Solutions to 12 Volt Batteries and Chargers Posted Here

[lorenfb]

How long did you leave the wipers on? Also, how often does LeafDD sample the voltage of the 12V bus? Only your low beams are LEDs. Your high beams are halogens.

1. The wipers were on the length of the outbound trip, i.e. about 45 minutes. The wipers were left
on a few minutes each time during the return trip and the voltage didn't change. Today I'll leave
them on longer and see if there's more of a delay factor. Remember, there're other motor loads,
e.g. the inside fan blower motor that even draws more startup/run current than the wiper motor.

2. The LeafDD sampling rate is much greater the my LeafSpy since the LeafDD samples less data.
The 12 volt battery voltage is sampled at less than every minute.

3. The LED highlights were indicated because they draw less current than halogens and that some
Leafs lack LEDs. So they provide less of a load on the 12 volt battery, thus being less of factor in determining
the Leaf's charging voltage than would halogens.

Update:

It does take a little over a minute before the battery voltage reaches the 14.3 to 14.5 volts after
the wipers are turned on. The voltage remains at that voltage for another minute or two after
the wipers are turned off, at which point the voltage is at 13.0. It now appears that no other
loads, e.g. heater/fan blower at any setting, will cause the charging voltage to increase to the
higher level other than the wipers. Further testing, though, needs to be done to determine
if other conditions exist where the battery is charged to a higher voltage than 13.0.

Anyone want to discuss the trade-off between wiping a dry windshield to save the 12V battery versus the cost of replacing a scratched windshield and worn wiper blades?

Again, that's YOUR assumption that the Leaf battery needs supplemental charging!

 

[dhanson865]

No need to unplug the BatteryMinder. It *always* desulfates.

12.46

I'm going to stop this simple test today after 21 full days of monitoring since the weather is getting hot now and I want to charge and desulfate the battery before the sulfate has a chance to fully harden.

But I have never charged the LEAF battery when fully dead. As a result, it has never taken more than about 10 hours to fully charge and drop back to float. Normally, if I do it periodically, it is done in a few hours.

Today's charge starting from 12.46V was the first one I have done in over three weeks. The BatteryMinder 1500 took 6.6 hours to complete the bulk and absorption phases before dropping down to float. It spent less than two hours in bulk phase before getting the voltage up to the absorb voltage of 14.5V, so the time to complete the charge using any faster charger would only be reduced by some amount smaller than those two hours.

Either the battery minder actually does bulk before duslphating or it always desulfates, which is it?

In the case of CTEK it desulphates before bulk charging, then bulk charges, then tops up but at any point can automattically start over if needed

MULTI US 3300 operates in a four step fully automatic cycle. It starts the charging with an almost constant current (0.8A or 3.3A) until maximum voltage (14.4V or 14.7V) is reached. At this point the charger switches to constant voltage, and the current supply to the battery is gradually reduced. If the current drops to 0.4A, the charger switches to pulse maintenance. If the battery is charged and the terminal voltage of the battery falls to 12.9V, the charger automatically starts again at the first step of the charge characteristic. The MULTI US 3300 measures both voltage and current in order to determine out whether the charging process is finished or whether a new charging cycle must be started.

Desulphation: Desulphation with pulsing for sulphated batteries.

Bulk: Charging where about 80% of the energy is returned. The charger delivers an almost constant current until the battery voltage reaches the set level.

Absorption: Charging up to almost 100%. The charge current tapers and the voltage is kept constant at the set level.

Pulse: Maintenance charge. The charging process ranges between 95% and 100%. The battery receives a pulse if the voltage falls.

So I'm not sure if you have the phases in the right order for your batteryminder or if you think it actually desulphates non stop during any phase of the charge session.

 

[QueenBee]

Reg, does the new found info about the higher voltage with windshield wipers change your mind about the usefulness of the always installed desulphator?

 

[dhanson865]

leafspy says my 12v battery was hanging around 12.1x V. I put some distilled water in all 6 cells and put it on the CTEK for a few hours and got it up to 12.8x V. Took it off the charger and by the time I got to work (15 miles later) the last reading was 12.64V.

12.32v after driving a couple of miles for lunch.

btw the battery in my Prius is DS46B24R which is 38 ah. I'm not sure of the ah rating for the Nissan OEM battery in my leaf. Anybody know the specs?

 

[RegGuheert]

Either the battery minder actually does bulk before duslphating or it always desulfates, which is it?

The BatteryMinder desulfates during all three phases of the charging: bulk charging, absorbtion and during float (which it will do until you disconnect it). I have desulfated the battery for weeks at a time.

