Dead 12V battery question

My Nissan Leaf Forum

Help Support My Nissan Leaf Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Welcome. Aside from using refillable cells, it's a standard starting battery, type 51R. Many of us find that an AGM type battery works better with the Leaf than a standard starting battery, but you can use either. Remember: 51R, and the R, which indicates a different than usual terminal configuration, matters.

I'll be moving this post to an existing topic on this subject later.
 
I second the AGM but if the price is of utmost importance then a flooded acid or the regular auto 51R would also work. Some people also choose to go with a Li battery but they can be double the price of a AGM which is half again as much as the cheapest flooded acid battery. Li batteries also have issues in very cold climates, in MN I went with AGM and it's been working good for 5 years.
 
LeftieBiker said:
Welcome. Aside from using refillable cells, it's a standard starting battery, type 51R. Many of us find that an AGM type battery works better with the Leaf than a standard starting battery, but you can use either. Remember: 51R, and the R, which indicates a different than usual terminal configuration, matters.

I'll be moving this post to an existing topic on this subject later.

Interesting - thank you. I just checked the existing 12V battery in our Leaf, and the positive terminal is on the left side of the battery, which would suggest a 51 is correct for my model. I wonder why the difference?
 
The R designation doesn't appear to correlate with whether the positive terminal is on the right or the left. I just looked at a page of photos of 51R batteries, and the positive terminal appears both on the left and on the right, in relation to the front label, in them. I've never had to replace a Leaf battery, myself, despite having driven Leafs since 2013. I do remember a post in which someone described getting a 51 (no R) battery, and having one of the cables come up a bit short...

Actually, looking again, the + terminal is always on the right, but the front label isn't always on the same side, so the right terminal appears to be on the left for some batteries, even though it isn't. So, are you sure that yours is actually on the left?
 
Dtwhite said:
I need to replace the 12V battery of my (2016) Leaf. Is the 12V battery the very same acid type as is used in a standard petrol/diesel car, or a special type? In other words, can I just buy a regular off-the-shelf car battery, or do I need to get something specific? Thanks! The Leaf manual does not really say much about it.

Nope, just the obvious basics. It needs to fit and have the terminals in the right location. Easiest way is simply go to the battery store, plunk the old battery on the counter and say "got one?"
 
DaveinOlyWA said:
Dtwhite said:
I need to replace the 12V battery of my (2016) Leaf. Is the 12V battery the very same acid type as is used in a standard petrol/diesel car, or a special type? In other words, can I just buy a regular off-the-shelf car battery, or do I need to get something specific? Thanks! The Leaf manual does not really say much about it.

Nope, just the obvious basics. It needs to fit and have the terminals in the right location. Easiest way is simply go to the battery store, plunk the old battery on the counter and say "got one?"

…and that’s exactly what I did in the end. :D The replacement battery installed perfectly, and my Leaf is back in business.
Thanks to all for your advice!
 
The posts are not in the center of the battery--they are toward one side. The group 51R has the terminals reversed from the group 51. If you have the battery positioned with the terminals closest to you, the positive will be on your right with a group 51R. It will be on your left with a group 51. You can probably bend/form the wires to make either one work, but the 51R matches the OEM terminal arrangement (at least for 2011, 2015, and 2019). I replaced the OEM with an Optima deep cycle (yellow top) group 51R AGM battery in each LEAF I have owned.
 
I had my first 12V battery issue last week, at 35 months but 37K miles (so no chance of warranty coverage): the traction battery got super-low (turtle) and then would not accept a charge because the 12V battery was so low (with using wipers, heat, headlights) - we had to charge the 12V with cables in order to Level 2 charge. LeafSpy showed exactly 12V for the 12V battery but probably way less than that when the lights were on as we tried to charge. Anyway, AGM battery now and no looking back, sort of glad it was not to be covered by warranty and we would be stuck with another Nissan battery. LeafSpy now shows 13.04V..... Thanks to this Forum we knew that the issue would arise sooner or later and what to do about it.....
 
dmacarthur said:
I had my first 12V battery issue last week, at 35 months but 37K miles (so no chance of warranty coverage): the traction battery got super-low (turtle) and then would not accept a charge because the 12V battery was so low (with using wipers, heat, headlights) - we had to charge the 12V with cables in order to Level 2 charge. LeafSpy showed exactly 12V for the 12V battery but probably way less than that when the lights were on as we tried to charge. Anyway, AGM battery now and no looking back, sort of glad it was not to be covered by warranty and we would be stuck with another Nissan battery. LeafSpy now shows 13.04V..... Thanks to this Forum we knew that the issue would arise sooner or later and what to do about it.....

A bit confusing? The car is off and you have wipers, heat, headlights on? Or they were on when driving? FYI; wipers is a way to force charge the 12 volt which I do regularly especially during winter when voltages will be lower due to temperature.

FYI; that 13.04 is system voltage, not the battery. Normally a fully charged battery with a VERY light load (which exists all the time in the LEAF) will read no more than 12.7ish. I have started my car many times with voltage around 12 volts including a few at 11.9. I think its all a bit of random luck for the most part but also thinking the charging process probably uses a bit more current which could account for the inability to charge when it might be been possible to start the car?
 
Yes confusing- the car went into turtle and then stopped completely, I wish I had checked the 12V battery then but did not, towed it to a Level 2 (was tempted to try to charge while towing but lacked the cojones...) and that is when it would not charge the traction battery before a jump to the 12V. But as you say this could all be random. LeafSpy showed me 12.0V system voltage the day this all happened, now showing 13 plus, so evidently when system voltage gets below a certain point there is simply not enough juice to activate some of the chips.... putting the old 12V battery (the original, from 2019) on my old battery tester (the kind with the glowing resistance coil inside) the voltage drops to around 10.5.
 
