Hi PaPaSteve,
I have been running my 2011 Leaf for six years now and love it. An original Japanese car with the white interior. I too have had the 12volt battery problems and seem to have a handle on it now.
Normal car batteries are designed to provide high cranking current then recharge immediately. They degrade quickly if standing for a few days with less than full charge. One of the side effects is a voltage drop when a sudden heavy load is put on thwe12v battery. A momentary heavy load, such as the 380v battery relays switching on startup, A/C compressor starting, etc cause a sudden voltage drop for a second or less and trip spurious alarms/error codes.
The Leaf draws the lead acid battery down just while standing. If it gets too low for too long the plates will sulphate and the battery will not hold a charge, so voltage drops quickly = Lots of spurious error codes. A cheap battery may not last a year if the car is regularly left standing for four or five days at a time. I know!
During the Covid lockdowns I was only using the car once a week. Towards the end of the first lockdown I found I was getting stupid problems and then the car would not switch on unless I charged the 12v battery after only 36 hours. The ebay bargain "Snappy" brand I replaced it with only lasted eight weeks. The next one lasted one year using the car two or three times a week.
If left for more than four days make sure 12v battery is fully charged and then disconnect it. I have left my 2011 Leaf for eight weeks and it was fine. Did not have to charge 12v when I got home and it started when battery reconnected.
Best battery 12v battery for an electric car is a semi-deep cycle AGM battery which will not degrade when standing for longer periods with less than full charge.
I have been running an Optima D51R yellow top for 18 months. The battery fits straight into the battery carrier. I find I need to start the car every five days to top it up as the onboard systems (smart key and 2G link to Nissan) do draw it down. If I ever have to replace it I will alter the battery carrier to fit the biggest Optima yellow top possible in the space.
https://www.optimabatteries.com/sea...Batteries&from=0&size=99&sort=1&sortType=DESC
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Two other things that might help...
Firstly unplug the dongle from the OBD port when you are not using it. It uses about 7x the power the car uses when switched off.
The other draw is the TCU.
In the UK the car TCU automatically downloads data to Nissan through the 2G mobile phone network. Unfortunately I live in an area of poor cover 2G is lousy and is now being discontinued. It seemed that the car would try to connect and keep trying even after it was switched off. I have now removed the unit. I can not be sure if that has improved 12v battery life as I did it the same time I fitted the Optima. I have no alarms or warnings apart from one line on Leafspy.
I understand this will also disable Carwings. No loss as I was never able to use Carwings anyhow as it was registered to the first owner, who died, and I got no help from Nissan or the RAC who ran the system in the UK when I tried to re-register it. (It doesn't seem to be much good anyway.)
Instructions on how to disconnect/remove the TCU here:- https://mynissanleaf.com/threads/tcu-disconnect-service.25949/
--------------------------------------
There is a whole thread about 12v battery problems here:- https://mynissanleaf.com/threads/dead-12v-battery-question.18258/
I hope this is of interest and wish you good luck. Em
I have been running my 2011 Leaf for six years now and love it. An original Japanese car with the white interior. I too have had the 12volt battery problems and seem to have a handle on it now.
Normal car batteries are designed to provide high cranking current then recharge immediately. They degrade quickly if standing for a few days with less than full charge. One of the side effects is a voltage drop when a sudden heavy load is put on thwe12v battery. A momentary heavy load, such as the 380v battery relays switching on startup, A/C compressor starting, etc cause a sudden voltage drop for a second or less and trip spurious alarms/error codes.
The Leaf draws the lead acid battery down just while standing. If it gets too low for too long the plates will sulphate and the battery will not hold a charge, so voltage drops quickly = Lots of spurious error codes. A cheap battery may not last a year if the car is regularly left standing for four or five days at a time. I know!
During the Covid lockdowns I was only using the car once a week. Towards the end of the first lockdown I found I was getting stupid problems and then the car would not switch on unless I charged the 12v battery after only 36 hours. The ebay bargain "Snappy" brand I replaced it with only lasted eight weeks. The next one lasted one year using the car two or three times a week.
If left for more than four days make sure 12v battery is fully charged and then disconnect it. I have left my 2011 Leaf for eight weeks and it was fine. Did not have to charge 12v when I got home and it started when battery reconnected.
Best battery 12v battery for an electric car is a semi-deep cycle AGM battery which will not degrade when standing for longer periods with less than full charge.
I have been running an Optima D51R yellow top for 18 months. The battery fits straight into the battery carrier. I find I need to start the car every five days to top it up as the onboard systems (smart key and 2G link to Nissan) do draw it down. If I ever have to replace it I will alter the battery carrier to fit the biggest Optima yellow top possible in the space.
https://www.optimabatteries.com/sea...Batteries&from=0&size=99&sort=1&sortType=DESC
-------------------------------------
Two other things that might help...
Firstly unplug the dongle from the OBD port when you are not using it. It uses about 7x the power the car uses when switched off.
The other draw is the TCU.
In the UK the car TCU automatically downloads data to Nissan through the 2G mobile phone network. Unfortunately I live in an area of poor cover 2G is lousy and is now being discontinued. It seemed that the car would try to connect and keep trying even after it was switched off. I have now removed the unit. I can not be sure if that has improved 12v battery life as I did it the same time I fitted the Optima. I have no alarms or warnings apart from one line on Leafspy.
I understand this will also disable Carwings. No loss as I was never able to use Carwings anyhow as it was registered to the first owner, who died, and I got no help from Nissan or the RAC who ran the system in the UK when I tried to re-register it. (It doesn't seem to be much good anyway.)
Instructions on how to disconnect/remove the TCU here:- https://mynissanleaf.com/threads/tcu-disconnect-service.25949/
--------------------------------------
There is a whole thread about 12v battery problems here:- https://mynissanleaf.com/threads/dead-12v-battery-question.18258/
I hope this is of interest and wish you good luck. Em
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