A battery that's failing under load can drain overnight or leave you stranded after a short stop. For Kenmore drivers on SR-522 and the Lake Washington loop routes, Tom's B&M Auto load-tests batteries rather than just checking resting voltage — a battery can show 12.6V at rest and fail the moment you turn the key in cold weather. We also test the alternator and starter to make sure the battery isn't a symptom of a bigger charging system problem.
Load test the battery against its rated cold cranking amps. Test alternator charging output at idle and under load. Test starter draw. Inspect battery terminals and cable ends for corrosion and internal damage.
Group-size matched replacement battery installed. For vehicles with battery management systems — most European makes and newer domestics — battery type and capacity programmed into the ECU after installation.
Post-installation charging system test to confirm alternator is charging correctly. Battery terminal protectors applied. Most battery replacements completed in under 30 minutes.
Battery management system registration is the step most shops skip on European and newer domestic vehicles. Without it, the ECU continues charging at the old battery's profile, which shortens the new battery's life significantly. We have the software to perform BMS registration correctly on BMW, Mercedes, Audi, VW, and most domestic vehicles requiring it.
Corroded battery terminals cause the same symptoms as a weak battery — slow cranking, electrical gremlins, parasitic drain. We inspect the terminals and cable ends at every battery service. Surface cleaning isn't enough when corrosion has penetrated the copper strands — we replace cable ends when needed.
Cold cranking amp output tested against battery rating — not just resting voltage.
Battery management system programmed correctly on European and newer vehicles.
Most battery replacements completed in under 30 minutes. Same-day service.
Battery service includes load test against rated CCA, alternator output test, starter draw test, terminal and cable end inspection, group-size matched battery installation, and BMS registration where required.
From Tom's B&M Auto - serving Kenmore and the greater Seattle metro.
Tom's B&M Auto · 17820 Hwy 99, Suite E, Lynnwood · Serving greater Seattle
Also serving: Edmonds, Mountlake Terrace, Shoreline, Mukilteo, Kenmore, Alderwood Manor