The replacement clock
The replacement feels like a new purchase — new box, new part, sometimes a new receipt line. The warranty clock disagrees, and how much it disagrees depends on the chain. This page is the table the counters don't keep.
| Chain | Replacement clock — as published |
|---|---|
| AutoZone (batteries) | The replacement battery's warranty runs from the original purchase date. No restart. The free window and the proration window are both measured from battery #1. |
| O'Reilly | The replacement is covered for 90 days or the remainder of the original warranty period, whichever is greater. A floor under every exchange. |
| Advance | No replacement-clock rule found in the published general terms this site verified — the claim runs on the original receipt's period. Flagged as unverified (see the correction log); ask for the rule in writing if a counter states one. |
| NAPA | Per-line documents govern; no general replacement-clock rule in the verified record. Flagged as unverified; the tag process and the store's own paperwork decide. |
Sources: the chains' published warranty documents (see each chain page), checked Oct 20, 2026. Unverified cells are labeled unverified here and in the checker — never filled with a plausible-sounding rule.
At AutoZone, a late-window battery replacement is worth less than it feels — price your decisions (and your proration math) off the original date. At O'Reilly, never let a replacement leave the store undocumented: the 90-day floor runs from the exchange, so the exchange paperwork is a warranty document. Keep it like one.
Not sure which wall you hit? The free checker sorts it in a few picks — chain, part, purchase date, your proof, and the store's own words — and gives you where you stand under the written policy, the proration math where it applies, the exact next counter move, and the ladder above the store. Run the checker →
The pages above are the map. The kit is the paperwork: the word-for-word counter scripts, the per-chain playbooks, the worksheets, and the complaint templates.
One payment, yours to keep. You do every step yourself — at the store, on the phone, in writing; we never call a store for you. See everything inside the kit →