Testing Batteries Correctly: Systematically Evaluating Voltage, Internal Resistance, Capacity and Electrolyte Density

→ Product: TMC-2001RTS Battery tester → Product: Anton Paar DMA 35

 

A stationary battery system is still operating.

At first glance, the block voltages appear normal.

Does this mean the battery is still in good condition?

Not necessarily.

A single measured parameter can only provide limited information about the condition of a battery.

For a reliable battery diagnosis, different characteristics must be distinguished:

Voltage → electrical operating condition

Internal resistance → changes in the electrical and electrochemical condition

Capacity → actually available energy under defined discharge conditions

Temperature → thermal condition and important influencing factor

Electrolyte density → additional condition indicator for flooded lead-acid batteries

Connector voltage drop → quality of connections under load

The strength of professional battery maintenance therefore lies not in a single measurement, but in combining several test methods and comparing their results over time.

This is exactly what the TMC-2001RTS Battery Tester is designed for.

It combines various test methods within a battery system and enables structured storage and subsequent evaluation of the measured values.

For flooded lead-acid batteries, the diagnosis can additionally be supplemented by electrolyte density measurement. The Anton Paar DMA 35 can be used for this purpose. The recorded density and temperature values can then be assigned to the TMC system and the correct battery installation.

Why is a single battery measurement not sufficient?

Batteries are electrochemical systems.

Their condition therefore cannot be fully described by a single electrical measurement.

Voltage example

A battery block can have an apparently correct voltage during float charging.

However, this does not prove that the block will be able to deliver the required capacity during a subsequent discharge.

Internal resistance example

An unusual resistance value can indicate a change in the battery block.

However, the resistance value is not automatically equivalent to:

remaining capacity in Ah

Electrolyte density example

In a flooded lead-acid battery, the electrolyte density provides additional information about the condition of the electrolyte and the state of charge.

However, it does not replace a controlled capacity test either.

Several diagnostic levels should therefore be combined

Test	Main information provided
Visual inspection	Mechanical condition and obvious damage
Block voltage	Electrical operating condition and differences between blocks
Internal resistance	Changes in battery condition
Capacity test	Actually available capacity under defined load conditions
Temperature	Thermal abnormalities and comparability of measurements
Electrolyte density	Additional diagnosis for flooded lead-acid batteries
Connector voltage drop	Condition of electrical connections under load

Which methods are available for battery testing?

For stationary battery systems, the most important test methods can basically be divided into three groups.

1. Testing during normal operation

These include, for example:

• visual inspection,
• float-charge voltage,
• block voltage,
• temperature,
• internal resistance.

2. Testing under a defined load

These include:

• capacity test,
• discharge curve,
• total voltage,
• discharge current,
• voltage drop across battery connectors.

3. Additional electrochemical testing

For accessible flooded lead-acid batteries, the:

electrolyte density

can additionally be measured.

The methods complement one another

A useful maintenance plan therefore combines:

quick regular condition checks

with:

periodic more detailed testing

1. Visual inspection as the basis

Before connecting test leads, a battery system should first be visually inspected.

Items to check include

• damage to the housing,
• deformation or swelling,
• corrosion on terminals and connectors,
• unusual deposits,
• loose connections,
• leaks,
• unusual heating or discoloration,
• for flooded batteries, also the electrolyte area.

Why is this important?

Electrical measurements cannot completely replace the detection of mechanical defects.

Structured battery maintenance therefore always begins with the overall condition of the system, not just with the first measured value.

2. Measuring block voltage and float-charge voltage

One of the simplest tests is measuring the individual cell or block voltages.

During float charging

the battery is normally permanently connected to the charger.

In this case, not only the absolute voltage is of interest, but above all:

How do the individual blocks differ from one another?

Example

Almost all blocks in a battery system show:

13.55 … 13.62 V

while one block shows:

13.20 V

Such a deviation

should be investigated even if the overall voltage of the battery system initially appears plausible.

