12 Volt Lead Acid Battery Replacement

[knightmb]

Thank you folks for helpful details on how the 12 volt is integrated into the Leaf's operation. I'm glad this forum is here. Otherwise owners who are interested in how their cars work wouldn't have much recourse. I will indeed climb the ladder with this local dealership if they don't put a new 12 volt in today. I think it would be useful to contact Nissan operations and register dissatisfaction with failure to correct a problem that triggers liability if a runaway Leaf crashes into something or someone. Complete negligence on their part. Were it not under warranty I, like many, would have replaced the bad battery with a good one right away.

Was looking at Leafy Spy app. It looks good. It appears to be designed to run on Android devices. I have an iPhone. There may be an Android app that would run Leaf Spy on an iPhone. Otherwise have to buy an Android, right? You would be able to monitor the voltage on the 12 volt as well as the lithium. If the the Leaf only needs 10.5 to operate--because I dd drive it to the dealership this morning to drop it off--then there should only be a 10.5 volt battery in the car--according to the reasoning of the service advisor. Anybody running Leaf Spy on iPhone?

Yeah, there is a LeafSpy for the iPhone as far as I know, you should be able to search it out in the apple store.

The Leaf only needs power to turn on the 400v pack, then the 400v pack provides 12 volt power (on top of driving, etc.). Think of the 12 volt as kind of a standby battery for the computer. If the voltage gets too low, even if it can turn on the bigger battery, the computer is not getting all the power it needs to run properly, so wonky things can happen. So even if the battery is sitting at 10.5 volts, as soon as you switch on the Leaf, it should jump up to +14 volts for the whole system (the power is now coming from the big battery). When you turn off the Leaf and disengage the big battery, the voltage drops back down to whatever the battery is at, now in standby. I don't know if the low voltage will trip any codes to later look at, some others here might have to chime in about that.

If there is a bad 12 volt or one with a bad cell as this one has--does the system set a DTC? I learned from this forum that a conventional ICE OBDII scanner won't work on a Leaf. Different parameters. No conventional combustion pollutants. Dealership said they checked the 12 volt--how? Must not have set a code due to low voltage. You would think Nissan engineers would make sure a low voltage 12 volt would set a code--since the car doesn't operate correctly or safely with a bad 12 volt.

The dealer might be just checking the car for codes and maybe the voltage isn't low enough to trip anything *yet*. But you've already physically tested the battery and one bad cell is bad for the whole battery. That bad cell is basically an inline heater due to the high resistance and it brings down the whole battery voltage and probably anything else trying to push power through it. So while the battery might not have a nuclear meltdown (they are engineered to be safe), it might be enough of a problem to interfere with the power levels on your 12 volt system to run the vehicle properly. The easiest test would be to simply replace the bad battery and see if all the problems go away. Otherwise, we might all be wrong and the problem is completely different?

 

[Nubo]

If there is a bad 12 volt or one with a bad cell as this one has--does the system set a DTC? I learned from this forum that a conventional ICE OBDII scanner won't work on a Leaf. Different parameters. No conventional combustion pollutants. Dealership said they checked the 12 volt--how? Must not have set a code due to low voltage. You would think Nissan engineers would make sure a low voltage 12 volt would set a code--since the car doesn't operate correctly or safely with a bad 12 volt.

When my battery went bad, it set about TWO DOZEN codes, including ABS brake module, etc..

The proper test of a battery is to apply a significant fixed load to it, and observe the voltage drop.

Your dealership is either staffed by people who don't know, or don't care. Best to steer clear. Don't try to teach a pig how to sing. It wastes your time, and it annoys the pig.

Find another dealer who does things right, or just get a replacement battery at the parts store. Well worth the savings in aggravation, imho. Size is Group 51R.

https://www.pepboys.com/product/details/844473/00847

 

[Flyct]

Anybody running Leaf Spy on iPhone?

If there is a bad 12 volt or one with a bad cell as this one has--does the system set a DTC? I learned from this forum that a conventional ICE OBDII scanner won't work on a Leaf. Different parameters..

