Gen 2 & Gen 3 Raptor 12V Battery Replacement and BMS Relearn

Who this is for

This applies to both the Gen 2 and Gen 3 Raptor's 12V battery. The video on this page is filmed on a 2018 F-150 5.0 with a 94RH7 AGM battery — not a Raptor specifically, but that's the same Motorcraft BAGM-94RH7-800 spec Ford lists for the Raptor across 2017, 2019 and the Gen 3 2022 manual, so the physical swap carries over directly. We're not describing the video's own BMS reset method here, since it's shown as an alternative rather than Ford's documented procedure; what we give instead is the relearn Ford's own owner's manual describes — an eight-hour sleep window, not a button sequence. Worth understanding before you start: this truck doesn't treat the battery as a dumb box of volts. A battery monitoring sensor sits on the negative cable and tracks current in and out so the charging system knows what state of charge it's working with, which is why Ford documents a relearn at all and why the grounding rule further down exists. There are really three things to finish, not one: the physical swap, the battery management system's state-of-charge relearn, and the engine's own idle and fuel-trim relearn after losing power. Skipping the last two won't break anything permanently, but it's the reason a freshly swapped truck can idle oddly or have features act up for a day and leave an owner convinced they bought a bad battery.

Steps

1. 1

   Watch the intro for what you'll need

   The video's intro chapter runs through the tools and parts it uses before anything comes apart — worth a quick watch to make sure you've got everything staged.

   Jump to 0:00 in the video →
2. 2

   Review what the job actually involves

   This is a two-part job: the physical battery swap, and the BMS relearn afterward. Skipping the second part doesn't damage anything, but it can leave some features temporarily disabled or acting oddly until the system catches up on its own.

   Jump to 0:22 in the video →
3. 3

   Confirm you have the correct battery spec

   Ford lists the same Motorcraft BAGM-94RH7-800 AGM battery for the Raptor across the 2017 and 2019 supplements and the Gen 3 2022 manual. If your truck has Auto-Start-Stop, this matters even more — Ford specifically requires using exactly the same battery specification on those vehicles, not just something with similar numbers on the label.

4. 4

   Set up for the hazard a battery actually is

   A lead-acid battery vents explosive gas, so Ford's own warnings apply here: no flames or sparks anywhere near it, work in a ventilated space rather than a closed garage, and shield your face and eyes. Keep in mind too that some vehicles carry more than one battery — if that's your truck, all of them need disconnecting, not just the one you came for. If you end up only disconnecting the negative cable for some other job, isolate the loose end so it can't fall back onto the post or touch body metal.

5. 5

   Disconnect and remove the old battery

   Disconnect the negative terminal first, then the positive — that order matters for avoiding accidental shorts while you're working with a wrench near grounded metal. Lift the old battery out using a carrier or strap rather than grabbing it by the terminals or case edges alone.

   Jump to 1:08 in the video →
6. 6

   Install the new battery and reconnect

   Set the new battery in place, then reconnect in the reverse order: positive first, negative last. Clean any corrosion off the terminal clamps with a wire brush and a baking-soda-and-water mix before you reconnect if the old terminals looked rough. Put back anything that came off with the old battery — Ford calls out reinstalling the battery cover and the vent hose if your truck has them, and a missing vent hose is an easy thing to leave sitting on the fender and forget.

   Jump to 2:19 in the video →
7. 7

   Relearn the battery management system

   Ford's owner's manual describes an eight-hour relearn: after reconnecting, the vehicle needs eight hours of sleep time — locked, ignition off, left alone — for the BMS to relearn the battery's state of charge. The video on this page shows an alternative method at its BMS Reset chapter; we're not describing that method here, since Ford's documented procedure is the sleep relearn.

   Jump to 3:37 in the video →
8. 8

   Let the truck sit for the full eight hours

   Resist the urge to drive it right away just to "check if it worked." Some features may behave oddly or stay temporarily disabled until the relearn window completes — that's expected, not a sign something's wrong. The window Ford describes is sleep time, not elapsed time, so parking it and then opening a door every ten minutes to check on it isn't the same thing as leaving it locked and alone.

9. 9

   Run the engine's own relearn drive

   Separate from the battery management system, the engine has to relearn its idle and fuel trim after losing power. Ford's procedure for that: apply the parking brake, put it in Park or Neutral with the accessories off, start the engine, let it warm to normal operating temperature, let it idle for at least a minute, then drive at least 10 miles (16 km). Until that's done, a slightly uneven idle or a truck that feels a bit off its usual throttle response is the relearn in progress rather than a fault to go chasing.

10. 10

    Reset the small things that lost power with it

    Disconnecting the battery clears a handful of settings the truck won't restore for you. Ford specifically lists resetting the clock, re-teaching the power windows' bounce-back feature, and re-entering your radio presets. Do these while you're thinking about it — they're the kind of thing you'll otherwise notice in traffic a week later and wonder whether the battery swap caused a real problem.

11. 11

    Never ground accessories to the negative post

    If you're also running aux-switch wiring or any other accessory, don't ground it directly to the battery's negative post — that post feeds the BMS's current sensor, and grounding there throws off its readings. Ground to the chassis instead.

12. 12

    Recycle the old battery

    Take the old battery to a parts store or recycling center that accepts batteries — nearly all do, and most won't charge you for it.

Specs

Safety notes

• Disconnect the negative terminal first, reconnect it last.
• Batteries vent explosive gas — keep flames and sparks away, work somewhere ventilated, and shield your face and eyes.
• Lift the battery by a carrier or by its opposite corners, never by the terminals — squeezing the end walls of the case can force acid out of the vents.
• If battery acid contacts skin or eyes, flush with water for 15 minutes and seek medical attention.
• Never ground accessories directly to the battery's negative post — it feeds the BMS's current sensor.
• On Auto-Start-Stop vehicles, use exactly the same battery specification Ford calls for; don't substitute a similar-looking battery.
• Recycle the old battery; don't put it in regular trash.