Business account service · Alternator or battery?
Alternator Or Battery? On-Site Testing in Shirley
Not sure if it is the battery or the alternator in Shirley? We test both under load before recommending anything. Mobile fleet jumpstart across B90.
The two faults feel identical from the driver's seat and cost very different amounts to fix. The distinguishing test takes about ninety seconds with the engine running, which is why nobody should be guessing.
Fleets working out of the B90 area — courier, plumbing, electrical, HVAC, roofing, letting agents — call us daily. We know your vans, we know your yard, we know when your first drop is.
Account customers get priority slots ahead of retail callouts, so a fleet job on your yard in Shirley won't sit behind three domestic driveway jobs.
Who needs this test
Anyone in Shirley who has been told "it's the battery" twice and is not convinced.
Domestically, 1930s semis and retail-park units dominate around here, which shapes how these jobs are accessed and worked.
How the two faults present
Drivers doing longer runs from Shirley toward Solihull notice charging faults sooner, because the warning light shows up mid-journey.
Locally that means the streets between Shirley and Solihull, with access via M42 J4/J5 and A34 Stratford Road and a practical radius reaching Solihull (~2 mi) and Shirley (~2 mi).
Jumped and died again?
That is a charging symptom. We test the alternator under real electrical load before anyone mentions a new battery. We route in via M42 J4/J5, roughly 2 miles out from Solihull.
Charging faults found nearby
Recent job nearby: a vehicle in Shirley jumped four times in a week. Charging voltage 12.7V at 2,000rpm with lights on — alternator, not battery, and the owner stopped throwing money at parts.
Recent job nearby: a car near Solihull with an intermittent battery light. Ripple test showed a failed diode; the battery itself tested perfectly.
The readings that separate them
- Belt condition and tension are inspected, since a glazed belt slipping under load mimics a failing alternator.
- Ripple voltage is checked for failed diodes in the rectifier pack, which can charge adequately but destroy a battery over months.
- Parasitic drain diagnostics standard — trackers, dashcams, refrigeration, tail-lifts, aftermarket wiring
- Fleet & Business Jumpstart work here is judged against the vehicle's own specification rather than a generic pass mark.
How the visit runs
- 1
Onboard the fleet
One call, one fleet list, account live the same day for first callouts.
- 2
Driver calls in
Driver quotes the fleet reference; no card payment, no per-job admin.
- 3
The readings that separate them
Engine-running voltage should sit roughly between 13.8V and 14.7V — below 13.2V under load is a charging fault regardless of how new the battery is.
- 4
Priority dispatch
Account jobs go ahead of retail callouts, typical arrival 30–45 minutes.
Local reference data — Shirley
- Postcode districts
- B90
- Reference point
- Sears Retail Park
- Page focus
- Alternator or battery?
- County
- West Midlands
- Area type
- Neighbourhood
- Local commercial context
- aerospace and airport services
Areas we test in
Working out from B90, the practical radius for a fleet jumpstart takes in Solihull, Shirley, Olton and Knowle — all within a few minutes of M42 J4/J5.
Alternator vs battery questions
Q.Do you do preventative fleet audits?
Yes — quarterly on-site checks: voltage, load test, alternator output, terminal condition on every vehicle. Reports emailed to your fleet manager.
Q.The car started on jump leads and then died. What does that mean?
Classic charging fault. The engine ran on borrowed energy and stopped when the battery could no longer supply the ignition system.
Q.Can a bad alternator ruin a new battery?
Yes, in both directions. Undercharging sulphates the plates; overcharging boils off electrolyte. Both shorten life dramatically.
Q.Do you replace alternators too?
We diagnose them on-site and can replace batteries on the spot. Alternator replacement is a workshop job, and we will tell you exactly what needs doing so you are not paying for diagnosis twice.
Q.Do you cover Shirley and the B90 area for this?
Yes. Shirley is inside our routine coverage from Oldbury via M42 J4/J5, roughly 2 miles from Solihull. We cover it alongside Solihull and the surrounding streets.
Q.Can drivers call directly?
Yes — we tag your account against your fleet's registered numbers so drivers don't need to authorise every call, and admin still sees one invoice.
Why this is safe to book
- Diagnosis is given in numbers — resting voltage, charging voltage and ripple — not adjectives.
- Old batteries removed and recycled on every fleet jumpstart.
Related pages
- Car Jumpstart — alternator or battery? in Shirley
- Van Jumpstart — alternator or battery? in Shirley
- Workplace and staff parking — fleet jumpstart in Shirley
- Motorhome and leisure vehicles — fleet jumpstart in Shirley
- Driveway and home callout — fleet jumpstart in Shirley
- Alternator or battery? in Solihull (~2 mi)
- Alternator or battery? in Shirley (~2 mi)
- Alternator or battery? in Olton (~2 mi)
- Alternator or battery? across Solihull
- Fleet & Business Jumpstart in Shirley — main page
- All jumpstart services in Shirley
The short version
Storage fault or supply fault — the tests are different, the costs are different, and guessing is expensive. Every visit here includes the charging check. Locally this is handled alongside Solihull and Shirley, so the van is rarely far away.
Stranded with a flat battery?
Call now or send a WhatsApp — we'll confirm your quote and dispatch the nearest engineer.