For the iPhone there is no free LeafSpy APP but there is a $19.99 LeafSpy Pro App https://itunes.apple.com/us/app/leafspy-pro/id967376861?mt=8 It's well worth the money

You need a WIFI , not a Bluetooth Dongle for the iPhone and you need to follow the instructions to connect to it and configure the iPhone for a static IP for the Dongle. Then you need follow the APP settings page and click the button to Register the SSID as an OBDII Adapter .

I bought this WIFI Dongle that works http://www.amazon.com/gp/product/B00W8T51Y6 but it remains powered all the time. For now I just unplug it when its not in use.

I just ordered another dongle http://www.amazon.com/gp/product/B00PFFG1FS with ability to turn itself off after no communications for 30 minutes. The only downside to this one is that you need to push the flush button to turn it on once its asleep.. Still better that remaining powered up 24/7 and in my 2015 its easy to get to.

Here are a couple of screen shots I just took with my iPhone 6 and LeafSpy Pro. We were using the car all day and haven't charged it yet.

Notice 12 volt battery voltage at bottom left 14.16V with car ON and 12.80V immediately after turning the car OFF. It eventually settles around 12.50V

 

[Flyct]

LeafSpy Pro works great on IPhone 6 and on my iPad.

IOS installation instructions HERE:
http://www.mynissanleaf.com/viewtopic.php?f=44&t=19147

 

[Arlington]

Here are a couple of screen shots I just took with my iPhone 6 and LeafSpy Pro. We were using the car all day and haven't charged it yet.

Notice 12 volt battery voltage at bottom left 14.16V with car ON and 12.80V immediately after turning the car OFF. It eventually settles around 12.50V

I use LeafSpyPro too, and see the voltages but don't know what the answer is to "is that voltage that I'm seeing good or bad?" my question is, what kind of voltage will I see when the Lead Acid battery is failing? What kind of numbers mean trouble?

And is a new Lead Acid the cheaper-better-reliable solution (or even replacing it pre-emptively) vs some other technology (LiPo, NiMH,...)

 

[QueenBee]

Yeah, sounds like they only know the basics of the Leaf. The 12 volt powers the steering, fans, brakes, etc. The power inverter for the 12 volt system can only produce so much power (it's not infinite power of course) so if you have a bad lead acid battery in the mix, it is basically sapping the power that the rest of the systems need to function. The 12 volt battery is used to turn on the 400 v battery, that is true, but the basic car systems still use the 12 volt for safety reasons (can you imagine using 400 volts for your lights and other system?).

I'm pretty sure that the LEAF is smart enough to not continuously dump the 125+ amps that it can into the battery. It would be interesting to use LEAFSpy to watch the charge profile it uses on a bad battery like this.

Smart in that it will know if something is wrong and probably not continue to do this, but as others have have shown, you can hook a very power hungry inverter into the 12 volt system and pump out thousands of watts of AC without the Leaf doing anything different. The Leaf can't tell the difference between a battery and inverter, so it might be possible for a battery to turn into a heater?

Nope, the LEAF can tell the difference between an inverter connected properly and its own battery. That's why you never connect anything to the negative battery terminal. The LEAF monitors amperage into and out of the battery on the negative clamp. This is how it knows when to lower the voltage after its happy that battery has been recharged well enough.

 

[Flyct]

Here are a couple of screen shots I just took with my iPhone 6 and LeafSpy Pro. We were using the car all day and haven't charged it yet.

Notice 12 volt battery voltage at bottom left 14.16V with car ON and 12.80V immediately after turning the car OFF. It eventually settles around 12.50V

I use LeafSpyPro too, and see the voltages but don't know what the answer is to "is that voltage that I'm seeing good or bad?" my question is, what kind of voltage will I see when the Lead Acid battery is failing? What kind of numbers mean trouble?

And is a new Lead Acid the cheaper-better-reliable solution (or even replacing it pre-emptively) vs some other technology (LiPo, NiMH,...)

