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2020 RDX Base Model Battery Drains Overnight

0

Mike T. · rep 0 · May 26, 3:56 AM · 1 replies · solved · Question

Vehicle: 2020 Acura RDX Base

My 2020 Acura RDX Base model has been having intermittent battery drain issues. A few times now, I've gone to start it in the morning only to find the battery completely dead. It's not every night, but enough to be a serious annoyance and concern.

I've had the battery tested, and it checks out fine. The alternator also seems to be charging correctly. It feels like something is drawing power even when the car is off. I've noticed some minor electrical quirks too, like the infotainment screen sometimes taking longer to boot up.

Could this be a parasitic draw? What are common culprits in the RDX for this kind of issue? I'm worried about being stranded.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 26, 3:56 AM

0

ClearTheCode admin answer:

Intermittent battery drain in a 2020 Acura RDX, especially when the battery and alternator test fine, strongly suggests a parasitic draw. This means a component is staying active and drawing power even when the vehicle is supposed to be off. The electrical quirks you mentioned can also be a symptom.

  1. Re-test Battery (Load Test): Even if the battery "checks out," ensure it underwent a proper load test. A battery can show good voltage but fail under load, especially if it's nearing the end of its life (typically 3-5 years). Intermittent drains can also prematurely age a battery.
  2. Parasitic Draw Test: This is the primary diagnostic step. It involves using a multimeter to measure current draw from the battery after the car has been off and 'asleep' for about 30 minutes. You then systematically pull fuses one by one until the current draw drops significantly, indicating the circuit with the faulty component. The acceptable draw for modern cars is usually under 50 milliamps (0.05 amps).
  3. Common Culprits in RDX/Acura:
    • Infotainment System/Head Unit: These complex systems can sometimes fail to fully shut down.
    • Hands-Free Link (Bluetooth) Module: A known issue in some Acura models, a faulty HFL module can stay active and drain the battery.
    • Faulty Relays: A relay that sticks in the "on" position can keep a circuit energized.
    • Trunk/Hood/Glove Box Lights: Ensure all interior and compartment lights are turning off when doors are closed. A faulty switch can keep a light on.
    • Aftermarket Accessories: If you have any aftermarket alarms, remote starters, or other electronics, temporarily disconnect them to rule them out.

Causes: Parasitic draw from a faulty module (e.g., infotainment, hands-free link, body control module), a stuck relay, a light not turning off, or an aging battery that struggles to hold a charge.

When to see a shop: Diagnosing a parasitic draw can be time-consuming and requires a good understanding of automotive electrical systems and the proper use of a multimeter. If you're not comfortable with electrical testing, a professional technician can perform a parasitic draw test. They have specialized tools and experience to efficiently trace the source of the drain and recommend the appropriate repair, such as replacing a faulty module or relay. This will prevent repeated dead batteries and potential damage to other electrical components.

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