TMC-2001RTS – float-charge function

The TMC-2001RTS provides a dedicated function for repeated recording of block voltages during float charging.

This allows, for example:

quarterly comparison measurements

to be systematically assigned to the same battery system.

Important

A correct float-charge voltage primarily shows that the block is currently in a plausible electrical operating condition.

It does not automatically prove sufficient remaining capacity.

3. Measuring internal resistance

Internal resistance measurement is one of the most important methods for recurring condition diagnostics of stationary batteries.

Basic principle

When the current changes, the battery responds with a change in voltage.

In simplified form:

R = ΔU / ΔI

An increasing resistance

can indicate a change in the battery block.

The major advantage

A resistance measurement can be performed much faster than a complete capacity test.

However

The measured resistance should not be interpreted as a direct indication of:

remaining capacity = x %

.

Its particular strength lies in:

condition monitoring and trend analysis

Considering Rel and Rct separately

A special feature of the TMC-2001RTS is the separate assessment of different resistance components.

ICS specifies:

Rel = metallic or electrical resistance component

and:

Rct = charge-transfer resistance

Rel

is more closely associated with the ohmic or conductive components of the battery block.

Rct

describes an electrochemical resistance component of charge transfer within the battery system.

Why is this separation useful?

A simple total internal resistance value can combine several different changes.

If:

Rel

and:

Rct

can be considered separately, the user obtains additional information about which part of the battery behavior has changed.

Important when interpreting the values

A specific fault cause should not automatically be derived from a single Rel or Rct value.

Relevant factors include:

• battery type,
• manufacturer data,
• temperature,
• state of charge,
• age,
• comparison with identical blocks,
• trend compared with previous measurements.

Why Kelvin measurement is important

Battery internal resistances are often in the milliohm range.

At such low resistance values, even:

• test lead resistance,
• contact resistance,
• transition resistance

can significantly influence the measurement result.

Four-wire principle

The TMC-2001RTS uses Kelvin connections for resistance measurement.

This separates the:

current path

from the:

voltage measurement

.

Advantage

The influence of the test leads on resistance determination is significantly reduced.

On the TMC-2001RTS

the following connections are used:

P+ / P-

and:

S+ / S-

Observe safety requirements

A test current is generated during resistance measurement.

The TMC manual therefore points out, among other things, that resistance measurements should not be performed immediately after charging and that the requirements for adequately ventilated battery rooms and permissible hydrogen concentrations must be observed.

For resistance measurement at the P+ input, the maximum permissible block voltage specified in the manual must also be observed.

Why the trend is more important than a single resistance value

A common issue in battery testing is the search for a universal limit value.

For example:

At what mΩ value is a battery considered bad?

There is no universal answer

The normal internal resistance depends, among other things, on:

• battery design,
• rated capacity,
• block voltage,
• manufacturer,
• temperature,
• state of charge.

A reference measurement is therefore particularly valuable

Initial values are recorded for a new or demonstrably intact battery system.

Subsequent measurements are compared with these values.

Example

Initial value:

Rel = 0.80 mΩ

later:

Rel = 0.83 mΩ

and after several years:

Rel = 1.25 mΩ

The change

can be considerably more informative than the absolute value alone.

4. Testing capacity by controlled discharge

If it is necessary to determine how much capacity a battery can actually provide, a controlled discharge is a particularly informative method.

Principle

The fully prepared battery is discharged under defined conditions.

The following parameters are recorded in particular:

• discharge current,
• discharge time,
• total voltage,
• block voltages,
• end voltage.

In simplified form

at constant current:

Capacity Ah = Current A × Time h

Example

A battery supplies:

20 A

for:

4 h

This means:

80 Ah

have been discharged.

In practice

the following parameters specified by the battery manufacturer must also be taken into account:

• discharge rates,
• end voltages,
• temperature conditions,
• evaluation methods.

Advantage of a capacity test

It tests the battery under an actual load.

Disadvantage

The test:

• takes time,
• discharges the battery,
• requires a defined load,
• must be operationally planned.

