Solutions to 12 Volt Batteries and Chargers Posted Here

[QueenBee]

So pluging in my 12 volt charger is kind of a pain. My OpenEVSE has a cordset that has the extra wire for proximity. I'm thinking if I extend a 12 volt cable to the charge hatch. Then rewire the proximity wire in the handle with a 12 volt pigtail that'll plug in to the connector now under the hatch. Then on the EVSE side connect the proximity wire to another pigtail that I can plug my 12 volt charger into. Then I can charge the 12 volt battery by simply connecting the pigtail on the handle and hatch when I'm plugging in to charge.

This is similar to what I did. I ran the SAE plug to the charging port on the car side. I have a Battery Tender with a 12 foot SAE extension hanging right near the evse line from above. It hangs to just above the floor if I let it go and is just to the left of the garage door. Then I can just swing it over, plug it in at the charge port and its good to go. Then unplug it and let it swing away and it hangs back out of the way. No more opening the hood or cords dragging on the floor.

But it is making me think of simply electrical taping the SAE line to the evse line, then it would be right there as well. But then again I don't always need the 12v line there.

That's a great idea. I think I'll start with that and can move to using the proximity wire later if I like it.

[Marktm]

Update.
Fully charged the 12 volt battery with the ~1 amp desulfator/charger several days ago. "Equalized" at 16 volts for a couple of hours. Battery at near 100 % SOC => 12.8 volts. After a couple of days of "normal" driving (one long trip with QC, many short trips and recharges), the battery is right back to ~60% SOC => 12.37 volts. Seems inherent to the design!

Do the 2015/16 have these same issues?

[BrockWI]

Ok, I thought I had fixed my problem by putting a larger 12v battery in the car last fall. This spring I have had it dead twice now. The only thing that changed was me going back to 80% charging. So maybe the longer time sitting at the top end of charging or that last few percent give the 12v battery a longer time to fully recharge (more absorb time?) Also since I have a '13 with the 80% option and charge at the higher rate (6kw) often I am charging from 40 to 80 in summer, so about 90 minutes, where in winter 20 to 100 takes at least 4 hours, granted the last 30+ minutes are balancing, but that it still a longer time to charge the aux battery.

So I wonder if this issue is more prevalent with folks with 6kw charger (that charges faster) or if it even exist with folks that charge primarily via 120vac?

[RegGuheert]

After a couple of days of "normal" driving (one long trip with QC, many short trips and recharges), the battery is right back to ~60% SOC => 12.37 volts.

Did you let the car sit for an hour or so without opening the doors (like to pop the hood)? If you took the measurement right after popping the hood, then this is about the voltage I would expect with the car loading the battery.

[dhanson865]

Update.
Fully charged the 12 volt battery with the ~1 amp desulfator/charger several days ago. "Equalized" at 16 volts for a couple of hours. Battery at near 100 % SOC => 12.8 volts. After a couple of days of "normal" driving (one long trip with QC, many short trips and recharges), the battery is right back to ~60% SOC => 12.37 volts. Seems inherent to the design!

Do the 2015/16 have these same issues?

Do you use your windshield wipers often?

That's the trick that gets the car to charge the 12v. At the start of your trip spray a little wiper fluid and let the wipers run a cycle then turn them off. The leaf will charge the 12v quicker for the next few minutes anticipating that you'll use the wipers more. Assuming you don't it just charged the 12v more.

[Marktm]

Did you let the car sit for an hour or so without opening the doors (like to pop the hood)? If you took the measurement right after popping the hood, then this is about the voltage I would expect with the car loading the battery.

I have monitored the voltage on many many occasions - even with the battery disconnected and "settled". It seems to range between 12.3 to 12.4. After an extended "trickle" charge it does go to the 12.7+, but after any "normal" driving situation of several days, it settles back to the lower voltage ~60% SOC best as I can tell. Based on the work done at the start of this post - understanding the charging voltages, it all makes sense. IMHO, the NIssan engineers (for a 2012 at least) designed for a 70% + SOC "normally" to prevent too much sulfation and knowing that the 12 volt battery loading is mostly minimal, the high quality battery would last OK! I did confirm that mine is the original battery - almost 4 years old, so probably a reasonable balance of low 12 volt energy use and longevity of the battery. Again IMO - certainly welcome any other opinions! Any Nissan engineers want to chime in?

