PianoAl
Posts: 217
Joined: Mon May 16, 2016 4:15 pm
Delivery Date: 20 May 2016

12V Battery Questions

Mon Jan 02, 2017 7:50 pm

Our Leaf had been driven on Saturday, plugged in Saturday night. Not used and now, Monday evening I started up LeafSpy Pro, and saw that the 12V battery was at 11.96V.

Q 1. That sound reasonable?

Q 2. How much SOC will I lose per day of non-operation?

Q 3. What's the highest SOC at which you would consider topping off?

Q 4. Let's say the Leaf is left plugged in, and the SOC begins dropping. At what point will it top off on its own (if ever)?

Thanks!
2016 Nissan LEAF Model S, Purchased May 2016

baustin
Posts: 372
Joined: Tue Feb 24, 2015 1:23 pm
Delivery Date: 09 Mar 2015
Leaf Number: 402162
Location: North Las Vegas, NV

Re: 12V Battery Questions

Tue Jan 03, 2017 5:08 am

Based on what I've read here over the last two years, that reading is somewhat expected. It can be affected by other factors.

Did you leave the bluetooth OBD adapter turned on?

Did the vehicle do a charge cycle anytime from when it was plugged in Saturday until you checked it on Monday?

Do you have the charge or climate timers activated?

Have you checked the cells on the 12 volt battery to see if they need topped off (use only distilled water)?

Is it cold where you are (near freezing or below)?

Is the vehicle parked in a garage or outside?

SOC is generally used to refer to the charge level of the traction battery, not the 12 volt battery. If the vehicle is sitting parked, the SOC of the traction battery should change very little under normal conditions. There is a heater that will kick in if the traction battery gets too cold, and it will charge up the 12 volt battery if the voltage level gets too low. The Leaf will not automatically charge the traction battery, unless the charging timer is active.

I would try to avoid letting the SOC of the traction battery fall below 20%. How often you charge it should depend on how often you drive it. Don't let it sit at 100% for more than a few hours, if at all possible, especially in high heat conditions. I've had to make changes to my charging patterns as my battery has degraded (now 3 bars down). Currently, the charge timer runs every morning at 2am, to 100% on weekdays and 80% on weekends.
2013 Leaf SV - Cayenne Red - QC Port - LED Headlights

PianoAl
Posts: 217
Joined: Mon May 16, 2016 4:15 pm
Delivery Date: 20 May 2016

Re: 12V Battery Questions

Tue Jan 03, 2017 6:15 pm

Thanks.

>Did you leave the bluetooth OBD adapter turned on?
No, I switch it off.

>Did the vehicle do a charge cycle anytime from when it was plugged in Saturday until you checked it on Monday?
No.

>Do you have the charge or climate timers activated?
No

>Have you checked the cells on the 12 volt battery to see if they need topped off (use only distilled water)?
No

>Is it cold where you are (near freezing or below)?
No. Around 45 degrees F.

>Is the vehicle parked in a garage or outside?
Inside.
2016 Nissan LEAF Model S, Purchased May 2016

baustin
Posts: 372
Joined: Tue Feb 24, 2015 1:23 pm
Delivery Date: 09 Mar 2015
Leaf Number: 402162
Location: North Las Vegas, NV

Re: 12V Battery Questions

Wed Jan 04, 2017 3:46 am

The 12 volt battery is charged whenever the traction battery is charged. It also kicks in when the windshield wipers are turned on. There are some minor loads that never turn off, like the radio memory and clocks. I would periodically check the cell levels, and top off as needed. Otherwise, don't worry over it until you start getting odd behaviors or the car won't turn on.

It is warm enough that the battery heater should not be turning on. You should see little or no change in the SOC of the traction battery if it sits for several days without being charged or driven.
2013 Leaf SV - Cayenne Red - QC Port - LED Headlights

arnis
Posts: 668
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 12V Battery Questions

Wed Jan 11, 2017 1:38 pm

2016 year Leaf doesn't have problems with 12V battery. Don't worry.
If it goes bad it goes bad. That happens with all cars.
I'm not sure about "switching OBD dongle off". Just remove it.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

sub3marathonman
Posts: 267
Joined: Wed Nov 03, 2010 11:57 am

Re: 12V Battery Questions

Wed Jan 11, 2017 6:31 pm

arnis wrote:Don't worry.
If it goes bad it goes bad. That happens with all cars.
I'm not sure about "switching OBD dongle off". Just remove it.


