NwCali6
Posts: 8
Joined: Wed May 19, 2021 5:41 pm
Delivery Date: 20 May 2021

Adding 12volt PV charging system

Sat Jun 05, 2021 2:09 pm

Not sure if I'll get the right answer, but I'm going to ask.

I assume the Lithium battery charges the 12volt battery for things like lights/fans and maybe even the inside computers. Does anyone know for sure what is (and isn't) ran from the 12 volt batter?

Once we have that known I would like to ask this, if you put a solar panel on your car and ran it to a charger that supplied the 12volt battery this should (hopefully) lessen the load of the lithium to 12volt converter system, which would, hopefully, increase the range of the drive (lithium) batteries.

Of course Nissan might have made things go all goofy if one tried this...

Mine is a 2011, new to me...so warranty isn't a "issue" but I also don't care to brick my car...

Any thoughts?

LeftieBiker
Moderator
Posts: 17105
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Adding 12volt PV charging system

Sat Jun 05, 2021 3:48 pm

All of the accessories except the heat pump (if present), and heater run on 12 volts, including the HVAC blower. You are not incorrect, but the range consumed by these accessories would be measured in fractions of a mile. A solar panel, properly connected to prevent it from draining the 12 volt battery at night, would be a good idea, but not really as a way to extend range.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

knightmb
Posts: 973
Joined: Mon Jan 12, 2015 7:41 pm
Delivery Date: 26 Feb 2021
Leaf Number: 306291
Location: Franklin, TN

Re: Adding 12volt PV charging system

Sat Jun 05, 2021 6:31 pm

NwCali6 wrote:
Sat Jun 05, 2021 2:09 pm
Once we have that known I would like to ask this, if you put a solar panel on your car and ran it to a charger that supplied the 12volt battery this should (hopefully) lessen the load of the lithium to 12volt converter system, which would, hopefully, increase the range of the drive (lithium) batteries.
It depends on the battery used. Some of us here (including myself) have switched to a Lithium 12V auto battery. The factory installed Lead Acid battery just don't survive well in a Leaf because the inherit technology of Lead needs the battery to be fully charged all the time to avoid decay. While the DC to DC converter keeps the battery charged, it's not the same kind of exercise for the battery that is installed in an ICE. When you start an ICE vehicle, you are pulling a hundred amps for a few seconds to start the car, then the alternative blast a hundred amps back into the battery and keeps it at the +14V range the entire drive. The Leaf just keeps enough voltage to run the 12V stuff (usually hangs around +13 volts), while that is enough to charge the battery, it doesn't really keep it "topped off". SLA battery work better in this kind of use so many here recycle the old Lead Acid and go with SLA, others go with the Lithium.

Having written all that... a dead or dying Lead Acid battery has just enough power to start a Leaf but not much else. A dying Lead Acid battery then turns into more of a heater, wasting energy to keep it topped off. Probably not enough to make a difference in range because of the scale of power to "push" the Leaf down the road is so many magnitudes higher than what the battery is wasting. A dying Lead Acid battery also causes CPU issues in the Leaf with phantom DTC codes or weird car behavior or issues. That's why about 99% of the responses here with troubleshooting is "check the 12V battery". :lol:

In Theory, say you installed a 1.2 kWh 12V Lithium battery (I think it would fit in holder) and did a long drive with the intent of running the Leaf until the battery was completely drained, you might save 3 or 4 miles over the *entire* trip provided you already fully charged the 12V Lithium externally before starting the trip. A battery that size would cost probably +$600, so very expensive to save only a few miles.
2020 Leaf SL Plus - (Manufacture Date March 2020)
2013 Leaf SV (8 faithful years of service before trade in at 75,679 miles)
Timekoin - The World's Most Energy Efficient Encrypted Digital Currency

NwCali6
Posts: 8
Joined: Wed May 19, 2021 5:41 pm
Delivery Date: 20 May 2021

Re: Adding 12volt PV charging system

Sat Jun 05, 2021 7:16 pm

Well, thanks for the replies. I think, in the long run, it would make sense to have a solar panel keeping the 12volt going. Meaning over the 80,000 miles my car has ran it would have paid for itself, in a small part by not draining the drive battery (which you have to pay to charge) but by also keeping the drive batteries from draining as much (to keep the 12v battery going), hence keeping them "healthier"...

Yes I can overthink things at times. :)

But it would have been nice if Nissan would have covered the skin with a PV skin that would even charge the drive batteries while driving, and given enough time could top them off when not driving. You could go for a movie and come back out with 4 extra miles in the tank...or leave work with 20 extra miles.....

Yeh I know, cost versus benefit

LeftieBiker
Moderator
Posts: 17105
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Adding 12volt PV charging system

Sat Jun 05, 2021 7:18 pm

The other, more popular option, is to install a higher capacity AGM battery. While still SLA chemistry, AGM batteries seem to work better with the Leaf's mediocre 12 volt charging system. And they cost much less than lithium batteries.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

MyNLsfbay
Posts: 1
Joined: Fri Apr 12, 2019 11:17 pm
Delivery Date: 19 Mar 2019
Leaf Number: 026493

Re: Adding 12volt PV charging system

Sun Jun 06, 2021 11:55 am

I'm the third owner of a 2012 Nissan LEAF. I opened the hood and took a picture of the 12volt battery, and it looks like it is a replacement and not the original. I wanted to take a look at the battery because lately things have been strange on switching on the LEAF. One time, I braked and started the car. The dashboard told me I needed to step on the brake to turn on the car. So I turned it off again to repeat the process. This process repeated several times until I got to a different screen that showed all indicators active and for me to visit a dealer near me. In other words, the car failed to start so that I could use it.