Generally speaking when it comes to lead acid batteries;

Here is a chart that shows state of charge on a typical lead acid battery when the car is "off".
http://www.mmbalmainauto.com.au/PDF/State_of_charge_12_volt_batteries.pdf

When the car is "on" it should be charging the 12 volt battery and it should read between 13.6-14.6, depending on temperature

 

[QueenBee]

Here are a couple of screen shots I just took with my iPhone 6 and LeafSpy Pro. We were using the car all day and haven't charged it yet.

Notice 12 volt battery voltage at bottom left 14.16V with car ON and 12.80V immediately after turning the car OFF. It eventually settles around 12.50V

I use LeafSpyPro too, and see the voltages but don't know what the answer is to "is that voltage that I'm seeing good or bad?" my question is, what kind of voltage will I see when the Lead Acid battery is failing? What kind of numbers mean trouble?

And is a new Lead Acid the cheaper-better-reliable solution (or even replacing it pre-emptively) vs some other technology (LiPo, NiMH,...)

Generally speaking when it comes to lead acid batteries;

Here is a chart that shows state of charge on a typical lead acid battery when the car is "off".
http://www.mmbalmainauto.com.au/PDF/State_of_charge_12_volt_batteries.pdf

When the car is "on" it should be charging the 12 volt battery and it should read between 13.6-14.6, depending on temperature

After its done charging it drops down to about 13 volts. Charging doesn't last long as it will do it very quickly and can push in a very high amperage if the battery is low.

 

[TimLee]

... When the car is "on" it should be charging the 12 volt battery and it should read between 13.6-14.6, depending on temperature

Completely wrong. That is for an ICE not a LEAF.

The LEAF inverter at Ready mode usually does 14.32V for a short time.
But if 12V has been badly discharged it can start at 100 amps or more and slowly decline till amps it is supplying drops to less than 9.9.

Then it will drop back voltage to around 13.8.
It will monitor current and at some threshold will drop back to 13V.

If 12V was badly discharged it will periodically jump back up to 13.8 and 14.32 depending on current flow.
I observed at least ten cycles over thirty minutes one time while LEAF was charging.

The problem with 12V with bad cell is that for some reason the LEAF fails to hold a stable 13V as 12V loads vary.

Voltages of the 12V do not always tell you the battery is bad.
Even the CTEK trickle charger would some times show it to be OK, but one time out of three it would show bad.

In some cases even the dealer capacity test machines have falsely shown a 12V to be OK when it was bad.

But in this case the 10.5 volts once loaded and the measured bad cell clearly show it is bad, even if the dealer capacity checking machine is showing it good.
Also possible the capacity test machine is defective.

 

[Flyct]

... When the car is "on" it should be charging the 12 volt battery and it should read between 13.6-14.6, depending on temperature

Completely wrong. That is for an ICE not a LEAF.

The LEAF inverter at Ready mode usually does 14.6V for a short time.
But if 12V has been badly discharged it can start at 120 amps and slowly decline till amps it is supplying drops to less than 9.8.

Thanks for the correction. I'm a newbee with the Leaf. That is why I started my reply with "generally speaking for lead acid batteries" etc.

The software allows 120 amps to be pumped into the small 12v Lead acid battery? That is weird..

Do you know how the software handles battery charge? Is it voltage controlled/current limited,, voltage limited/current controlled, or some other strange algorithm?

 

[QueenBee]

Do you know how the software handles battery charge? Is it voltage controlled/current limited,, voltage limited/current controlled, or some other strange algorithm?

I guess other. The only way it can control how much amperage goes into the battery is by adjusting the voltage but when it sets the voltage the battery can draw as much as it can at that voltage, Obviously there is a limit on the maxim that power output of the DC to DC converter but unless something is wrong that should never get hit.

