My biggest concern is burning down the house with the use of a non-enclosed organic based fire hazard. Lead acid has water as a solvent while the replacement is filled with something as bad as gasoline as a solvent. Just stick with OEM and add water every 6 months when you check the voltage. Only question I have is should I go with AGM?
12v Lithium Iron Phosphate New Battery Available
- Thread starter vgabbott
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Help Support My Nissan Leaf Forum:
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Learjet
Well-known member
yes "Game Changer" is a very over used phrase.
One thing I noticed is that every time you charge the main battery and every time you energize the car a 14 volt charge is placed on the house battery whether it needs it or not?
Jerther
Well-known member
Yep, pretty much useless for us Canadians.
Anyways, all theoretical stuff aside, and assuming it's a safe drop-in replacement and all goes well, at this point I understand I'll have to slice off a good chunk of my wallet to get a decent lithium 12v battery and the only significant and practical benefit I'll see from it is extended durability, which means it might be the only and last battery I buy for this car. Although I've never changed the lead acid on my zuki SX4 for the decade I've owned it... anyways, not convinced. I'm trying, I really am. I like new stuff. I'll keep reading here
I'm not either. Actually the Leaf architecture is about the ideal use for a lead acid battery. low current with frequent recharges that can be independent of "engine speed". or even "car on".Yep, pretty much useless for us Canadians.
.. anyways, not convinced. I'm trying, I really am. I like new stuff. I'll keep reading here
It comes down to the charge regimen being correctly done. Because there is a whole lot of variation in life-span reported, and some evidence that the voltage reported to the VCM (reported by Leafspy) varies from that measured at the battery terminals. It is not clear if the regimen is faulty or the sensors that control it are giving erroneous info.
What is clear is that it works well enough on some cars and less well on others.
I'd be interested in a breakdown on the lines of higher level trim and base (ones with and without the solar on the rear spoiler) in battery life.
From my memory and stand to be corrected if my info is false:
Charge take place:
1) key on ready mode
2) charger connected
3) non use for 4 min every 24 hr of sitting off.
4) There are other misc times the charger works for a limited time.
The charge doesn't consist of a set voltage, but is initially around 14.4 volts, at which time the VCM looks at the battery voltage, temp and current needed to hold that voltage, using that to assess the SOC in the battery. Once current drops to a set level, the VCM tapers the charge down to float voltage.
Obviously, and mis reading of the actual voltage at the battery or current flowing to it would throw off the VCM's reading of SOC.
There are two ways that inputs to the VCM could be manipulated to try and adjust the charge. One is the temp sender on the battery, but a vastly differing reading on the battery vs. other temp senders in the car would likely just throw a code. The other is the current shunt at the battery, if one was able make small changes to its reading, it should be possible to delay when the VCM tapers the voltage to float voltage.
Ideally one would like to be able to control all the perimeters that control the 12 volt charging. I would raise the "bulk charge" voltage to closer to 14.8~9 and play with the current when it switches to absorbsion/float charge. This would require being able to adjust the actual program.
I still think that useful changes can be made at the current shunt, that would improve the SOC while still retaining the basic protocol.
So far I have only received "spam" replies to my query for a used current shunt to play around with.
I and many have known this for over 10 years!
Sorry for your memory lapse, but the key initial issue many have complained about while driving, was that the OEM battery was NOT being adequately charged, i.e. greater than 13.5 - 13.8. So those with concern sought other battery technologies. Many have used the wipers-on
mode to increase the charging voltage. Based on my experience, it's a total waste of time and money seeking a battery "upgrade",
especially with battery technologies requiring higher charging voltages than the OEM Leaf battery.
Consider monitoring the 12V charging process at other modes besides while the traction battery is being charged!
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" Actually the Leaf architecture is about the ideal use for a lead acid battery. low current with frequent recharges that can be independent of "engine speed". or even "car on".
It comes down to the charge regimen being correctly done."
In theory, yes. In practice the leaf keeps its 12 volt battery chronically undercharged, to about 12.2 volts or less, in my experience...