Thankfully, I was parked in such a way that I could charge my car. So I did. I let it charge to 100%. The next time I turned on the car, it worked and gave me no signs of inability to power up and drive. So I thought nothing of it.

Then something scary happened yesterday. I turned on the car, had released the parking brake, had my foot on the brake pedal and it was moving back by itself. I quickly used the parking brake again, then switched the car to drive forward to see if it would move forward. (It did.) Then I parked and turned the car off. Then I switched the car on again and moved forward as well as back to see if the car would respond correctly. It did. So I went to my next errand and parked there.

However, the next time I started the car, the brake pedal was still shown to be on even after I had released it and was putting the car into drive mode. That scared me. So I parked the car, put the parking brake on, switched the car off, and then turned it on again. I think I might have repeated this twice. The third time, it operated as if nothing weird had happened.

I am assuming that all these weird problems are due to the 12volt battery acting up. I already reached out to a Nissan dealer to see if they replace 12volt batteries. I am also wondering if I need a diagnostic to see if it's only the 12volt battery acting up? What do you suggest? Given what I've seen, it looks like instead of lead acid and lithium, I should consider the AGM instead? Thanks in advance!

LeftieBiker
Moderator
Posts: 17105
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Adding 12volt PV charging system

Sun Jun 06, 2021 1:41 pm

I am assuming that all these weird problems are due to the 12volt battery acting up. I already reached out to a Nissan dealer to see if they replace 12volt batteries. I am also wondering if I need a diagnostic to see if it's only the 12volt battery acting up? What do you suggest? Given what I've seen, it looks like instead of lead acid and lithium, I should consider the AGM instead? Thanks in advance!
You almost certainly have a bad 12 volt battery. The dealership will charge an arm and a leg to replace it, and will install the poor quality (since 2013) OEM battery. The AGM battery is just a better type of lead-acid, with fiberglass matting inside to discourage the formation of lead sulfate crystals. Make sure that whoever installs a new battery, that it is fully charged either before installation, or immediately afterwards. This isn't typically necessary with regular cars, but it's a very good idea with a Leaf.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

User avatar
bobkart
Posts: 243
Joined: Sat Dec 22, 2018 12:17 am
Delivery Date: 14 Dec 2018
Leaf Number: 307853
Location: Pacific Northwest
Contact: Website YouTube

Re: Adding 12volt PV charging system

Fri Jul 16, 2021 11:12 pm

The vehicle I had before the Leaf was a Mazda B2300 pickup, and after buying the Leaf it sat parked most of the time, so the 12V battery would end up nearly dead in winter. I got a 25W solar panel and put it on the dashboard under the windshield, then used a charge controller to connect it to the cigarette lighter outlet. Fortunately the outlet was live even with the ignition key off. This solved the problem of the battery running down after weeks of not being started.

Here is that charge controller:

https://www.altestore.com/store/charge- ... es-p10622/

You just need to make sure whatever solar panel you connect it to has the right parameters (voltage, current).

For the Leaf, the 12V outlet under the dashboard isn't live when the car is off, so you'd need to make the connection to the 12V battery some other way.
Pearl White 2016 Leaf S, 24kWh battery
Silver Enkei Racing RPF1 16x7 Wheels
Ohmmu T12403 LiFePO4 12V Battery
Nissan All-Season Floor Protectors

ClipperCreek LCS-25P
2x REC 325Wp Solar Panels
10kWh LiFePO4 Battery Bank
BAFX OBD2 Reader, LeafSpy Pro

User avatar
Nubo
Posts: 6006
Joined: Fri May 28, 2010 11:01 am
Delivery Date: 31 Oct 2014
Location: Vallejo, CA

Re: Adding 12volt PV charging system

Sat Jul 17, 2021 7:33 am

NwCali6 wrote:
Sat Jun 05, 2021 7:16 pm
Well, thanks for the replies. I think, in the long run, it would make sense to have a solar panel keeping the 12volt going. Meaning over the 80,000 miles my car has ran it would have paid for itself, in a small part by not draining the drive battery (which you have to pay to charge) but by also keeping the drive batteries from draining as much (to keep the 12v battery going), hence keeping them "healthier"...

Yes I can overthink things at times. :)
For the first couple of years, LEAF did include a solar panel on the rear spoiler. Whether it did anything useful is open for debate. It's important to keep scale in mind. While driving along at 60mph the motor maybe getting about 4 miles per 1000 Watt-hours. Typical accessory usage is more along the lines of 300 watts, which over the course of those 4 miles equates to 20 Watt-hours. Then factor in the size of solar panel area it would take to generate 300 watts throughout the day. To install something that large without negatively affecting aerodynamics would be quite a project. The return on investment trying to save a tiny fraction of your electric cost seems incredibly poor. You can improve your cost much more easily and effectively by adopting efficient driving habits.
I noticed you're still working with polymers.

Return to “Range / Efficiency / Carwings”