ELK BLT Specsheet

ELK-BLT Battery LifeTester

Application

The ELK-BLT Battery Life Tester or “Mhos Meter” is a
compact, easy to use service tool for testing 12 Volt
rechargeable batteries. The BLT measures internal
conductivity (Mhos), which is the best indicator of a
battery’s health and life expectancy. Mhos happens to
be the inverse of Ohms (conductance as opposed to
resistance). The BLT operates as follows: For each
battery brand and size installed you should start by
measuring and recording a “baseline” Mhos reading.
Then, during any service call or inspection simply
measure and record the current (most recent) Mhos
reading. Always compare the current Mhos reading with
the original reading. Self-adhesive test data labels may
be used for recording each inspection. When the
current Mhos reading has reached at or around 71% of
the original baseline then it is time to consider changing
the battery. The BLT includes a reference chart on the
back with numbers equating to Mhos readings for
common security industry battery sizes.

a.k.a Battery Mhos Meter ver 3.0

The BLT receives its operating power from the battery
under test and automatically warns when the battery
voltage is too low for testing.

Features

• Does not discharge or damage the battery.

• Tests 12 Volt Rechargeable Batteries.

• Display Shows Battery Voltage and Mhos.

• Warns if battery voltage is too low.

• Replaceable test leads.

• Includes padded carrying case.

• Includes self-adhesive test data labels. **

• Lifetime Limited Warranty.

Specifications

• Operating Voltage: 10.0V - 14 Volts D.C.

• Current Draw: 1.1 Amps Max., 0.0016 Ah for full test.

• Battery Leads: ~12 Inches.

• Size: 4.4” W x 3”H x 1.15”D w/o carrying case.

** To reorder a pack of 100 test data labels specify: ELK-BLT LABELS.

PO Box 100 • Hildebran, NC 28637 • 800-797-9355 • 828-397-4200
Fax [phone] • www.elkproducts.com • [e-mail]

03/1/08

ELK

PRODUCTS, INC.

Instructions

BLT measurements should be taken and recorded periodically. The popular method is to record the information onto self-adhesive
labels placed directly onto the battery. A supply of these labels is included with the tester. Additional labels may be ordered in
packs of 100 by specifying part number ELK-BLT LABELS. This information will be valuable in future tests for trending analysis.
The recorded data should include:

A. The Date of the test.
B. The Battery Voltage reading. (optional)
C. The Mhos reading.

1. Disconnect the battery from it’s equipment.

2. Connect the BLACK test clip to the Negative (-) battery terminal, and the RED to the Positive (+) terminal. (For accurate

readings, the test clips must be tightly clipped directly to the battery posts, not to the battery bolts).

“Err” or blank indicates battery voltage is too low for testing or a test clip connection is loose.

Try charging the battery or reconnecting the test clips.

3. The Voltage of the Battery will display briefly. A new battery, out of the box, will generally read around 12.6 Volts. A fully­charged battery should read between 12.6 Volts and 13.5 Volts.

“- - -” indicates test in process, please wait.

ELK - BLT

4. The Mhos (internal conductance) reading of the battery will display within 6 seconds.

ON NEW INSTALLATIONS:
4a. Record the Mhos reading and the date of test on the test data labels or on the battery housing using a permanent marker.

ON SERVICE CALLS OR INSPECTIONS:
4b. Compare the latest current Mhos reading to the original baseline Mhos reading previously recorded. Then calculate the
percentage difference between the baseline and the current Mhos reading (the decline). If the Mhos has declined to 71% or
lower from the baseline Mhos reading the battery should be replaced. NOTE: If a calculator is not convenient then use the
Battery Mhos Reference Chart on the back of the BLT to locate the value closest to the baseline recorded on this battery. The
middle and right hand columns represent the value at 81% (weak) and 71% (replace) respectively.

E.G. Baseline - 180 Mhos Weak - 180 Mhos X .81 = 145.8 Mhos Replace - 180 Mhos X .71 = 127.8 Mhos

NOTE: No standard Mhos values exist for any battery size or brand. In some cases, different production batches of
the same brand battery will produce different readings. RARELY will any “similarly rated” batteries from different
manufacturers have the same baseline. Therefore, to accurately judge the remaining life of a battery it is absolutely
critical to have a recorded baseline for each battery that you use.

The Battery Mhos Reference Chart chart on the back of the BLT displays numbers equating to Mhos readings for
common security industry battery sizes. It is also based on a battery’s ambient temperature being at 72 degrees
fahrenheit. This temperature assumption covers many environmental situations, including cold basements or
unoccupied buildings, since the battery will be kept warm by the recharging and by being inside the electronics
enclosure. However, because cooler temperatures can significantly lower the Mhos reading of a battery, this
instruction manual has a more extensive Mhos chart with columns for evaluating batteries that are being adversely
affected by 62F, 52F, and 42F degree environments. Also see How Temperature affects a Battery

Automatic Shutdown

If the BLT is left connected to a battery for more than 30 seconds after the test is complete, it will automatically shutdown to
conserve battery power. Disconnecting and reconnecting a test lead will restart the test procedure.