Traction Battery completely drained

[dzimmerm56]

My Wife reported our 2016 Nissan Leaf would not start. It was reporting battery extremely low and asked if I wanted to find a charger. Since I was at home and have a level 2 charger in the back driveway the problem was how to get the car to the back driveway from the front yard where it was currently parked, AND, what happened, as the leaf had about 67% charge when we left it in the front the day before.

I had read that the 12 volt battery can sometimes cause problems so I checked it. To all appearances the battery was ok, reading about 12.5 volts. I decided to try hooking up a 12 volt battery charger to the 12 volt battery to see if the car would allow movement. That did not seem to help much. I then hooked up the level 1 trickle charger that came with our leaf.

The car acted oddly, with the charge indicator lights. The passenger side charge light did blink, very weakly, and the driver side charge light blinked quite a bit. A little owners manual research indicated the passenger side light was indicating main battery charging and the drivers side light indicated 12 volt battery charging. This convinced me the 12 volt battery was not working correctly. I purchased a replacement at Sam's Club, a Type 51R battery. Replacement was fairly simple with removal of the hold down and then removing the negative lead and then the positive lead. The hold downs and the lead clamps were all 10mm nuts .

I had previously cleaned the terminals after finding a small amount of corrosion on the positive terminal. That did not change the symptoms but did mean I did not need to clean the lead again while installing the new battery.

I let the trickle charger run for about an hour, after which is still showed the battery completely flat, BUT, it did allow me to put the car in drive. I carefully put everything in order and then drove the car around to the back of my house and hooked it up to the 3.3KW Level 2 charger I have installed in the back. After charging for about an hour and a half I went back and checked and the battery was now showing 29% charged. I breathed a sigh of relief.

As far as I know, the battery I removed was an original equipment battery so was at least 5 years old. I decided to keep the battery, rather than returning the core, as it may be useful in other uses once I rejuvenate it.

I thought my experience might prove helpful to others who have Leafs with 5 year old 12 volt batteries.

My Wife and I really love our Leaf and this was the first time it has caused an issue where it did not get up where we needed to go.

 

[SageBrush]

This may be a case of the traction battery discharging trying to keep the 12v charged.
Better keep an eye on it in case you have an underlying problem that was just band-aided with a new 12v. The traction battery should pretty much keep its SoC overnight unless there is a current leak or a load.

 

[Stanton]

I thought my experience might prove helpful to others who have Leafs with 5 year old 12 volt batteries.

This was really the only thing I needed to read.
I don't understand why anyone (especially an EV owner) would allow a 12v battery to go 5 years without replacement...but that's just me. Caveat: this is for lead acid and not Lithium. My LiFePO4 battery is over 7 years old...during which time I probably would have gone through 3 lead acid batteries.
I'm glad your Leaf is back to normal.

 

[DaveinOlyWA]

This may be a case of the traction battery discharging trying to keep the 12v charged.
Better keep an eye on it in case you have an underlying problem that was just band-aided with a new 12v. The traction battery should pretty much keep its SoC overnight

Too much weird info to make any real conclusions other than the 12 volt needed a boost which is quite...normal. Even leaving the car on with A/C running all night wouldn't drain away 67% of the pack? A key piece of data is missing here.

 

[SageBrush]

Even leaving the car on with A/C running all night wouldn't drain away 67% of the pack?

Arithmetic awaits you

 

[goldbrick]

Assuming the SOC numbers are correct - and I think that's an if due to the 12V failure - a lot of energy went somewhere overnight. Since the car wasn't moving it must have been converted to heat. Something must have gotten pretty warm if that much power from the traction battery was consumed while the car was just sitting there.

 

[jjeff]

Possibly the car mistakenly left ON? Easy to do on a Leaf that is totally silent even when on......note to drain the battery that fast you'd think the heater would have to have been on also, which is hard to believe in our hot summer.

 

[Nubo]

Possibly the car mistakenly left ON? Easy to do on a Leaf that is totally silent even when on......note to drain the battery that fast you'd think the heater would have to have been on also, which is hard to believe in our hot summer.

I'd lean more towards this. Ran the traction pack down and then drew the 12V flat when the dc/dc converter could no longer charge it.

 

[Nubo]

I thought my experience might prove helpful to others who have Leafs with 5 year old 12 volt batteries.

This was really the only thing I needed to read.
I don't understand why anyone (especially an EV owner) would allow a 12v battery to go 5 years without replacement...but that's just me. Caveat: this is for lead acid and not Lithium. My LiFePO4 battery is over 7 years old...during which time I probably would have gone through 3 lead acid batteries.
I'm glad your Leaf is back to normal.

Mine (Bosch platinum AGM) is going on 6 years and still passing a load test. But I'll certainly replace it when it starts testing weak.