Therefore

resistance measurement is not a substitute for a capacity test.

Conversely, however, a complete discharge does not necessarily have to be performed during every routine maintenance operation.

Monitoring block voltages during discharge

During a capacity test, not only the total voltage is of interest.

Particularly informative

is the development of each individual block.

Example

The battery consists of:

40 blocks

.

During discharge, 39 blocks behave similarly.

However, one block drops significantly faster.

The total voltage

may still appear acceptable at this point.

However, the individual weak block is already visible.

TMC-2001RTS

The function:

Discharge

allows repeated recording of the individual block voltages during a controlled discharge.

This provides

not only a final value but a:

time-based development of the individual battery blocks

Recording total voltage and discharge current

In addition to the individual block voltages, continuous recording of the complete system is useful during a discharge test.

The TMC-2001RTS provides

Interval U

for recording the total voltage.

In addition

the following function is available:

Interval U+I

.

This allows:

• total battery voltage,
• current signal from a suitable current clamp

to be recorded over defined time intervals.

This allows, for example, documentation of

voltage over time

and:

discharge current over time

Particularly important

when the load is not completely constant.

5. Testing battery connectors under load

A battery system does not consist solely of the battery blocks.

The electrical connections between them are also part of the current path.

A poor connector

can be caused, for example, by:

• a loose connection,
• corrosion,
• contaminated contact surfaces,
• mechanical changes.

Under load

an increased transition resistance causes a voltage drop.

In simplified form:

U = R × I

Example

At:

R = 1 mΩ

and:

I = 100 A

the result is:

U = 100 mV

TMC-2001RTS

provides a dedicated function for recording voltage losses across battery connectors.

The manual recommends performing this measurement in conjunction with a capacity test, because an appropriate battery current is flowing during such a test.

6. Measuring battery temperature

Temperature is not merely an additional secondary parameter in battery diagnostics.

It influences

• electrochemical reactions,
• internal resistance,
• charging voltage,
• available capacity,
• aging behavior.

Resistance values must therefore always be considered in the context of temperature

A comparison between:

Measurement A at 20 °C

and:

Measurement B at 35 °C

can lead to misinterpretations if the temperature is not taken into account.

Local temperature differences

between individual battery blocks can also be diagnostically relevant.

TMC-2001RTS

supports a temperature measurement function using a suitable optional IR temperature sensor.

7. Measuring electrolyte density in flooded lead-acid batteries

For flooded lead-acid batteries with accessible liquid electrolyte, another important diagnostic parameter is available:

electrolyte density

Why does the density change?

In a lead-acid battery, the concentration of sulfuric acid in the electrolyte changes during charging and discharging.

Its density changes accordingly.

In principle

the density can therefore provide information about:

• state of charge,
• differences between individual cells,
• unusual electrolyte conditions.

However

The density must be evaluated in conjunction with:

• temperature,
• battery type,
• manufacturer specifications,
• state of charge,
• where applicable, acid stratification.

Not for sealed VRLA batteries

For:

• AGM batteries,
• gel batteries,
• other sealed battery designs

this type of electrolyte sampling is not intended as part of normal maintenance.

Determining electrolyte density with the Anton Paar DMA 35

Traditionally, acid density was often determined using a:

glass hydrometer

or conventional hydrometer.

A modern alternative

is the:

Anton Paar DMA 35 Standard

ICS specifies the following for the DMA 35, among other things

• density measuring range 0 … 3 g/cm³,
• density accuracy 0.001 g/cm³,
• digital density resolution 0.0001 g/cm³,
• integrated temperature measurement,
• only approximately 2 ml sample volume required,
• H₂SO₄ tables,
• storage of measured values and sample IDs.

Particularly useful for battery maintenance

is the combination of:

Density + Temperature

This means

a density value does not have to be considered independently of the thermal condition.

Practical test procedure

For a flooded lead-acid battery, the electrolyte sample is taken in accordance with the battery and instrument instructions.

