OptiMate TEST – Cranking & Alternator

MSRP $44.95

12V tester for battery state of charge, cranking performance and vehicle charging system.

The ultimate pocket tester for on-vehicle battery performance & alternator voltage testing with either 12V lead-acid or 12.8V LiFePO4 starter battery – Easy troubleshooting from cranking to charging!

  • For vehicles fitted with 12V AGM, GEL and STD lead-acid or 12.8V LFP / LiFePO4 starter battery.
  • As easy as 1-2-3, connect to battery, check state of charge, start engine tester displays cranking voltage and vehicle charge voltage simultaneously – 15 sec is all you need!
  • Display cranking volts down to 6V and charge voltage range up to 15V – Check weak battery or overcharging!
  • Easy to use! Connect with the included clips to the battery or connect to an installed SAE battery lead.






SKU: TS-121 Category:


MSRP = Manufacturer Recommended Retail Pricing. Price in EURO and GBP include VAT of 20%. VAT in your region may differ. Price in USD and CAD do not include sales tax.


SKU: TS-121
MSRP USD $39.90

SKU: TS-121
MSRP CAD $60.49

SKU: TS-120
MSRP EUR €39.90

SKU: TS-120
MSRP GBP £37.99


Easy to use! Connect clips to the battery or connect to an installed SAE battery lead, then:

  • Check battery charge level. A low battery cranks (starts engine) poorly.
  • Start engine. OptiMate TEST records and indicates (for 20 sec) the lowest start volts.
  • With engine running, verify charging voltage from alternator and voltage regulator.

TIP: Low charge voltage causes poor battery performance. Too high charge voltage causes excessive gassing and will eventually damage a lead-acid battery. Too high charge voltage is FATAL for a LiFePO4 starter battery!

LENGTH: 40″/100cm

CHARGE CONNECTOR (INPUT): 2-pin SAE (+set batteryclips)

OPERATION:  fully automatic

  • State of charge result in GREEN / RED LED resuls, indication of lowest start Volts when engine starts (20 sec) and running voltage from alternator & voltage regulator.

CABLE RATING: SPT-2W 16 AWG (1.32mm2)

FUSE: No fuse

USE: -40°C/-40°F very low temperature, remains flexible at ‘below freezing’ temperatures

STYLE: Fully enclosed electronic circuitry with multiple LEDs, SAE charge connector

WARRANTY: 3-year limited replacement warranty