Antigravity H5 Lithium Battery for Civic Type R & Integra Type S

Antigravity H5 / Group 47 Lithium Battery - Part #AG-H5-40-RS

The factory battery in your FK8 or FL5 Civic Type R is a 35 to 40 lb H5 lead-acid brick bolted to the highest point in the engine bay, right over the front axle. The Antigravity H5 RE-START is the same Group 47 case at 14.25 lb, with 1500 cranking amps and a keyfob that jump-starts the car from the driver's seat. It's the single biggest weight reduction per dollar you can make on a K20C1 car without touching the drivetrain.

What It Is and Why It Works

This is a LiFePO4 pack with a full battery management system inside a 9.5 x 7 x 7.5 inch H5 / LN2 case, the same footprint Honda uses in the Type R, the Integra Type S, and the 11th-gen Civic. It drops into the factory tray, the stock hold-down clamps it, and the stock cables land on the M8x1.25 threaded terminals. No relocation, no fabrication, no cutting the battery sensor off the negative cable.

RE-START is the reason this is a street battery and not a track-day toy. The BMS watches voltage and shuts the pack down before it goes flat, holding back a reserve. Leave the hatch light on overnight and instead of a dead car you press the keyfob (two ship in the box), or the button on the lid, and it starts. The same BMS handles overcharge, short circuit, thermal, and cell balancing, which is why Antigravity backs it with a 5-year warranty instead of the 1-year most race lithium carries.

At 40 Ah actual, this is the capacity you want on a car you drive. Antigravity's 24 Ah H5 is race-only and won't handle a Type R's parasitic draw or a week of sitting. Owners who've run the smaller packs on a daily FK8 report low-voltage gremlins; the ones running the 40 Ah don't.

Specs

Fitment

Every 2017-and-up Civic Type R and every Integra Type S uses the H5 tray, so this is a straight swap. The 2023-and-up Integra 1.5T and the 2022-and-up Civic (Sport, EX, Touring, Si) are also H5 trays, but those cars use an EFB battery and run auto idle stop, which cycles the starter dozens of times per drive. The pack fits physically; confirm with Antigravity before running it on an idle-stop car, or plan on leaving idle stop off. Any 2021-and-earlier Civic or Si, the RSX, the DC2, and the S2000 are Group 51R and need the AG-51R-30-RS, not this.

What to Know Before You Buy

Throw away your lead-acid tender. AGM and flooded chargers run float and desulfation profiles that push past 14.6 V, which voids the warranty and can cook the BMS. If the car sits, use a LiFePO4 charger like the Antigravity SC-4. A stock Type R alternator regulates in the low 14s, so daily driving keeps the pack happy with nothing plugged in.

Use a memory saver when you swap. The Type R and Integra will drop radio presets, window auto-up, and a few adaptive values without one, and the FL5 in particular throws a battery sensor message until it relearns. Leave the sensor on the negative cable and torque the M8 terminals snug, not gorilla-tight; the posts are threaded brass, not lead.

Register it with Antigravity inside 30 days or there is no warranty. Keep both keyfobs; Antigravity won't replace them, and the lid button is your only backup. The Bluetooth tracker that shows state of charge on your phone is sold separately and worth having if the car sees weeks in the garage between drives.

If you run a big amp, a dashcam on constant power, or an aftermarket alarm, chase your parasitic draw before you install this. Lithium doesn't self-discharge the way lead does, but a 200 mA draw will still put the BMS to sleep in a couple of weeks, and repeated deep discharges below 10 V are excluded from warranty.