The following are then recorded:

• density,
• temperature,
• cell assignment.

Clean working practices are essential

Between measurements, the requirements concerning:

• sampling,
• cleaning,
• prevention of carryover,
• occupational safety when handling sulfuric acid

should be observed.

Transferring measured values from the DMA 35 to the TMC-2001RTS

A major advantage of combining the TMC-2001RTS and DMA 35 is that the density measurement does not have to be maintained as a separate handwritten measurement list.

The ICS product description for the TMC-2001RTS specifies

direct readout of:

DMA35 V3

and:

DMA35 V4

The following values are transferred

• density values,
• temperature values

and assigned to the correct battery system.

This is important

because testing a battery consisting of, for example:

60 individual cells

quickly produces a large number of measured values.

Without digital assignment

the values must manually be:

• written down,
• transferred,
• assigned to the correct cell number.

This creates additional sources of error

such as:

• transposed digits,
• incorrect cell assignment,
• missing temperature values,
• transcription errors.

Direct data transfer reduces this manual intermediate step

and subsequently enables the battery test to be documented as one complete data set.

Reading out DMA35 V3 via IrDA

For the DMA35 V3, the current TMC manual describes data transfer via the integrated:

IrDA interface

The documented procedure is

1. Select the DMA35 (IrDA) function on the TMC-2001RTS.
2. The TMC then waits for data via the infrared interface.
3. Position the DMA35 and TMC approximately 10 cm apart.
4. The infrared transmitter and receiver must be aligned with each other.
5. Export the stored measurement data from the DMA35.
6. The TMC displays the reception status during transfer.
7. After successful transmission, the transferred measured values are evaluated or stored.

For the DMA35 V3, the TMC manual specifies the menu path

Menu → Measuring Data → Export → Export All

.

The following are transferred

Density + Temperature

Advantage

This allows the density measurement to be treated as part of the same documented battery maintenance procedure as:

• block voltage,
• internal resistance,
• temperature,
• discharge data.

DMA35 V4 and Bluetooth

On the current TMC-2001RTS, the measurement menu includes:

DMA35 (IrDA)

as well as:

DMA35 (BT)

.

At the same time, the current ICS product page for the DMA 35 Standard

specifies the following interfaces:

• Bluetooth®,
• RFID.

The TMC product page explicitly specifies

direct readout of:

DMA35 V3 and DMA35 V4

Important for existing instruments

The interface actually used depends on the DMA35 instrument generation and the firmware or instrument version of the TMC-2001RTS.

For an existing combination, the following should therefore be checked before commissioning:

• DMA35 version,
• TMC firmware,
• available DMA35 IrDA or BT menu item,
• intended transmission method.

This prevents

a current DMA35 version, for example, from being configured using instructions intended for an older IrDA instrument generation.

What does electrolyte density actually tell you?

A density value is not a universal good/bad criterion.

The main question to evaluate is

How does one cell behave compared with the other cells?

Example

A battery system has 24 cells.

23 cells show very similar density values.

One cell differs significantly.

The following should then be checked

• is the temperature comparable?
• is the cell fully charged?
• is acid stratification present?
• is the sample representative?
• do voltage or internal resistance also differ?

The combination is particularly important

For example:

Voltage	Resistance	Density	Assessment
normal	normal	normal	no obvious individual indication
deviating	abnormal	abnormal	investigate the cell further
normal	abnormal	normal	check for electrical or electrochemical changes
normal	normal	abnormal	check electrolyte, state of charge and sampling conditions

Which tests are suitable for which battery type?

Test method	Flooded lead-acid battery	AGM / VRLA	Gel / VRLA
Visual inspection	Yes	Yes	Yes
Block voltage	Yes	Yes	Yes
Internal resistance	Yes	Yes	Yes
Capacity test	Yes	Yes	Yes
Temperature	Yes	Yes	Yes
Connector test	Yes	Yes	Yes
Electrolyte density by sampling	With accessible liquid electrolyte	No, not as a regular maintenance method	No, not as a regular maintenance method

Manufacturer specifications remain decisive

The specific maintenance and testing strategy must always be appropriate for the:

• battery design,
• manufacturer approval,
• application,
• safety requirements.

