1. MAINTENANCE DIVISION TECHNICALSERVICEBULLETIN
BulletinNo.: FTSB2011-001 Date: March 17, 2011
Subject: Causesof Failure (PoorBatteryMaintenance)
DESCRIPTION:
The purpose of this bulletin is to inform all maintenance personnel about the causes of
equipment failure due to poor battery maintenance which contributes 5% over all the causes of failure
according to Caterpillar. The percentage might be small but if this problemis disregarded may result to a
much biggerproblemwhich will be explainedonthisbulletin.
Our battery plays an important role in our equipments electrical system. It stores electrical
energy from its chemical form and released as electrical energy for the machine’s electrical system.
Without it, the engine will not start. In a starting system, the battery converts electrical energy into
mechanical energy through starter motor in order to start the engine. In a charging system, mechanical
energy from the engine is converted into electrical energy with the use of alternator to charge the
battery. The charging system continuously supplies current in order to operate the electrical systems of
the machine.
Starting System
Charging System

2. MAINTENANCE DIVISION TECHNICALSERVICEBULLETIN
Most of our Caterpillar units are
controlled by ECM (Electronic Control Module).
An enclosed computer that is used to control the
equipment’s operation both engine and hydraulic
systems. The other function of an ECM is to
gather data for technical analysis when
diagnosed by CAT ET. It also controls the EMS
(Electronic Monitoring System) which serves as
an indicator to alarm the operator about the
currentstatus inreal time.
ECM works by analyzing input signals
from various sensors installed on the different
systems of the machine. The machine ECM
continuously monitors these input signals in order to control the output flow rate of the hydraulic
pumps, engine speed, fuel injection etc. The ECM sends output signals to energize solenoid valves,
relays,sensors andotherelectronicaccessories.
As a computer, the ECMprocess information through digital signal and analog signals. It supplies
5.0 ± 0.2 VDC to most sensors and a regulated voltage supply of 8.0 ± 0.4 VDC to the speed/timing
sensors to calculate engine rpm. And because of these parameters, our unit’s electronic systems are
sensitiveenoughtocertain variationof voltage.
A voltage fluctuation takes place when a battery kicks to a certain degree of voltage increase
due to instantaneous contact between positive and negative poles of the battery in which a spark
(electric arc) is mostly created between battery terminals and clamps (can also be found on connectors).
And since our equipment operates at 24 VDC, our battery is powerful enough to produce voltage that is
destructive toourelectroniccircuitry.
OBSEVATIONS AND FINDINGS:
AfterCATET Diagnosticswasperformedtoall Caterpillarunits,itwasfoundthatthere are numerous
error codesloggeddue topoor batterymaintenance.
To name a few,the followingeffectsare listedbelow;
 168-5 : Electrical SystemVoltage–CurrentBelow Normal
 168-1 : Electrical SystemVoltage–Low
 246-9 : ProprietaryCAN DataLink - Abnormal Update Rate
 269-4 : SensorPowerSupply –Voltage Below Normal
 588-9 : MonitoringSystemDisplay –Abnormal Update Rate
 590-9 : Engine Control Module –Abnormal Update Rate
 41-6 : 8 VoltDC Supply – CurrentAbove Normal

3. MAINTENANCE DIVISION TECHNICALSERVICEBULLETIN
The followingphotos are actual batteryinstallationfoundduringinspectionof units.
D8N Battery compartment and a closed up view of the battery showing a damaged terminal due to
loose clamping which have cause spark within its terminal area.
A battery clamp of BH-05 Corroded battery clamp
A disconnect switch with a welding rod engaged
to switch it on
The batteries without the fixture cover

4. MAINTENANCE DIVISION TECHNICALSERVICEBULLETIN
Battery grounding of D5M A Positive cable loosely attached to the clamp
BEST PRACTICE:
In response to correct or prevent recurrence of these failures, we recommend the following Best
Practice to be followedinordertoperformmaintenance proceduressuccessfully.
1. Strictlyimplementoperator’swalkaroundinspectionunderBLOWAF;
a. Checkbatterycables,itshould be tightlyboltedtothe clamp
b. Inspectclampsforcorrosions
c. Checkbatteryterminalsforcracks
d. Batteryfixturesmustbe inplacedtopreventmovementcausedbyvibration&swing
2. Use disconnectkeytoturnon/off the disconnectswitch (notweldingrod).
3. Disconnectswitchmustbe turnedoff aftermachine isparkedandremove key.
4. Use jumpstartcablesif batteryinstalledisdrained.
5. Refrainontransferringbatteriesfromone unittoanother.
6. Be sure to replace the batterywithanotherbatterythatisequal incapacityto the original.
There are many positive impacts associated with this Best Practice. Such positive impacts may
include: improved equipment reliability, maintenance and repair efficiency, high mechanical availability,
and improved mining operation performance. The impact of improving our battery management may
leadto greatersavingsonour equipment costresultingtogreaterproductivity andrevenue.
Preparedby:
Maximo V. Ginez III
Maintenance Planner
Notedby:
Chanito L. Ouano
Maintenance Division Head
Approvedby:
Francis Gerard S. Cañedo
President