Sentinel System

System Parameters Option 1 Option 2 Option 3
Block Voltage
String Voltage
String Current
Ambient Temperature (room)
Upgrade Path

The Sentinel Battery Monitor introduces a continuous data collection tool into a battery system structure. This data is stored in a database format providing real time and historical reporting capability. The storage format provides the ability to view data past or present to the level of detail necessary for specific requirements.

  • User set alarm functions to alert maintenance personnel of necessary actions
  • Substantially increases cost effectiveness of battery maintenance program
  • Reliably provides records for internal or external requirements
  • Does not introduce a failure mode into battery system operation

System Summary

The Sentinel system utilizes sensors (M-Senzor) integrated into wiring harnesses attached to the posts of the battery. The span of these connections is limited based on the smallest single unit of measurement and the largest single unit of measurement as follows:

  • The smallest single unit of measurement is defined by the availability of battery posts. This can be a cell or a jar of multiple cells depending on battery configuration.
  • The largest single unit of measurement is defined by the maximum span of a wiring harness which is 3 feet (can be 1 foot to 3 feet in length). The maximum span is defined by resistance of the wiring harness as a function of length.

The preferred deployment of the system is measurement of individual cells, jars, or monoblocks at design voltage.


Each wiring harness supports a m-Senzor which reads a maximum number data points defined as follows:

  • Voltage potential between posts
  • Ohmic resistance between posts including the terminal assembly (via the introduction of a sinusoidal electrical wave function)
  • Battery temperature as measured at the negative post.

Current flow is the same throughout the string and is measured by the current transducer at a single point and not by each m-Senzor. This data is measured continuously in all states; float, charge, discharge.

The data is transported from the sensors in digital form via a RJ9 cable. Sensors can be bridged together up to a maximum of 10 sensors per chain via an RJ9 connection. Thus you can have 1 to 10 sensors per chain which is fed into 1 port on the Sentinel. There are 8 available ports on the Sentinel providing for up to 80 sensor units per Sentinel unit. To provide for more than 80 sensors the additional Sentinel units are used in a master/slave configuration.

A single hardware system will cover from 1-1280 jars in any arrangement.


Failure of a single sensor unit in a chain has no effect on the data being sent from the remaining sensor units, and failure of a single port on a Sentinel unit has no effect on the data being accumulated via the remaining ports. Additionally, failure of a Sentinel unit a multiple unit hardware arrangement has no effect on the remaining Sentinel units.

If the failure is a master in a master/slave multiple unit deployment, the master can be removed and replaced and the slave will maintain its configuration and step back online. However the master does control the system and also provides the point of connection for external communications. If the master goes down, the system as a whole is effectively down until the master is replaced. The data stored in the slaves is retained once the system is back online to the maximum onboard storage capacity of each Sentinel unit.

The data is polled every 4 seconds except for Ohmic resistance which is polled daily. It is also dependent on battery status – the resistance measurement will not occur if the batteries are not floating. This data can be read real time via the Link software interface available from PowerShield, or existing client software via a Modbus or other connection. These interfaces can work simultaneously as there is no conflict between communication ports.


The historical data is stored in the Sentinel unit for 24 hours before being dumped into the software interface, or a user can force a memory download at any time manually. A force download will not interfere with the software based scheduled download. The data is stored in the software interface in database form allowing for real time and historical data at any level of detail required, and at any time. Reports can be generated directly from the Link software, or from the client provided software as required.

Alarms are set via configuration software which are shown on the Link software interface. An alarm will remain until it is manually adjusted on the software to identify the action taken. Alarms can also be sent directly from the Link Software via e-mail or text messages (requires LAN or WAN connectivity for the computer running Link).

The Sentinel hardware system can be connected to the Link software interface, to the clients existing software interface, or to both simultaneously.