 

[LeftieBiker]

I'm not sure what Tim was talking about, but the voltage of a Leaf's 12 volt battery should be at least 12.5 volts, and 13 or so volts when properly charged is normal. Readings in the 12 volt range or less indicate a nearly dead battery, just as with an ICE battery. The difference is that because it doesn't have to crank a starting motor, a nearly dead Leaf battery can still "start" the car.

 

[QueenBee]

I'm not sure what Tim was talking about, but the voltage of a Leaf's 12 volt battery should be at least 12.5 volts, and 13 or so volts when properly charged is normal. Readings in the 12 volt range or less indicate a nearly dead battery, just as with an ICE battery. The difference is that because it doesn't have to crank a starting motor, a nearly dead Leaf battery can still "start" the car.

You are referring to the voltage after the battery has throughly rested without a load on it. Any measurements taken while the battery is connected to the LEAF are not resting voltages and are wth a load on them.

 

[Redwomack]

12 volt replacement update. Dealership put in a new 12 volt finally on second visit. Found multiple codes had indeed been set: C1109, C118c, P0A8D, P3178, P0A8F, and C1A90--all described as low 12v. Also "Failed battery code: Bat TD4 LTH EWO 73J." Also, Tested 12v battery with GR8 testing system--charge and recheck. Group 51R. Looks exactly like the bad one but now shows 12.55 v after returning home.

It's interesting that all these codes can be set and the car continues to run--sort of----and the unaware driver doesn't get the old ICE warning check engine light--not an emissions issue obviously. And what about this elaborate carwings program. Isn't the car supposed to communicate with the Mother Factory somewhere in Tennessee or Japan and report that the Leaf is out of sorts--come to the rescue? What a crazy notion.

You guys were dead on with your analysis. Too bad dealerships don't trust what the drivers tell them and act accordingly. Use a little common sense and test the battery in the first place. This is a very valuable forum.

 

[TimLee]

I'm not sure what Tim was talking about ...

The discussion was about Redwomack's battery problem.
Battery voltage was 10.5 which clearly was abnormal.

 

[TimLee]

12 volt replacement update. Dealership put in a new 12 volt finally on second visit. ...

It's interesting that all these codes can be set and the car continues to run--sort of----and the unaware driver doesn't get the old ICE warning check engine light--not an emissions issue obviously. And what about this elaborate carwings program. Isn't the car supposed to communicate with the Mother Factory somewhere in Tennessee or Japan and report that the Leaf is out of sorts--come to the rescue? What a crazy notion.
...

Glad the incompetent service department did the right thing on the second visit.
Be sure you give them a zero rating on their evaluation.
Nissan needs to provide them with a lot of remedial education.

I agree that the LEAF not providing the driver any notice of a serious problem that can make the vehicle unsafe to drive is a serious design flaw.

Carwings does not provide any vehicle information to Nissan.
Was not designed to do that.
Only information Nissan gets is from the annual high voltage battery test.
Not really a test.
Just data collection.
And a report card to the driver on how their behaviour is impacting battery life.

 

[dhanson865]

I'm not sure what Tim was talking about, but the voltage of a Leaf's 12 volt battery should be

1. Leafspy will only show you a battery voltage when the OBDII port is active which means either

a. the car is charging via EVSE or CHaDemo
b. the car is powered up to accessory, ON, or Ready states
c. the car is awake for purposes related to scheduled events or timer overide or some other generalized event that wakes up part of the cars systems enough to power the ODBII port

2. There are multiple ways to measure voltage on the 12v battery and multiple loads it could be exposed to and you can't compare voltages from different methods/states/loads as apples to apples.

See http://priuschat.com/threads/new-optima-battery-doa-almost-and-getting-worse.102453/page-4#post-1493405 for an example of how voltage differs between two measurement methods and varying loads.

Tim was talking about the voltages the inverter would supply to the 12v bus that would indirectly charge the 12v battery. These numbers will be higher than anything that tells you anything about the health of the battery directly. Indirectly it tells you how much power the Leaf is trying to send that way but it's mixed in with any other loads on the 12v bus.