Or, you could get a CTEK charger and help the battery live longer without worrying about removing the OBD dongle every night. In my opinion it is a great charger, much better than the Battery Tender which I used to use back when I rode a Honda Rebel 250,

I have the CTEK 0.8, which is $51 at Amazon, or they have the MUS 4.3 for $69, which does everything the CTEK 0.8 does but can also be switched to charge at 4.3 amps instead of the 0.8 amps. In looking back, I think I would have spent the bit extra to get the MUS 4.3. A few other people on the forum here use the CTEK charger too.

One detail though, which the experts can hopefully correct if I'm wrong or confirm if I'm right, is that when charging the 12V battery hook up the + (Positive) lead of the charger to the + (Positive) of the 12V battery, but hook up the - (Negative) lead of the charger to the bolt where the Negative cable from the 12V battery is attached to the inverter and do not use the - (Negative) terminal of the 12V battery itself. I'm not really sure why attaching to the - (Negative) terminal of the 12V battery is so bad, especially if the LEAF is off, but as I understand it the experts do not want it hooked up that way, only to the bolt.

arnis
Posts: 668
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: 12V Battery Questions

Thu Jan 12, 2017 3:48 am

You pay for the charger and pay for parasitic electricity.
And whatever you try to do lead acid battery will still fail.
It will take longer. Most likely with trickle charging you will never break even.

Like I said, I would recommend somebody to try to disconnect current sensor at
negative terminal. I'm pretty sure that will result in 14.4V fixed mode on older Leafs.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

Reddy
Posts: 1317
Joined: Fri Feb 11, 2011 3:09 pm
Delivery Date: 18 Aug 2011
Leaf Number: 006828
Location: Pasco, WA

Re: 12V Battery Questions

Thu Jan 12, 2017 4:48 pm

PianoAl wrote:Our Leaf had been driven on Saturday, plugged in Saturday night. Not used and now, Monday evening I started up LeafSpy Pro, and saw that the 12V battery was at 11.96V
This seems a bit low and may lead to premature battery failure. I charge on L1 for several hours (instead of L2 for only a couple). During that time, my lead acid battery is being charged. Also, I periodically top it up with a CTEK trickle charger. I typically see about 12.6-12.8 V when checked. The CTEK charges it up to about 13.6 V. This is with the original 2011 battery, now almost 6 yr old. I typically get 7 years out of lead acid battery in this area. I'm hoping that this constant charging and topping up will keep the battery running for another couple years. So far so good, knock on wood.
Reddy
2011 SL; 10 bar, 48.82 AHr; 35,000 mi; rcv'd Aug 18, 2011
Long: http://www.mynissanleaf.com/viewtopic.p ... al#p226115"
Cold: http://www.mynissanleaf.com/viewtopic.p ... 60#p243033"

User avatar
RegGuheert
Posts: 5321
Joined: Mon Mar 19, 2012 4:12 am
Delivery Date: 16 Mar 2012
Leaf Number: 5926
Location: Northern VA

Re: 12V Battery Questions

Fri Jan 13, 2017 3:23 am

PianoAl wrote:Our Leaf had been driven on Saturday, plugged in Saturday night. Not used and now, Monday evening I started up LeafSpy Pro, and saw that the 12V battery was at 11.96V.

Q 1. That sound reasonable?
Reasonable? No. Typical for a LEAF? Yes. But I will say that you must have opened the doors to turn on LEAFSpy, so you likely awakened the car's electronics before your measurement. A better way to measure the 12V battery is to pop the hood when you park it and raise the hood and measure with a quality meter at a later time. Since the number you got is so low, I recommend you make such a measurement soon to ensure you do not get stranded somewhere.
PianoAl wrote:Q 2. How much SOC will I lose per day of non-operation?
Unplugged: about 3% of 12V battery is lost.
PianoAl wrote:Q 3. What's the highest SOC at which you would consider topping off?
For the 12V battery? They NEED to be topped off frequently. If you use a quality trickle charger, then anytime is fine.
PianoAl wrote:Q 4. Let's say the Leaf is left plugged in, and the SOC begins dropping. At what point will it top off on its own (if ever)?
Arnis has reported this happens daily on the 2016s and newer and does a decent job of charging the 12V battery. In earlier versions, it was every five days and the charging did not actually "top off" the 12V battery.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 3K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

powersurge
Posts: 546
Joined: Wed Oct 21, 2015 10:24 am
Delivery Date: 06 Dec 2014
Location: Long Island, NY

Re: 12V Battery Questions

Fri Jan 13, 2017 9:28 am

That CTEK charger may be good, but overpriced at $60.. I got my several battery tenders at Costco for $29 each..

Also, either hard wire the quick connect pigtails directly to the battery terminals or put clamps right onto the battery terminals. That stuff about not connecting to the battery is nonsense. the charger needs to measure the voltage right from the battery...

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