Which method detects which fault?

Observation / fault	Particularly useful test
One block has a deviating float-charge voltage	Block voltage measurement
Condition gradually deteriorates over several years	Internal resistance trend
Actually available battery capacity is unknown	Controlled discharge test
Individual block drops early under load	Block voltages during discharge
Complete discharge curve is to be documented	Interval U or U+I
Connection becomes abnormal under load	Voltage drop across connector
One block shows a thermal abnormality	Temperature measurement
Flooded lead-acid cell may have a deviating state of charge	Electrolyte density with DMA 35
Electrical and electrochemical resistance components are to be differentiated	Rel and Rct measurement with TMC-2001RTS

Recommended test procedure for stationary battery systems

A consistent procedure is particularly important for recurring maintenance.

1. Identify the battery system

Clearly select the location, battery, number of blocks and battery type.

2. Perform a visual inspection

Check the mechanical condition, terminals, connectors and any abnormalities.

3. Measure float-charge voltages

Record all blocks in the same sequence.

4. Measure internal resistance

Record Rel, Rct and block voltage and compare them with previous measurements.

5. Check temperatures

Document unusual temperature differences.

6. Measure electrolyte density for flooded lead-acid batteries

Record density and temperature using the DMA 35.

7. Transfer DMA35 data

Digitally transfer the measured values into the TMC test procedure and assign them to the battery system.

8. Start discharge if a capacity test is scheduled

Record block voltages several times during discharge.

9. Record total voltage and current

Use Interval U+I if required.

10. Measure connectors under load

Record voltage losses across the connections.

11. Transfer results

Then evaluate the measured data in the battery management software.

12. Evaluate the trend rather than a single value

Compare the current measurement with:

• reference values,
• previous maintenance measurements,
• other identical blocks.

Documenting and comparing measured values

One of the main challenges with large battery systems is not the measurement itself.

It is the reliable assignment of the measured values.

Example

A system has:

4 battery strings × 40 blocks

This means that:

160 individual blocks

already have to be managed unambiguously.

If the following are additionally recorded for each block

• voltage,
• Rel,
• Rct,
• temperature,
• density where applicable

several hundred measured values are generated during each maintenance operation.

TMC-2001RTS and CS-Manager

therefore allow work with predefined battery systems and stored measurement data.

ICS also specifies

• transfer of complete battery databases to the TMC,
• RFID support for battery identification,
• graphical and tabular evaluations,
• CSV export,
• report generation.

The real added value comes from the trend

Professional maintenance should not only document:

measured value today

but:

measured value today ↔ measured value 6 months ago ↔ reference value

Typical errors in battery testing

Observation	Possible cause	Recommended check
All block voltages look good	Voltage measurement alone is not sufficient for capacity assessment	Add internal-resistance trend analysis and, if necessary, a capacity test
One block has a significantly higher resistance	Change in block condition	Evaluate Rel/Rct, temperature, voltage and trend together
Resistance values differ from the previous maintenance measurement	Different temperature or state of charge	Compare measurement conditions
Total voltage is correct, but one block drops during discharge	Weak individual block	Monitor block voltages during discharge
Connection becomes hot	Possible increased transition resistance	Check voltage drop across connector under load
Individual flooded cell shows deviating density	State of charge, electrolyte condition or acid stratification	Compare density, temperature, voltage and additional cell values
DMA35 data cannot be transferred as expected	Instrument generation or interface not selected correctly	Check DMA35 version, TMC firmware and IrDA/BT menu
Density values fluctuate unusually strongly	Sampling or carryover	Check measuring cell, sampling procedure and cleaning
Resistance measurement has poor repeatability	Contact at the battery terminals	Check Kelvin contacts and contact surfaces
Capacity test produces an unexpected result	Discharge current, temperature or end voltage not correctly taken into account	Check test conditions and manufacturer data

Practical example: systematically testing a UPS battery system

A stationary UPS has a battery system consisting of several 12-V blocks.

