics to protect the lithium cells.
Our lithium cells together with our Battery Management System (BMS) create the safest
lithium battery on the market, with more starting power, and longer life.
The common features of our Lithium Batteries;
•Flexible battery connection –with center mounted terminals and terminal adapters,
the same batteries can be used in either left or right side polarity applications.
•Longer Storage Life –there is no need to float charge in the off season
•Environmentally Friendly –no hazardous chemicals and it can be recycled
•Fast Charge –can be fully charged in less than an hour (if charged at the maximum
recommended charge rate)
•Maintenance Free!
•No Special mounting direction (could even be mounted up-side-down)
•Will Not Freeze or Boil Over –Lithium batteries are dry cell technology and will not
freeze or boil ever
Failure to follow all application use, installation, charging, and storage instructions may result
in battery damage and or fire!
Technology Inside
Battery Cells
Our batteries use cells made of Lithium Iron Phosphate (LiFePO4). This chemistry is one of
the highest performance and safest on the market today.
Lithium batteries are fundamentally different than lead-acid batteries. A lithium battery
voltage remains relatively constant while discharging, while voltage for a lead-acid battery
decreases. A lithium battery’s storage capability is nearly 100% usable (measured as Amp-
Hour, Ah); while a lead-acid battery designed for motorsports typically only has 30% useful
storage. As such, 2Ah lithium battery has the equivalent “useable” capacity to a 6Ah lead-
acid. Also, a lithium battery’s cranking power is stronger, for the voltage while cranking is
generally higher. But when the lithium battery runs out of power it does so more abruptly.
LiFePO4cells by the nature of their chemistry are 3.3 volt. 12V lithium batteries are created
by using 4 cells in series (technically it is a 13.2 volt battery, but nominally full charge voltage

E T X S E R I E S L I T H I U M B A T T E R I E S
2
is >13.3V). Lead-acid batteries are made with 6 cells in series. Another difference is that
lithium cells are a dry cell technology, where the cells are packaged individually. As such, the
individual cell’s charge level will diverge with repeated charge/discharge cycles and age. This
condition reduces the performance of the battery (reduces capacity), for the battery charge
level is only as good as the charge level of the weakest cell. Moreover, charging a battery
with unbalanced cells results in one or more cells reaching the maximum charge (voltage)
level before the rest of the cells in the series, which leads to over-charging of the cell(s) and
eventual failure.
ETZ - BMS
All EarthX integrated BMSs continuously monitor each cell’s voltage as part of the cell
balancing and over-charge protection. If the voltage of a cell exceeds the others, the BMS
circuits will work to reduce that cell’s charge level. This ensures that the charge level of all
the cells remains equal, even with the high discharge (> 100Amps) and charge current
(>10Amps) of your vehicle.
A cell can be permanently damaged if over-charged (over-voltage) just one time. The BMS
has circuitry to disconnect the battery from the charging system (plug-in charger or your
vehicle) if the voltage exceeds 15.5 volts (an over-charge condition). The ETX Hundred
Series batteries have enhanced over-charge protection; see the ETX - Hundred Series section
below for more details.
The ETZ BMS has short circuit protection, but it is not resettable or repairable.
ETX - BMS
The ETX series BMS has all the features of the ETZ series, plus over-discharged protection
(completely draining the battery), excessive cranking protection, and short-circuit protection.
The BMS disconnects the battery from the load if it is drained to less than 5% remaining
charge (an over-discharge condition). An over-discharged battery typically has a voltage less
than 11.5V. If the BMS disconnects the battery, the voltage reading of the battery will be
zero volts. Excessive cranking protection logic includes temperature monitoring to limit
“high current use” (engine cranking) to 10 -30 seconds in any 60 second period. If the
battery terminals are “shorted” (or a low impedance load is connected across terminals),
which causes the battery volts to instantaneously drop to a very low level, the battery will
disconnect from the load to protect the cells and BMS from damage (short circuit
protection). If the BMS disconnects due to excessive cranking protection or short circuit
protection, the BMS will automatically reconnect after a cooldown period (typically 1-3
minutes). The ETX series is designed for short circuit protection > 1000 Amps.
ETX Hundred Series - BMS
The ETX “Hundred Series” was specifically designed for the experimental aircraft market
(models include the ETX680C, ETX680, ETX900, ETX900-VNT, ETX1200). Only the
ETX “Hundred Series” battery models are recommended for use as the primary aircraft
battery (starter battery). In addition to the features found in the ETZ and ETX series
motorsports batteries, critical electronic circuits are redundant, the over-charge protection is

E T X S E R I E S L I T H I U M B A T T E R I E S
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enhanced, and fault indication is included. All components associated with main electronic
battery disconnect are redundant. The built-in redundancy ensures that no single point
failure results in the battery unintentionally disconnecting. The design aligns with the
requirements for a FAA approved lithium battery as per RTCA performance specification
DO-347 and DO-160. Our ETX900-VNT includes a thermal run-away containment
system making it fully compliant to DO-347 specification.
In the event of a charging system failure where the voltage increases to above 15.5V, the
resistance to charging current increases, and above 16V the charging current is completely
blocked. The time delay for this feature is 1 second to allow the aircraft alternator’s over
voltage protection (crowbar circuit) to activate first. This design offers charge voltage
protection greater than 40V. The discharge current (current out of battery) is unaffected in
this situation. EarthX requires having automatic over-voltage protection (crowbar) for
alternator type charging systems (not required for <20 Amp pad mount standby alternators).
The battery’s micro-controller monitors all failure modes, and reports failures with a built-in
LED indicator and discrete output. The discrete output for external fault monitoring is a
single wire connection with a ¼” quick connect terminal. The output is a “current sinking”
type circuit (see diagram below) that can handle 100mA (connects the discrete output to
battery ground if a fault is present). This output can be connected to an external 12V LED
or general purpose discrete input of an EFIS. The fault output has two states; slow flashing
(5 second on/ 5 second off) or solid.
The slow flashing fault can indicate an improper state of charge or a problem with the cells
internal to the battery. If the battery voltage is outside the normal range of operation, 12.8V
to 14.6V, the battery is over-discharged or over-charged, most likely the result of an issue
with the electrical/charging system. If the battery voltage is within the normal operating
range, with a slow flashing fault, it is indicating an abnormal condition with a cell, such as
one cell’s state of charge is very different as compared to the other cells (high cell charge
level imbalance). The slow flashing fault may come on briefly during or following periods
of high current charging, and is not a concern. But if the fault persist, comes on
consistently during changing, or remains (charging or not), the battery will need to be
replaced.
The solid fault indicates a BMS hardware failure. For example, if the micro-controller fails
the fault indication output is activated (on solid). If the fault persist, comes on and stays on,
the battery will need to be replaced.