Konnwei BK100 Bluetooth 12 Volt Battery Analyzer for Android/iOS

The BK100 uses conductance testing, so a battery can usually be checked while fitted to the vehicle and without applying the heavy external load used by an old-style carbon-pile tester. It is powered from the battery being tested and does not need charging or internal batteries.

For a useful result, the battery construction, rating standard and rated value printed on the battery label must be entered correctly. Selecting the wrong battery type or entering the wrong CCA figure can make a healthy battery appear weak or a weak battery appear acceptable.

Best Suited For

The BK100 suits home users, mobile mechanics and workshops wanting an inexpensive tester for cars, motorcycles, boats, caravans and other equipment using compatible 6V or 12V lead-acid batteries. It is particularly convenient when the user is comfortable viewing results on a phone rather than a separate tester screen.

Understanding the Battery Result

A battery can show normal resting voltage and still be unable to supply enough current to start the engine. The measured CCA and internal resistance help identify this type of failure.

A low state of charge does not automatically mean the battery needs replacement. The battery may simply be discharged because the vehicle has not been used, an electrical load was left on or the charging system is not maintaining it. Charge the battery fully and retest before replacing it unless the tester identifies a clear internal failure.

A Replace result should be checked against the battery label and selected rating standard. Entering a 600 CCA battery as 800 CCA will make the result look worse than it really is.

Cranking-System Test

The cranking test records the voltage drop while the starter motor turns the engine and the duration of the cranking event. This helps assess whether the battery remains strong enough under starting load.

A large voltage drop can be caused by a weak battery, excessive starter current, poor battery-terminal contact, damaged cables or mechanical resistance in the engine. The battery-health result and physical cable condition should be considered before blaming the starter motor.

A vehicle that does not crank at all may require further voltage-drop and current testing with other equipment.

Charging-System Test

With the engine running, the app can check charging voltage and help identify undercharging or overcharging. The test may also guide the user through checking the system with electrical loads switched on.

Low charging voltage can result from an alternator fault, slipping drive belt, poor wiring connection or an intelligent charging system that is deliberately reducing output. High voltage can damage the battery and vehicle electronics.

Modern smart-charging vehicles can vary alternator voltage according to temperature, battery condition and electrical demand. Results on these vehicles should be interpreted alongside the manufacturer’s charging strategy rather than using one fixed voltage rule.

Battery Rating Standards

The BK100 supports common standards including CCA, BCI, CA, MCA, JIS, DIN, IEC, EN and SAE. Select the same standard shown on the battery label and enter the printed rating.

The listed test range is 100 to 2000 CCA for the relevant standards, with corresponding ranges for JIS, DIN and IEC batteries.

App Display and Test Records

The free Konnwei app provides the display, instructions and results. It can show battery data in a more spacious format than a small handheld tester and may retain or share test records from the phone.

The app language normally follows the phone’s language setting. The exact app layout can change as Konnwei releases updates.

Basic Test Procedure

1. Switch the vehicle and electrical loads off.
2. Connect the red clamp to battery positive and the black clamp to battery negative.
3. Open the Konnwei battery-testing app and connect to the BK100.
4. Select whether the battery is installed in the vehicle.
5. Select the correct battery construction and rating standard.
6. Enter the rating printed on the battery label.
7. Run the battery test, then follow the app instructions for cranking and charging tests if required.

Good clamp contact is important. Dirty, loose or corroded terminals can produce an unreliable result, so connect to clean metal and retest if the reading appears inconsistent.