Lesson learned: Avoid leaving the OBDII dongle plugged into the LEAF port or it will cause your 12V battery to fail completely.
2018 SL, 22,500 miles. Accidentally left my OBDII (BAFX) plugged in for a month in the vehicle. Vehicle also was not driven for 4 weeks and parked outside in near freezing and normal temperatures. Discovered 12V battery was dead after returning to drive it. Jumped it successfully with my other LEAF, but every time I turned car off, the 12V battery needed jumping again.
I already knew that the OBDII would cause some drain to the 12V battery as even with the car off, the dongle was causing the relays to click every few seconds, thus slowly discharging the battery. Regardless, I replaced the 3.5 year old 12V battery with a new AGM one that was pretty reasonable for $211. Even though my vehicle still has the original Nissan warranty on it (did not buy until mid 2019), the 12V is only covered for 24 months.
Questions:
1. Why does the dongle / LEAF not have ability to keep power off to the port if the vehicle is "off"?
2. I thought the traction battery keeps the 12V battery "topped off" if it falls below a certain power level?
3. Or if #2 is true, is it that the traction battery kept charging the 12V throughout that 4 week interval, but the constant discharge / recharge cycles essentially caused the 12V battery to lose all ability to hold any charge?
2018 SL, 22,500 miles. Accidentally left my OBDII (BAFX) plugged in for a month in the vehicle. Vehicle also was not driven for 4 weeks and parked outside in near freezing and normal temperatures. Discovered 12V battery was dead after returning to drive it. Jumped it successfully with my other LEAF, but every time I turned car off, the 12V battery needed jumping again.
I already knew that the OBDII would cause some drain to the 12V battery as even with the car off, the dongle was causing the relays to click every few seconds, thus slowly discharging the battery. Regardless, I replaced the 3.5 year old 12V battery with a new AGM one that was pretty reasonable for $211. Even though my vehicle still has the original Nissan warranty on it (did not buy until mid 2019), the 12V is only covered for 24 months.
Questions:
1. Why does the dongle / LEAF not have ability to keep power off to the port if the vehicle is "off"?
2. I thought the traction battery keeps the 12V battery "topped off" if it falls below a certain power level?
3. Or if #2 is true, is it that the traction battery kept charging the 12V throughout that 4 week interval, but the constant discharge / recharge cycles essentially caused the 12V battery to lose all ability to hold any charge?
