Why does my Suzuki Wagon R battery drain overnight even after recent replacement?

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Why does my Suzuki Wagon R battery drain overnight even after recent replacement?

I recently installed a new battery in my 2018 Suzuki Wagon R, but it still gets completely drained if the car is left overnight. I always make sure the lights and AC are off before turning the car off. What could be causing this power loss? Could there be a parasitic drain from aftermarket accessories like the tracker, sound system, o r internal wiring fault?

Gari Specialist asked on 24 May 2025 16:52:37 pm

1 Answer

10 views |

Gari Master - on 24 May 2025 16:55:20 pm

If your battery drains overnight even after installing a new one, the issue is likely a parasitic drain – something is drawing power from the battery when the car is off.

Common Causes:

Aftermarket tracker, sound system, o r dash cam staying powered 24/7

Faulty relay, ECU, o r immobilizer that doesn’t shut off completely

Old o r weak alternator diode allowing reverse current flow

Interior lights o r trunk light not turning off due to switch issues

What You Should Do:

Have an electrician check for parasitic draw using an ammeter. A healthy idle draw should be less than 0.05A.

Pull fuses one by one to identify which system is draining the battery.

If the tracker is the cause, have it wired correctly to turn off with ignition.

Tip: Always check if any lights like glove box o r trunk light are staying on unnoticed.