The system is to be assessed as part of scheduled maintenance.

Step 1: Select the battery

The stored battery system is selected in the TMC-2001RTS.

Step 2: Check float charging

The voltages of all blocks are recorded one after another.

One individual block shows a slight deviation.

Step 3: Measure resistance

The following are then determined:

Rel + Rct + block voltage

.

The previously abnormal block also shows a significantly changed resistance compared with the previous maintenance measurement.

Step 4: Compare temperature

It is checked whether the block is thermally abnormal compared with the neighboring batteries.

Step 5: Evaluate the trend

The current data is compared with historical measured values.

For a flooded lead-acid battery, the following would additionally be performed

measurement of the electrolyte density of each relevant cell using the:

Anton Paar DMA 35

The density and temperature values

are subsequently transferred into the TMC test procedure.

Step 6: Capacity test

If a capacity test is required based on the maintenance plan or identified abnormalities, the battery is discharged in a controlled manner.

The following are documented:

• block voltages,
• total voltage,
• discharge current,
• connector losses where applicable.

Result

The decision regarding continued operation of the battery block is not based on a single value, but on the combination of voltage, resistance behavior, temperature, electrolyte density where applicable, discharge behavior and historical trend.

Suitable ICS products for professional battery testing

TMC-2001RTS – Mobile Battery Tester

The central system for this test procedure is the:

TMC-2001RTS

ICS specifies, among other things

• measurement of the metallic resistance Rel,
• measurement of the charge-transfer resistance Rct,
• block voltage measurement,
• total voltage measurement up to 600 V DC,
• float-charge testing,
• charge and discharge measurements,
• temperature measurement with optional IR sensor,
• measurement of connector voltage losses,
• interval recording of voltage,
• interval recording of voltage and current,
• connection of DMA35 density meters,
• RFID for battery identification,
• Bluetooth interface,
• extensive measurement data storage.

Particularly for recurring maintenance

the combination of:

standardized procedure + unambiguous battery assignment + stored measured values + trend analysis

is decisive.

Anton Paar DMA 35 Standard

For flooded lead-acid batteries with accessible electrolyte, the:

Anton Paar DMA 35 Standard

supplements the electrical test with direct density measurement.

ICS specifies

• density 0 … 3 g/cm³,
• density accuracy 0.001 g/cm³,
• temperature measurement,
• H₂SO₄ tables,
• 2 ml sample volume,
• measurement memory,
• sample IDs,
• Bluetooth® and RFID.

The combination is particularly useful for

• UPS maintenance,
• stationary battery systems,
• power supply systems,
• telecommunications systems,
• emergency power systems,
• industrial batteries,
• recurring service work.

Which test with which instrument?

Task	Suitable solution
Block voltage during float charging	TMC-2001RTS
Measure Rel and Rct	TMC-2001RTS
Document capacity test	TMC-2001RTS in combination with a suitable discharge setup
Record total voltage over time	TMC-2001RTS Interval U
Record total voltage and current	TMC-2001RTS Interval U+I with suitable current clamp
Connector voltage drop under load	TMC-2001RTS
Battery temperature	TMC-2001RTS with suitable temperature sensor
Electrolyte density of flooded lead-acid batteries	Anton Paar DMA 35
Transfer density and temperature values into battery documentation	DMA 35 + TMC-2001RTS
Historical evaluation and reports	TMC-2001RTS + CS-Manager

Additional instruments can be found under Battery Testers / Battery Testing Instruments / Density Meters at ICS Schneider.

Conclusion

Professional battery testing does not consist of a single measurement.

Voltage only shows one part of the battery condition

A plausible block voltage does not automatically prove that a battery still has the required capacity.

Internal resistance is highly suitable for trend diagnostics

With the TMC-2001RTS:

Rel

and:

Rct

can be considered separately.