I'm going to try and find a used Northstar Blue 40 AH telcom battery and try it - cannot afford a new one!

BTW, The "wiper" use likely is way too short to do any significant charging - again IMO! We have had plenty of rain here in South East Texas!!!

[DaveinOlyWA]

your voltage is "normal" or at least in line with my observations over 2 cars. I generally check a few times to see a range so I will check immediately after driving/charging then 30 mins then an hour and a few hours after that.

Mine also settles into the 12.3 12.4 range most of the time

[QueenBee]

So pluging in my 12 volt charger is kind of a pain. My OpenEVSE has a cordset that has the extra wire for proximity. I'm thinking if I extend a 12 volt cable to the charge hatch. Then rewire the proximity wire in the handle with a 12 volt pigtail that'll plug in to the connector now under the hatch. Then on the EVSE side connect the proximity wire to another pigtail that I can plug my 12 volt charger into. Then I can charge the 12 volt battery by simply connecting the pigtail on the handle and hatch when I'm plugging in to charge.

This is similar to what I did. I ran the SAE plug to the charging port on the car side. I have a Battery Tender with a 12 foot SAE extension hanging right near the evse line from above. It hangs to just above the floor if I let it go and is just to the left of the garage door. Then I can just swing it over, plug it in at the charge port and its good to go. Then unplug it and let it swing away and it hangs back out of the way. No more opening the hood or cords dragging on the floor.

But it is making me think of simply electrical taping the SAE line to the evse line, then it would be right there as well. But then again I don't always need the 12v line there.

That's a great idea. I think I'll start with that and can move to using the proximity wire later if I like it.

I installed one of these under the charge port cover right below the DCQC port. So far working well as far as ease of use. I am concerned that it's not going to last a long time as in that position it has filled up with water when it rains and it doesn't drain it self. Not sure exactly why that happened, it may just been from the cap not staying shut as it's a bit difficult to get on all the way or from raining while having the cord plugged in.

https://www.amazon.com/gp/product/B0031 ... UTF8&psc=1 looks like it's gone up $5.

[Cor]

Has anybody seen their Leaf keep the battery at 14.4V and the 3rd charging light blinking for over 9 hours long (car not plugged in)?
I am a bit worried about the aux battery being cooked to death with such high voltage for so long, while it is pretty warm today (28degC = 82 degF) as well as my main battery getting depleted, only 3 bars left (20 mi range) and the DC/DC is humming along and the waterpumps pushing water around for cooling - all coming from the main battery from noon till 9PM so I am concerned what I will find tomorrow morning - dead main battery?
My Leaf is a 2012 that had a warranty battery replacement earlier this year (so, SW upgrades have been done)
and also needed a new 12V battery a month later.
Now again a few months later I have used the car very little until this last week, since then I have driven it almost every day, charged several times and last time was Friday night/Sat morning charged to 100% and moved the car around a bit but not really driven it any distance.
Parked the car in garage Sat night and Sunday noon time noticed the 3rd blue charging indicator blinking and soft humming (water pump) coming from car. Checked if any of the timers were active, but no climate or other timers present, so I measured the aux battery and found it to be held at 14.4V
I have searched but could not find anyone mention how long the 3rd charging light would remain blinking and 12V battery being charged without the car being plugged in. 9 hours seems to be an excessive time, especially since at the beginning of the weekend the car was charged.
Any ideas?
Seeing the history of battery failure earlier this year, could there be a malfunction that causes the car to keep charging?
As far as I know the Over-the-Air telecommunication module was not upgraded, so no Carwings should be active (no remote climate control)
Any help appreciated.

[Cor]

This morning, the 3rd light was still blinking and the car had lost another 12 miles of range overnight (12 hrs), so I plugged it in and will visit the dealer later today.
I noticed that when I plug it in to charge, the aux battery voltage goes to 13.10V. When I unplug, the 3rd LED starts blinking again and the aux battery voltage goes to 14.42V. Totally weird.