Quick answer: Battery Replacement on a 2016–2020 Kia Optima is rated Easy and takes about 30-90 minutes. You'll need 2 tools for this job, and parts cost about $180. This guide walks you through the full job step by step, including the mistakes to avoid.
| Part Name |
Part Number |
Price |
Buy |
| Replacement 12-volt battery for 2016-2020 Kia Optima; verify group size, CCA, terminal layout, and VIN fitment |
— |
$180.00 |
|
| Anti-corrosion terminal protectant or felt washers (optional) Optional |
— |
$8.00 |
|
About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.
💡 Pro tip: Order all parts at once to save on shipping
Step-by-Step Instructions
Follow these steps carefully
1
Verify battery fitment and charging symptoms
Confirm fitment for your 2016-2020 Kia Optima by engine before buying, because the size varies: the 2.4L and 1.6L gasoline models commonly take a Group 94R/H7 AGM (about 800 CCA), while the 2.0L takes a Group 48 battery — so check the label on the battery in your tray rather than guessing. AGM is the right choice for this generation, especially with the available Idle Stop & Go system. (Hybrid Optima models carry their 12-volt battery in a different location — check your owner's manual if you have a hybrid.) Watch for slow cranking, dim lights, start-stop that quits, or a battery warning, and get a free battery and alternator test at a parts store first, since a weak charging system mimics a bad battery.
🔧 Mechanic's note — Tom Becker
The 2.0L's Group 48 versus everyone else's 94R/H7 is the ordering trap on the Optima — same model, different tray size. I read the label on the old battery, not the website's 'most common fitment.'
2
Make the vehicle safe
Park level, shift to Park, set the parking brake, ignition fully off. The battery is under the hood in a tray with a hold-down. Wear gloves and eye protection; remove metal jewelry.
3
Disconnect the old battery
If a plastic cover blocks the terminals, pop it off. Loosen the negative (black) clamp first (typically 10 mm), twist it off the post, and tuck it away. Then remove the positive (red) clamp.
4
Seat the battery and reconnect
Seat it flat and refit the hold-down snugly. Reconnect positive first, then negative, tightening each clamp until it won't twist on the post. Clean corrosion with a wire brush and apply dielectric grease.
🔧 Mechanic's note — Ray Delgado
Positive first on, negative first off — I say it as a chant because reversing it is how wrenches weld themselves to the fender. Every battery job I do follows that order without thinking.
5
Reset and verify operation
Start and confirm brisk cranking with no warning lights. Take a 15–20 minute drive and confirm Idle Stop & Go resumes once the computer is satisfied. Recheck terminals and the hold-down. Return the old battery for the core refund — never trash a lead-acid battery.
All Done!
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
- • Buying by appearance instead of group size, CCA, polarity, and hold-down fit
- • Shorting the positive terminal to the body with a metal tool
- • Lifting the battery by damaged terminals or leaving it unsecured
- • Skipping battery registration, window/clock resets, or charging-system checks when required
- • Assuming a new battery fixes a parasitic draw or charging fault