The capacity test checks the battery under load

Block voltages, total voltage and discharge current show how the battery actually behaves during discharge.

The connectors are also part of the battery system

Voltage drops across the connections can indicate increased transition resistance under load.

Temperature is part of every reliable assessment

It influences both the electrical and electrochemical behavior of the battery.

For flooded lead-acid batteries, electrolyte density is an additional parameter

With the Anton Paar DMA 35, density and temperature can be measured directly on site.

Data integration is particularly useful

The density and temperature values can be assigned to the TMC-2001RTS and the corresponding battery system.

This turns several individual measurements into one coherent maintenance data set

consisting of:

Voltage + Rel + Rct + Temperature + Density + Discharge data + Connector values

For practical applications

Clearly identify the battery system → perform visual inspection → record float-charge voltages → measure Rel and Rct → document temperatures → for flooded lead-acid batteries, measure electrolyte density with the DMA 35 → transfer density and temperature data to the TMC → compare measured values with previous tests → perform capacity test if required → monitor block voltages during discharge → record total voltage and current → test connectors under load → document results in CS-Manager → evaluate trends rather than individual limit values.

FAQ: Battery Testing with TMC-2001RTS and DMA 35

Which methods are available for testing a battery?

Typical methods include visual inspection, voltage measurement, internal resistance measurement, temperature measurement, controlled capacity testing and – for flooded lead-acid batteries – electrolyte density measurement.

Is battery voltage sufficient to assess battery condition?

No. A normal voltage does not automatically mean that a battery still has the required capacity.

What does the internal resistance of a battery indicate?

It is an important indicator of changes in the battery block. The trend compared with previous measurements and similar blocks is particularly informative.

Can remaining capacity be calculated directly from internal resistance?

Not reliably as a general direct conversion. Resistance measurement and capacity testing provide different information.

What does the TMC-2001RTS measure for internal resistance?

The TMC-2001RTS enables separate consideration of the metallic or electrical resistance component Rel and the charge-transfer resistance Rct.

What is Rel?

Rel refers to the more strongly ohmic or metallic resistance component of the battery block.

What is Rct?

Rct is the charge-transfer resistance and describes an electrochemical component of charge transfer.

Why is separating Rel and Rct useful?

Because changes in different resistance components can be observed in a more differentiated manner than with a single combined internal resistance value.

Why should internal resistance be measured regularly?

Recurring measurements enable trend analysis and can reveal gradual changes.

What is Kelvin measurement?

In Kelvin or four-wire measurement, the current and voltage measuring paths are separated. This reduces the influence of test leads and contact resistance when measuring very low resistances.

Can the TMC-2001RTS measure block voltage?

Yes. The instrument supports measurement of individual block voltages and provides dedicated functions for float charging, charging and discharging, for example.

Can the TMC-2001RTS measure total voltage?

Yes. ICS specifies total voltage measurement up to 600 V DC.

Can the TMC-2001RTS perform a capacity test?

The TMC-2001RTS supports structured recording and documentation of the relevant voltage and current values during a controlled discharge. The required discharge load or actual load setup must be provided separately according to the battery test.

What is the difference between an internal resistance test and a capacity test?

Resistance measurement provides a quick condition diagnosis. A capacity test, by contrast, determines how much capacity the battery can actually supply under defined discharge conditions.

Why are individual block voltages measured during a capacity test?

This allows weak individual blocks to be detected before the total voltage of the battery system becomes critical.

Can the TMC-2001RTS record a discharge curve?

Yes. The interval functions can record voltage profiles and, with suitable current measurement, both voltage and current over time.

What is Interval U?

This TMC function is used for time-based recording of a voltage, for example the total voltage during a discharge.

What is Interval U+I?

It allows the total voltage and the output signal of a suitable current clamp to be recorded simultaneously over defined time intervals.

Why should battery connectors be tested?

Increased transition resistance at connectors can lead to voltage losses and heating under high load.

How does the TMC-2001RTS test battery connectors?

