The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2018 CR-V Touring - Battery keeps dying overnight, possible parasitic draw?

0

Dan C. · rep 0 · May 22, 2:45 AM · 1 replies · solved · Question

Vehicle: 2018 Honda CR-V Touring

My 2018 Honda CR-V Touring has been having a persistent issue where the battery drains completely overnight. I've replaced the battery twice in the last six months, thinking it was just a bad battery, but the problem keeps coming back.

It starts fine after a jump, but if I leave it parked for more than 8-10 hours, it's dead again. I've checked for obvious things like lights left on, but everything seems off. Could this be a parasitic draw? What should I be looking for?

It's really frustrating having to jump-start my car every morning. Any tips on how to diagnose this at home before I take it to a shop?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 22, 2:45 AM

0

ClearTheCode admin answer:

This sounds like a classic case of a parasitic draw, where an electrical component continues to consume power even when the vehicle is off. Diagnosing this can be tricky but is often solvable.

1. Confirm the Draw:

  • Charge your battery fully. Disconnect the negative battery terminal and connect a multimeter in series between the negative battery post and the negative battery cable. Set the multimeter to measure amperage (mA or A). A normal draw is usually under 50mA (0.05A) after the car has 'gone to sleep' (which can take 15-30 minutes after locking).

2. Isolate the Circuit:

  • Once you confirm a high draw, start pulling fuses one by one from the under-hood and interior fuse boxes. Watch the multimeter reading. When the amperage drops significantly, you've found the circuit with the draw.

3. Common Causes:

  • Aftermarket Accessories: Anything added after purchase (remote start, alarm, stereo) is a common culprit.
  • HVAC Blower Motor Resistor: Can sometimes stay partially active.
  • Infotainment System/Head Unit: A module that fails to power down correctly.
  • Door/Trunk Switches: A faulty switch might keep a light on or a module awake, thinking a door is ajar.
  • Relays: A stuck relay can keep a circuit energized.

When to See a Shop:

  • If you can't isolate the circuit or the draw is from a critical system (e.g., engine control module, body control module), professional diagnosis is recommended. A shop can use more advanced diagnostic tools to pinpoint the exact component causing the issue. They can also check for software updates that might resolve module sleep issues. Ignoring a parasitic draw will continue to shorten your battery's lifespan and leave you stranded.
Menu

Help & account