The ONLY time the BatteryMinder does not desulfate the battery is during a 10-minute resting period between the absorption charge and float charging. The unit allows the battery to rest for 10 minutes with no load to determine if it is beyond recovery. If the voltage drops below 12.5V during that brief period, it will NOT continue with the float charging portion and will instead flag the battery as failed.

Reg, does the new found info about the higher voltage with windshield wipers change your mind about the usefulness of the always installed desulphator?

No. It will help someone like you with an often-rainy climate to get a longer life out of your 12V battery, but you have periods of no rain even where you live. During that period, the lead sulfate in your battery will harden and permanently remove capacity from your battery.

But didn't you say you use a BatteryMinder occasionally?

 

[lorenfb]

During that period, the lead sulfate in your battery will harden and permanently remove capacity from your battery.

You continue to make this speculation with no long term proof! Why do you potentially mis-lead Leaf
owners without ANY data about the extent of 12 V battery sulfation verses charging voltage?
Where are the actual capacity loss data, only voltage data have been presented without ANY current
measurements, e.g. load tests, Ahr measurements? Simple voltage measurements are NOT a valid
indication of capacity loss.

Furthermore, have you attempted to determine other modes/conditions under which the Leaf charges
at higher voltages than 13.0 as was recently determined? How was this mode (wipers on) not discovered
by you and others, given the length of this thread & time, and ALL the battery voltage measurements
taken to the tens of millivolts?

 

[LeftieBiker]

Again, that's YOUR assumption that the Leaf battery needs supplemental charging!

Quite a few of us have come to that conclusion, usually after having the accessory battery die at least once, for no obvious reason. I was very lucky in that mine got low enough to disable the power locks, but not too low to just barely boot the system.

 

[QueenBee]

Reg, does the new found info about the higher voltage with windshield wipers change your mind about the usefulness of the always installed desulphator?

No. It will help someone like you with an often-rainy climate to get a longer life out of your 12V battery, but you have periods of no rain even where you live. During that period, the lead sulfate in your battery will harden and permanently remove capacity from your battery.

But didn't you say you use a BatteryMinder occasionally?

I have been more so as the result of this thread but I don't remember to go out and hook it up after the car has finished charging the traction battery very often.

 

[QueenBee]

Again, that's YOUR assumption that the Leaf battery needs supplemental charging!

Quite a few of us have come to that conclusion, usually after having the accessory battery die at least once, for no obvious reason. I was very lucky in that mine got low enough to disable the power locks, but not too low to just barely boot the system.

Have you had the software update that addresses one cause for this in 2013s?

 

[RegGuheert]

I have been more so as the result of this thread but I don't remember to go out and hook it up after the car has finished charging the traction battery very often.

I don't do it very regularly, either. In the wintertime the issue of sulfation hardening is not a significant concern, so I probably only charge the battery once every three months (or longer). But this time of year I try to do it at least once a month.

 

[QueenBee]

Where are the actual capacity loss data, only voltage data have been presented without ANY current
measurements, e.g. load tests, Ahr measurements? Simple voltage measurements are NOT a valid
indication of capacity loss.

I'm very curious what some recommended tool(s) would be to get accurate capacity measurements.

 

[dhanson865]

Simple voltage measurements are NOT a valid indication of capacity loss.

We aren't concerned with capacity loss. We are concerned about reliability aka performance.

If the voltage goes too low some or all systems will not work. I don't care about the capacity of the battery to deliver 10v, I care about the ability of the battery to reliably deliver the highest voltage possible over the longest number of months of ownership.

I'm not looking to run my radio for hours on end in accessory mode. I'm looking for the MFD, dash, and main battery connector motor to still work so I can get in my car and drive away as I normally do.

capacity is the wrong metric for "will it work" at a single instance.

 

[lorenfb]

Where are the actual capacity loss data, only voltage data have been presented without ANY current
measurements, e.g. load tests, Ahr measurements? Simple voltage measurements are NOT a valid
indication of capacity loss.

I'm very curious what some recommended tool(s) would be to get accurate capacity measurements.

Up-thread there was posted a typical analog load tester from SnapOn Tools. There are digital ones also
available like many Nissan dealers use on all ICE vehicles when they enter the service bay for ANY service.
Doing a load test is common at most all ICE dealers now to effectively evaluate the 12 volt lead acid battery.
Measuring just the voltage at the dealers' service departments would provide little insight into the actual
condition of the vehicles' 12 volt battery.

Next time one visits an automotive dealer watch what most all service departments do even before the
vehicle is routed to each mechanic's service location, i.e. the 12 volt battery evaluation. Not doing
an effective 12 battery evaluation as a first step in any vehicle maintenance places the dealer at risk
of not notifying the vehicle's owner of a key basic vehicle problematic issue.

 

[RegGuheert]

We aren't concerned with capacity loss. We are concerned about reliability aka performance.