The voltage drop across the connector is recorded under load. The manual recommends this test in conjunction with a capacity test.

Why is battery temperature important?

Temperature influences internal resistance, electrochemical processes, available capacity and aging. Measured values should therefore be evaluated under conditions that are as comparable as possible.

Can the electrolyte density of a battery be measured?

Yes, for flooded lead-acid batteries with accessible liquid electrolyte.

Why is the acid density of a lead-acid battery measured?

The electrolyte density provides additional information about the condition and state of charge of a flooded lead-acid battery cell.

Is electrolyte density equivalent to battery capacity?

No. Density measurement is an additional diagnostic method and does not replace a defined capacity test.

Can density be measured in AGM batteries?

Regular electrolyte sampling is not intended for sealed AGM/VRLA batteries.

Can density be measured in gel batteries?

No, not as a conventional maintenance method. The electrolyte is immobilized and the system is sealed.

What is the Anton Paar DMA 35?

The DMA 35 is a portable digital density and concentration meter.

What density measuring range does the DMA 35 have?

ICS specifies 0 to 3 g/cm³.

What density accuracy does ICS specify for the DMA 35?

ICS specifies 0.001 g/cm³ under the stated measurement conditions.

Does the DMA 35 also measure temperature?

Yes. In addition to density, the sample temperature is also recorded.

Can the DMA 35 measure sulfuric acid?

Yes. ICS lists H₂SO₄ tables among the supported measured quantities.

How much sample does the DMA 35 require?

ICS specifies a sample volume of approximately 2 ml.

Can the DMA 35 be connected to the TMC-2001RTS?

Yes. The TMC product page specifies direct transfer of data from DMA35 V3 and DMA35 V4.

Which data is transferred from the DMA 35 to the TMC?

Density and temperature values are transferred and assigned to the corresponding battery system.

How is the DMA35 V3 connected to the TMC?

For the DMA35 V3, the TMC manual documents data transfer via IrDA.

How far apart should the DMA35 V3 and TMC be for IrDA transfer?

The TMC manual specifies approximately 10 cm. The transmitter and receiver of the infrared interfaces must be aligned with each other.

Which TMC menu item is used for IrDA transfer?

The corresponding menu item is DMA35 (IrDA).

Does the TMC also have a DMA35 Bluetooth menu item?

Yes. The current TMC manual additionally shows the DMA35 (BT) menu item.

Which interfaces does ICS specify for the current DMA 35 Standard?

ICS specifies Bluetooth® and RFID.

Why should the DMA35 version be checked before pairing?

Because the available interfaces may differ between instrument generations. The DMA35 version, TMC firmware and intended transmission method should therefore be compatible.

What is the advantage of direct data transfer?

Manual transcription is largely eliminated. This reduces the risk of transposed digits and incorrect assignment of individual cell values.

Can the TMC-2001RTS store battery systems?

Yes. Complete battery definitions or battery databases can be transferred to the instrument.

Does the TMC-2001RTS support RFID?

Yes. RFID can be used to identify or select stored battery systems.

Which software is used for evaluation?

CS-Manager is available for the TMC-2001RTS for managing and evaluating battery measurement data.

Can reports be generated?

Yes. ICS specifies graphical and tabular evaluations, CSV export and report functions.

What is particularly important for recurring battery tests?

Measurement conditions should be as consistent as possible, battery blocks must be clearly assigned, and current measured values should be compared with historical reference values.

Which measurement is the most important?

There is no single measurement that provides all information about battery condition. The most reliable diagnosis results from combining several test methods.

Where can I find the TMC-2001RTS at ICS Schneider?

Further information can be found under TMC-2001RTS Mobile Battery Tester at ICS Schneider.

Where can I find the Anton Paar DMA 35 at ICS Schneider?

Further information can be found under Anton Paar DMA 35 Standard at ICS Schneider.

Where can I find additional battery testing instruments at ICS Schneider?

An overview can be found under Battery Testers / Battery Testing Instruments / Density Meters at ICS Schneider.