The iPhone 15 Pro Max carries a 4,441 mAh cell, the largest Apple has shipped in an iPhone, and it is already the single most requested battery job for shops serving business users. This walkthrough reflects what actually happens on the bench, including the two steps most shops skip and later regret.
What You Need Before Starting
| Item | Specification | Shop Note |
|---|---|---|
| Replacement battery | 4,441 mAh rated, matched flex | Confirm the flex connector matches 15 Pro Max, not 15 Pro (4,383 mAh) |
| Adhesive strips | Battery stretch adhesive | Order 2 sets per job; the first strip often tears |
| Display assembly opening | Heat plate + suction + pick set | The 15 series display seals are firmer than 13/14 |
| Security screws | Pentalobe P2 + internal pentalobe | Keep the bottom screws with the customer ticket |
Step-by-Step Workflow
Step 1 - Discharge to 25-30%. A nearly full lithium cell is a fire risk if you nick it. Ask the customer or drain it with a stress test before opening.
Step 2 - Open from the bottom edge. Heat the lower perimeter to about 80 C, pull the suction cup, and work a pick around. The 15 Pro Max adhesive is continuous, so move slowly near the corners where the panel flexes most.
Step 3 - Display off, battery disconnect first. Remove the pentalobe bracket over the battery connector before touching anything else. On this generation Apple moved the connector slightly compared to the 14 Pro Max; do not muscle the old position.
Step 4 - Pull the adhesive strips. Stretch slowly at a low angle. If a strip snaps, use a few drops of isopropyl under the cell and a plastic card - never metal pry tools against a pouch cell.
Step 5 - Fit and seal. Lay new adhesive, seat the cell, connect battery, test boot, then close the display. Run a 10-minute functional check: charging, speakers, Face ID, and cameras before handing the phone back.
Step 6 - Health data. Aftermarket cells on the 15 series show an Unknown Part message. If your workflow includes a transfer/programmer tool, pair the health data; otherwise explain the message to the customer up front so it does not become a comeback.
Common Shop Mistakes on This Model
- Reusing stretched adhesive to save 30 seconds - the cell shifts and the phone comes back with creaking.
- Forgetting the speaker mesh transfer: dust gets into the new cell cavity and causes rattling complaints.
- Quoting the 15 Pro battery price for a 15 Pro Max job - different capacity, different part cost.
Stock the matching cells in our batteries collection and model-specific kits under for iPhone 15 Pro Max. For sealant and adhesive consumables, see flex cables and small parts.
FAQ
How long does the job take? An experienced tech runs 35-45 minutes including reseal and testing.
Will the customer see an Unknown Part warning? With unpaired aftermarket cells, yes. It is informational and does not affect performance; pair health data if you offer that service.
What warranty should we give? Most shops offer 6-12 months on cells with a cycle-count note in the invoice.