The comparisons between digital battery tester and traditional load tester are as below:

• Easy to use interface.
• No heat problem.
• Available to perform serial tests.
• Test multiple lead acid battery builds including AGM flat plate, AGM spiral and Start-Stop.
• Test both charged and discharged batteries down to 1.5V.
• Test based on SAE, DIN, EN, IEC & JIS international battery industry ratings, under the operation temperature at 30℉~122℉/0℃~50℃.
• Fast diagnosis in 2 seconds, DHC testers show recommended actions.
• Double your battery and electrical business just by making a simple, minutes test part of your daily inspection routine.

The comparisons between digital battery tester and traditional load tester are as below:

• Size: DHC digital battery testers are more compact and much more lighter than traditional ones.
• Measurement time: traditional battery tester takes 10-15 sec to do the measurement, while DHC digital battery tester takes only 2 sec to complete the measurement.
• Continuous using: DHC digital battery tester allows continuous using, and the function remains in good conditions.
• Restriction: Traditional battery tester can only be used when the tested battery is fully charged, however, the DHC digital battery tester has no restriction on the measurement.

By using the technology we developed, which is proved by worldwide Car OEs and Battery OEs, DHC digital battery testers are capable of telling results from SOC & SOH. Besides, DHC digital battery testers will also give the suggestions such as

• Good & pass: The battery is good.
• Good & recharge:The battery is good but needs to be recharged.
• Caution:The battery may be serviceable but with decreased capability to start the engine. The battery might fail under extreme climate conditions. Please pay attention to the battery for possible replacement and charging system analysis. Possible reasons are:
  • For flooded battery, the electrolyte is below the line or the battery is leaking electrolyte because of the broken container.
  • The battery cannot hold a charge because of the sulfuric acid crystal on the plates.
  • The positive/negative plates or the separators are damaged or shedding. The battery is getting old.
• Recharge & retest: The battery is discharged. Please recharge it and retest. Possible reason is:
  • The battery has not been used for a long time. To not misjudge the battery, please recharge it and retest. If the result is still “Recharge and retest” after the charging, the battery should be replaced since it cannot hold a charge.
• Bad & replace: The battery cannot hold a charge. Please replace it. Possible reasons are:
  • The battery cannot hold a charge because of the sulfuric acid crystal on the plates.
  • The positive/negative plates or the separators are damaged or shedding.
  • The battery is getting old (overcharged or over discharged).
• Bad cell & replace: The battery has at least one cell short-circuited. Please replace it. Possible reason is:
  • The positive/negative plates or the separators are damaged or shedding. The short circuit is because of the sediment.

1. SOC: The percentage of the tested battery is actually charged.
2. SOH: The capacity of the tested battery is left (%) comparing with the marked original battery capacity.

1. Normal: The alternator functions well.
2. Low: The alternator cannot provide sufficient current to the battery.
   1. Check the belts to ensure the alternator is rotating with engine. Please replace the belt if it is slipping or broken.
   2. Check the connections from the alternator to the battery. Please clean or replace the cable if the connections are loose or heavily corroded.
   3. Please replace the alternator if the belt and connections are all in good condition.
   4. High: The voltage output from the alternator exceeds the limits of a functioning regulator . Check to ensure there is no loose connection and the ground connection is normal. Please replace the regulator if there is no connection issue. Since most alternators have the regulator built inside, the alternator will need to be replaced as well.
3. Normal : Diode functions well in the alternator / stator.
4. High: It means one or more diodes in the alternator are not functioning or there is starter damage. Check to ensure the alternator mounting is sturdy and that the belts are in good shape and functioning properly. If the mounting and belts are good, please replace the alternator.
5. No ripple detected: Diode functions well in the alternator / stator.

• Normal: The charging system is showing normal output from the alternator. No problem detected.
• Low: The alternator cannot provide sufficient current for the system’s electrical loads and the charging current for the battery.
  • Check the belts to ensure the alternator is rotating with engine. Please replace the belt if it is slipping or broken.
  • Check the connections from the alternator to the battery. Please clean or replace the cable if the connections are loose or heavily corroded.
  • Please replace the alternator if the belt and connections are all in good condition.
• High: The output of the alternator from the battery exceeds the normal limit of a functioning regulator. Check to ensure there is no loose connection and the ground connection is normal. Please replace the regulator if there is no connection issue. Since most alternators have the regulator built inside, the alternator will need to be replaced as well.

Correct functioning of the engine depends on many factors like correct sensor readings and proper functioning actuators.
The Engine itself also needs to be in good condition.
It is essential to the running of the engine that it has sufficient compression.

The compression provided by the rising piston is determined by the ratio of two volumes: the volume swept by the cylinder as it compresses, and the volume remaining in the combustion chamber at top-dead-center. This ratio is called the compression ratio.

The compression is also determined by the effectiveness of the seal between the cylinder's wall and the piston, and this seal is maintained by the piston rings.

The same applies to the seating of both the inlet and exhaust valves. Piston rings are made of centrifugally spun cast iron, which produces a radial pressure forming the seal. Cast iron is also used for its excellent self-lubricating properties.

Compression Ratio = Cylinder Volume divided by Chamber Volume.

A typical compression is between 120 and 200 psi.

1. An ineffective seal between the cylinder and the piston.
2. Poor seating of the inlet and exhaust valves.
3. Broken or seized piston rings.
4. Incorrect camshaft timing.
5. An obstructed induction tract.

1. Carbon build-up within the combustion chamber. (reducing its volume)
2. Excessive 'skimming' of the cylinder head.
3. Incorrect thickness of the head gasket.

Checking the actual cylinder compression on the vehicle in a traditional way is not an easy task.

The technician needs to disable the fuel system, remove the plastic cover above the engine, remove the coils and then unplug the sparks, before the cylinder compression gauge could access to the cylinder.

Plus, a common cylinder compression gauge could only measure one cylinder at a time.

In other words, it takes four individual compression test on a four-cylinder engine by cranking and measuring 4 times to get the measurement for all 4 cylinders.

It has higher labor cost and is time consuming.

The alternative way for testing the cylinders on a vehicle is called, “Relative compression ratio test” The principle of the relative compression test is based on tracking the battery current/voltage changes during cranking to determine the compression values of all cylinders.

Analysis of the current/voltage changes gives the comparative compression values of all cylinders. An engine with poor compression in one or more cylinders can be quickly identified using the relative compression test, and with the relative compression test you can easily determine whether all cylinders have about the same compression.

The relative compression analysis does not measure the actual pressure, but just compares one cylinder to the next. Hence the term "relative“.

DHC is using the voltage analysis method as it’s the most user-friendly way of conducting a test. The better the compression, the lower the voltage, and vice versa.

1. Quick test to confirm if there are significant engine mechanical issues or not.
2. All cylinders can be tested at once.
3. No pressure sensors are needed to check each cylinder.
4. No need to remove spark plugs, glow plugs, injectors or disconnect spark plug leads.
5. Suitable for any vehicle, regardless of manufacturer or vehicle types.
6. Suitable for gasoline and diesel engines.
7. Irrespective of the number of cylinders. (up to 12)

1. Make sure the battery OCV is above 12.6V.
2. Disable the fuel system by removing the fuse of the fuel pump or injection.
3. Clamp BT24XX onto the battery and select “Relative Compression Ratio”.
4. Select number of cylinders and start the test.
5. Crank the engine for approx. 5 seconds and apply full throttle during cranking attempt. (Engine will not be started since the fuel system is disabled.)
6. Check the test result on the display of BT24XX.

It is as simple as conducting a battery test!