Maintenance Free Car Battery Specification Example for Boat Trailers: OEM Replacement
Maintenance Free Car Battery Specification Example for Boat Trailers: OEM Replacement
This is a worked specification for maintenance free car battery in a oem replacement programme. It is the document we would send a buyer who asks what exactly they are getting: the material, the dimensions that are actually controlled, the finish, and the checks that happen before anything is packed.
The oem replacement version exists because the duty cycle on boat trailers is not the same as on a showroom vehicle. Where the two are specified identically, something fails later — usually a fitment that looked right on paper and failed on the bench.

Example specification
| Item | Maintenance Free Car Battery |
|---|---|
| Application | Boat Trailers |
| Version | OEM Replacement |
| Base material | Cast Iron |
| Controlled dimensions | 6 key dimensions, recorded per lot |
| Tolerance band | ±0.2 mm |
| Finish | zinc plated |
| MOQ | 500 pieces per specification |
| Sampling | 7 working days, 3 days per revision |
| Compliance | IATF 16949 |
How the example is built up
- Start from the duty cycle, not from the catalogue photograph.
- Fix the base material in writing — Cast Iron, in this example.
- List the dimensions that are actually controlled and the tolerance on each.
- Name the finish and what it has to survive.
- State the inspection level and who pays when a lot fails.

Processes involved
- sintering
- laser cutting
- heat treatment
- assembly line testing
- CNC machining
- injection moulding
Where this example applies
Programmes that run oem replacement most often specify this build for boat trailers. Related applications include camper conversions, assembly programmes, construction equipment, export programmes, courier fleets.
Checks before packing
- Dimensional report against the approved drawing.
- AQL 4.0 sampling on the finished lot.
- Finish inspection under agreed lighting.
- Carton drop test on the first lot of a new packing specification.
Questions buyers ask
Do you handle mixed containers?
Yes. Most programmes consolidate several part numbers into one container to keep freight sensible at 500 pieces per line.
What happens if a lot fails inspection?
The lot is re-inspected against the golden sample, and replacement pieces ship on the next available booking at our cost.
How long does sampling take?
Samples leave the factory in 7 working days, and each revision round adds about 3 days once you have seen the first piece.
Can the specification be held on file?
Yes. Once approved, the specification is recorded against your part number so a reorder reproduces the IATF 16949-compliant build instead of a fresh interpretation.
Send the specification you are working to and we will confirm what we can match, what we would change and why.