It comes down to the charge regimen being correctly done."
In theory, yes. In practice the leaf keeps its 12 volt battery chronically undercharged, to about 12.2 volts or less, in my experience...
The odd thing is that doesn't seam to always be the case. Not EVERYONE reports that problem, SOME do, and I'm not discounting those that do, but it seam some variance in results.
I agree that Nissan could have done better. They were weighing charging vs. the range reduction. I will say I don't think they got it right, but don't think either the choice of a lead acid battery nor the type charging is at fault, rather it the compromises they chose.
Learjet
Well-known member
If you drive in the rain a lot, the battery will get charged better, since the converter switches to ~14.4 volts with the wipers on. If you use you car more, the battery gets charged more. I think that is what makes the 12v battery life different for everyone.
Jerther
Well-known member
What about that black wire on the negative terminal on the battery that some people disconnect to """improve"""" battery charging?
All that does is disconnect the current sensor. The VCM then goes into "fail-safe" mode as far as charging. voltage is around 14 volts in fail safe, no idea if it restricts the maximum current. No idea on how it effects other aspects of the charging protocol.
Except you pretty much have to charge the traction battery every week (unless you just don't drive)...and Lithium starter batteries hold their charge much better than lead-acid.
Like I said: EVs are perfect for Lithium starter batteries (obviously don't have to "charge" an ICE to use it).
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In my leaf (2019 model) the black negative wire goes directly to ground, wihout sensors. The positive had a little black box , so i think that the battery current sensor is on " + " pole....
My 12V batery is the original one.
My 12V batery is the original one.
Old batteries have lower capacity and higher resistance. So, they discharge quicker. True for ALL rechargeables. Pb has a very abrupt 'fall off' lower voltage. So a battery that seems to be good one day, oddly won't work the next. If you track voltage daily, you'll see it.
ANY GOOD battery should handle 2 weeks without a problem.
I've looked into solar chargers. Lots of people have poor results from them. I would not expect one to be a life preserver for an old battery, probably any battery.
(Note - I did exactly like you were doing on my 8 year old Prius Pb-charged weekly. I did that for 2 years as the Prius battery is stored in the 'trunk', needs a vent tube, so replacement options are scarce and expensive. It was fine at a week, would not go 2 weeks.)
Don't know about the Tesla, but do not leave a Leaf on main battery charge for ANY extended period of time. Not good for traction battery OR 12v.
There are extensive warnings about that in the forum.
You CAN leave the 12v on a trickle charger if you have a situation that allows that (garage). Doesn't matter if AGM or flooded Pb.
You do not need a BT enabled battery. Not sure it's worth the extra $100, but I don't need or know about the self warming capability. I did wire in a small LED voltage checker so I can open the hood and know immediately what the charge state is.
These things keep coming down in price. IMO, go for it.
Learjet
Well-known member
Don't forget, after shutting off car the 12v battery gets charged for 5 mins every 24 hours of sitting. Probably not long enough for a Lead Acid battery to make a real difference, but a Li will such up some juice in 5 mins.
Ummm...no. At least not for the Gen1 (which he has).
I can't believe how much mis-information is propagated about the Leaf and 12v batteries (all types)--in many, many threads.
Learjet
Well-known member
Depends on your definition of 1st gen, '11-'12? 24kwh? older body style?
According to the SERVICE manual for 2015, it does charge if left over 24hr. Now whether you consider a 2015 1 or 2nd gen may play into whether the 2015 manual if applicable.
"which he has" who has? the O/P never stated the year.
Generally speaking, a major body style change is what is referred to in 1st vs 2nd generations, but it can mean other major changes. but there is no set in stone definition.
The compromise, ad hoc definitions for Leaf gen designations are:
2011-2012 - Gen 1
2013 - 2017 Gen "1.5"
2018 - ? Gen 2.
2011-2012 - Gen 1
2013 - 2017 Gen "1.5"
2018 - ? Gen 2.
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