Leafspy is a great tool but if you want to accurately test your 12v battery you'll have to pop the hood and use a hand held voltage meter (DMM set to the proper method and range or an auto ranging meter). And you'll have to do so repeatedly on multiple vehicles or with the same vehicle and multiple batteries just to figure out what the normal baseline figures should be with an ideal battery vs your battery that might be questionable.

 

[LeftieBiker]

Leafspy is a great tool but if you want to accurately test your 12v battery you'll have to pop the hood and use a hand held voltage meter (DMM set to the proper method and range or an auto ranging meter). And you'll have to do so repeatedly on multiple vehicles or with the same vehicle and multiple batteries just to figure out what the normal baseline figures should be with an ideal battery vs your battery that might be questionable.

OR, you can just measure the rest (let it sit for at least 15 minutes with all power off before testing) voltage of your Leaf's battery, and if it isn't at least 12.5 volts, assume that the battery is undercharged. (No voltage reading will tell what the capacity is, only the relative state of charge.) No need to reinvent the wheel when we have so many people regularly measuring our Leafs' accessory battery voltages...

 

[dhanson865]

Leafspy is a great tool but if you want to accurately test your 12v battery you'll have to pop the hood and use a hand held voltage meter (DMM set to the proper method and range or an auto ranging meter). And you'll have to do so repeatedly on multiple vehicles or with the same vehicle and multiple batteries just to figure out what the normal baseline figures should be with an ideal battery vs your battery that might be questionable.

OR, you can just measure the rest (let it sit for at least 15 minutes with all power off before testing) voltage of your Leaf's battery, and if it isn't at least 12.5 volts, assume that the battery is undercharged. (No voltage reading will tell what the capacity is, only the relative state of charge.) No need to reinvent the wheel when we have so many people regularly measuring our Leafs' accessory battery voltages...

or measure the rest HOW?

Your response is pretty vague.

Are you suggesting to measure with a DMM or leafspy or some other method?

Are you testing rest voltage with the car off or in accessory mode or on?

 

[TimLee]

I'm not sure what Tim was talking about, but the voltage of a Leaf's 12 volt battery should be

...
Tim was talking about the voltages the inverter would supply to the 12v bus that would indirectly charge the 12v battery. These numbers will be higher than anything that tells you anything about the health of the battery directly. Indirectly it tells you how much power the Leaf is trying to send that way but it's mixed in with any other loads on the 12v bus.

Leafspy is a great tool but if you want to accurately test your 12v battery you'll have to pop the hood and use a hand held voltage meter (DMM set to the proper method and range or an auto ranging meter). And you'll have to do so repeatedly on multiple vehicles or with the same vehicle and multiple batteries just to figure out what the normal baseline figures should be with an ideal battery vs your battery that might be questionable.

The discusion was about Redwomack's statement on page 15:

Have recently bought (10/4/15) a "2015" Leaf that actually was built in August 2014. Have been reading posts to this forum regarding 12 volt lead acid battery issues. Recently took Leaf into dealer for software upgrade for brakes. Have had the car try to run away in forward and reverse. Has done it once since dealer brake software upgrade--Campaign P5327 (Intelligent Brake Control Unit). Have checked "12 volt" battery a number of times and found the voltage at 10.50 to 10.65 range. Wondering if this is normal. It wouldn't be normal on a conventional ICE battery. Should be in the 12.26 range at rest, right? Couple of days ago it wouldn't shift into forward or reverse. Read the owners manual for a while. Turned it on and off several times. Sat for a 5 minutes or so reading. Tried it again and it went into forward and I took off.

Could the "low" voltage readings I've gotten be affecting the car's performance? ...

Redwomack apparently took resting 12V battery voltage with a DMM.
10.5 V clearly was low and inadequately charged or defective with bad cell and dealer should have been knowledgeable to fix that on first visit.

Later discussion was about DC to DC voltages when the LEAF is charging or in Ready.
Those do not give you much knowledge about the 12V condition.

Even resting 12V DMM voltage is a bit limited piece of data.

Real assessment of 12V condtion requires battery tester.