How Chinese Factories Handle Overseas Battery Warranty (and How to Win a Claim)

A warranty printed on the quote means nothing if the terms are vague. Most overseas disputes we see are not about a bad cell — they are about a clause nobody read before the container left. Here is what to lock down.

What a real warranty covers

Standard LiFePO4 terms run 5 to 10 years with end-of-term capacity retention of 80 percent or more and 3,000 to 6,000 cycles. The cycle number is meaningless without the depth-of-discharge it was tested at: 6,000 cycles at 80 percent DoD and 6,000 at 100 percent DoD are different products. Require the DoD in writing. The cell grade behind the claim is in our Grade A vs B cell guide.

The clauses that void it

Read the void list before you pay. Common voids: paralleling more packs than rated, operating outside 0-50°C, a non-listed inverter, water or impact damage, and any self-repaired BMS. A "lifetime warranty" with no DoD and no void list is a red flag, not a benefit. Verification discipline is part of factory verification.

The claim process that actually works

When a pack fails overseas: submit the batch report, serial number, and site photos; run a capacity (discharge) test to confirm the Ah delivered; then settle by third-party lab or return-to-factory per the terms. The argument is always about the test method, so specify it in the PO up front. Certification context is in our battery certifications guide.

Lock it in before the container leaves

Commission a pre-shipment sample test at a third-party lab, keep the batch report in every box (we do), and write DoD, cycle count, and the verification method into the purchase order. That paperwork is what converts a denied claim into a replacement. The full nine-question buyer checklist is in our factory verification guide.

Frequently asked questions

What does a standard LiFePO4 warranty cover?

Typical terms are 5 to 10 years with capacity retention of 80 percent or more at end of term and 3,000 to 6,000 cycles. The cycle count is only meaningful with the depth-of-discharge it was tested at.

What voids a battery warranty?

Common voids: paralleling more packs than rated, operating outside 0-50°C, a non-listed inverter, water or physical damage, and self-repaired BMS. A 'lifetime warranty' with no DoD is a red flag.

How do I file an overseas warranty claim?

Submit the batch report, serial, and photos; run a capacity test; then use a third-party lab or return-to-factory per the terms. Specify the verification method in the PO.

How do I avoid warranty disputes before shipping?

Commission a pre-shipment sample test at a third-party lab, keep the batch report in every box, and write DoD, cycle count, and verification method into the purchase order.