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Compact black 12 V battery tester with pivoting LCD display and cigarette lighter plug

TN TONNY TN4 12V Car Battery Tester LCD 80g

SKU CH-85Y5-69WF7 MPN TN4

Plugs into a 12 V cigarette lighter to show battery voltage and alternator charging status on an LCD bar graph

  • Team affiliation1 Piece
  • Key featuresBattery Powered, false
  • Overall height5.4 L x 1.1 W x 2.5 H inches
  • Overall width5.4 L x 1.1 W x 2.5 H inches
  • Overall length5.4 L x 1.1 W x 2.5 H inches
  • Product weight80 g
  • Plugs into 12 V cigarette lighter for instant battery and alternator health check
  • LCD shows measured voltage with bar-graph charge-level indicator
  • Pivoting head adjusts for clear reading without shifter interference
  • Pocket-sized 5.4 x 1.1 x 2.5 inch body weighs only 80 grams
  • One-year manufacturer guarantee backs the TN4 tester

What this product is

The TN TONNY TN4 is a pocket-sized 12 V battery and charging-system tester that plugs directly into a vehicle’s DC cigarette-lighter socket. It weighs 80 grams and measures 5.4 x 1.1 x 2.5 inches. An LCD shows measured voltage with a bar-graph charge-level indicator, and a pivoting head lets the driver adjust the viewing angle.

Who this suits and who should look elsewhere

Suits owners of 12 V passenger cars who want a quick, no-tools health check of the battery and alternator from inside the cabin. Not for technicians needing load-test data or internal-resistance figures. Not for users whose vehicles lack a 12 V DC lighter plug or who require measurements on commercial-vehicle electrical systems.

The specification that decides fit

The tester operates only from a 12 V DC cigarette-lighter plug, so the vehicle must provide that socket and voltage. If the vehicle uses a different socket type or system voltage, the unit cannot connect or read correctly.

How it compares

Measured against everything we stock in Multimeters & Electrical Testers, at today’s prices. Recalculated every night.

Price $25.99
Cheaper than about 60% of the 971 comparable items (median $30.99).

Specifications

Product
Brand nameTN TONNY
Product typeBattery Tester
Size & build
Overall height5.4 L x 1.1 W x 2.5 H inches
Overall width5.4 L x 1.1 W x 2.5 H inches
Overall length5.4 L x 1.1 W x 2.5 H inches
Product weight80 g
More details
Team affiliation1 Piece

Questions about this item

How long can the TN4 stay plugged into the 12 V socket before the battery drains?

The tester draws power only while displaying readings; it does not charge or discharge the vehicle battery.

Does the TN4 become hot or make noise during continuous monitoring?

The unit has no fan or moving parts, so it runs silently and stays at ambient temperature.

What must the vehicle already have for the TN4 to work?

A working DC 12 V cigarette-lighter socket is required for the plug-in connection.

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