If the voltage goes too low some or all systems will not work. I don't care about the capacity of the battery to deliver 10v, I care about the ability of the battery to reliably deliver the highest voltage possible over the longest number of months of ownership.

I'm not looking to run my radio for hours on end in accessory mode. I'm looking for the MFD, dash, and main battery connector motor to still work so I can get in my car and drive away as I normally do.

capacity is the wrong metric for "will it work" at a single instance.

+1

We now KNOW that the LEAF battery charger only ever returns the battery to 100% charge on very rare occasions, if ever (and that it even depends on the weather!). Failure to return the SOC to full frequently is the long-known cause of lead-acid battery sulfation and is very likely the main reason that many LEAF 12V batteries have died well before their times.

Personally, I care about whether my LEAF will leave me stranded or not. As such, the slope of voltage when sitting in the car doing nothing is really the main parameter that tells me about battery health. I have baseline information from 2012 and now new data in 2014 to tell me how quickly the battery voltage drops when healthy. Now if I take a couple of daily measurements when the car is sitting and I see a much higher slope, I will know that either the battery has lost significant capacity or there is some new load involved (such as the ELM-327 is plugged in).

If I ever find that the battery voltage is below 12V after sitting for 24 hours, which I have never seen before, then I know that something is amiss.

It will be interesting to see how long this battery will last with intermittent manual charging to full and desulfation. I'm betting I will get more than 10 years out of it. Time will tell.

 

[lorenfb]

We now KNOW that the LEAF battery charger only ever returns the battery to 100% charge on very rare occasions, if ever (and that it even depends on the weather!). Failure to return the SOC to full frequently is the long-known cause of lead-acid battery sulfation and is very likely the main reason that many LEAF 12V batteries have died well before their times.

That's your speculation! Again, please provide the data that indicate a high failure rate for Leaf batteries
besides anecdotal evidence. A simple graph depicting percent of sulfation as a function charging voltage
and time. It's as simple as that!

 

[BrockWI]

Two more cases of the 12v aux battery dying. The first one was while the vehicle was on and moving at 50 mph. For those of you that think this isn't a problem, great, then leave those of us who have experienced it first hand to figure out our problems.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=19767" onclick="window.open(this.href);return false;
and
http://www.mynissanleaf.com/viewtopic.php?f=30&t=19773" onclick="window.open(this.href);return false;

 

[RegGuheert]

The first one was while the vehicle was on and moving at 50 mph.

I do not think that one could be related to sulfation. If the battery were merely sulfated, then the vehicle would not have shut down while driving. The car was rather new, so I suspect that was probably caused by a shorted battery cell.

I do think your second link is related.

 

[AndyH]

Where are the actual capacity loss data, only voltage data have been presented without ANY current
measurements, e.g. load tests, Ahr measurements? Simple voltage measurements are NOT a valid
indication of capacity loss.

I'm very curious what some recommended tool(s) would be to get accurate capacity measurements.

I own and use a CBA pro with a 500W external load and a La Mantia analyzer (now Battery Metric). Either one can discharge and log battery performance and run automatic tests (like internal impedance) on the way down. The La Mantia box can recharge the battery after the test.

http://www.westmountainradio.com/cba.php
http://www.batterymetric.com/

 

[lorenfb]

Where are the actual capacity loss data, only voltage data have been presented without ANY current
measurements, e.g. load tests, Ahr measurements? Simple voltage measurements are NOT a valid
indication of capacity loss.

I'm very curious what some recommended tool(s) would be to get accurate capacity measurements.

I own and use a CBA pro with a 500W external load and a La Mantia analyzer (now Battery Metric). Either one can discharge and log battery performance and run automatic tests (like internal impedance) on the way down. The La Mantia box can recharge the battery after the test.

http://www.westmountainradio.com/cba.php
http://www.batterymetric.com/

Thanks for your input.

 

[69800]

The windshield wiper thing is an eye opener. I am suspecting when the load on the battery is such that the voltage drops to a certain value it kicks the charging voltage up to 14.1. I am going to do a test. I will find something to plug into the cigarette lighter that draws 15 amps. Using a dual port adapter I will have my wife watch the voltage each day with a load on and see if it will stay at 14.1 all day every day. I will report back as soon as I get some data. The other reason it would be nice to force the voltage up is on a dark nite. The halogen high beams lose about 25% of their lumens at 13.1 volt vs 14.1 volt. I could force maximum voltage and then my high beams would be brighter on a dark nite out here in moose and deer country. This would also give my battery a proper charge at the same time. Does anyone off the top of their head have and idea of an auto part device that would draw 10 to 15 amps? I will start the test immediately.

Update.

With everything turned on I can think of except the wipers I cannot get the voltage up to 14.1. Only the wipers will do it.