When the car shuts down due to discharged traction battery (shortly after hitting Turtle mode), the car basically goes into accessory mode so auxiliary things like lights, radio, HVAC blower, wipers, etc. are being fed from the 12V battery. If the driver does not turn the car off, the 12V battery will soon be discharged low enough to be unable to close the main DC contactor after plugging the car in. Therefore, it is necessary to charge the 12V battery or use a booster battery to get charging started. Once traction battery charging starts, the DC-DC converter will charge the 12V battery while the traction battery is charging.
 
GerryAZ said:
When the car shuts down due to discharged traction battery (shortly after hitting Turtle mode), the car basically goes into accessory mode so auxiliary things like lights, radio, HVAC blower, wipers, etc. are being fed from the 12V battery. If the driver does not turn the car off, the 12V battery will soon be discharged low enough to be unable to close the main DC contactor after plugging the car in. Therefore, it is necessary to charge the 12V battery or use a booster battery to get charging started. Once traction battery charging starts, the DC-DC converter will charge the 12V battery while the traction battery is charging.

To add, my wife seems to be good at forgetting to charge and ignore all those dash warnings :lol:
Multiple times now, she has drained the 12V battery completely after main pack shutdown (well beyond turtle mode) because she left all the lights on, fans, seat heaters, etc. She has a Lithium 12V battery that will run for nearly an hour this way and still manages to discharge it completely. :x
As GerryAZ says, if you run your Leaf into complete main pack shutdown, pull over to a safe spot if possible and turn everything off to save your 12V battery. Unless you need to charge your cell phone or something, don't leave everything on and running accessory mode (fans, seat heater, wipers, lights, etc). It will make it harder to move or charge your Leaf later if it is "completely" dead on both the 12V and main battery pack. :shock:
 
knightmb said:
GerryAZ said:
When the car shuts down due to discharged traction battery (shortly after hitting Turtle mode), the car basically goes into accessory mode so auxiliary things like lights, radio, HVAC blower, wipers, etc. are being fed from the 12V battery. If the driver does not turn the car off, the 12V battery will soon be discharged low enough to be unable to close the main DC contactor after plugging the car in. Therefore, it is necessary to charge the 12V battery or use a booster battery to get charging started. Once traction battery charging starts, the DC-DC converter will charge the 12V battery while the traction battery is charging.

To add, my wife seems to be good at forgetting to charge and ignore all those dash warnings :lol:
Multiple times now, she has drained the 12V battery completely after main pack shutdown (well beyond turtle mode) because she left all the lights on, fans, seat heaters, etc. She has a Lithium 12V battery that will run for nearly an hour this way and still manages to discharge it completely. :x
As GerryAZ says, if you run your Leaf into complete main pack shutdown, pull over to a safe spot if possible and turn everything off to save your 12V battery. Unless you need to charge your cell phone or something, don't leave everything on and running accessory mode (fans, seat heater, wipers, lights, etc). It will make it harder to move or charge your Leaf later if it is "completely" dead on both the 12V and main battery pack. :shock:

There is NO reason whatsoever to hit main pack shutdown. You have warnings well before that happens and waiting is simply idiotic.
 
GerryAZ said:
... Therefore, it is necessary to charge the 12V battery or use a booster battery to get charging started. Once traction battery charging starts, the DC-DC converter will charge the 12V battery while the traction battery is charging.
On my 2011 LEAF, I recently observed that while L2 charging the main pack, that if the LEAF is ON, the DC-DC converter is inactive and NOT available to charge the 12V battery while the traction battery is charging.

I only discovered this because I left the LEAF ON to keep the 12V auxiliary outlet powered for charging my cell phone that had LEAF Spy Pro running creating a graph of the pack charging that I planned to Save.

I only discovered the situation when I turned the windshield wipers on to have the LEAF DC-DC raise the 12V buss voltage to check the 12V battery completeness of charge and saw that the buss voltage did not change.

Turning the wipers on is a simple way to fully charge the 12V. With my AGM you know it is pretty fully charged once the current with 14.2 V on the buss drops very low to 0.86 or 0.67 amps.

I had done a similar thing a lot while using DCQC. And with DCQC charging the pack and the LEAF ON the DC-DC is active. But on my 2011 it is NOT while doing L2 with the LEAF ON.

There are also differences on HVAC availability with LEAF ON between DCQC and L2. HVAC works with DCQC, but usually NOT with L2.

One last note on killing the 12V. I killed it once with the headlights turned ON. With the headlight relay closed and 12V buss voltage very low, took a stout 12V source to be able to get the headlight relay to open.
 
Turning the wipers on is a simple way to fully charge the 12V.

Yes, although to be clear to newbies, you have to either leave the wipers on, or keep tapping the wiper lever every few minutes, because the boost to 14+ volts only lasts about a minute. One way around this is to put them on Intermittent, and adjust the interval to the longest setting.
 
My 2011, 2015, and 2019 all act the same way. HVAC and DC-DC converter function normally while car is charging on L2 or DCQC as long as SOC is at least 25%. HVAC will not function while charging if charge level is below about 25%. You must have SOC above 25% and have foot on brake before pushing start button if you want HVAC to function while charging. If SOC is less than 25%, you need to turn car off and then turn it back on with foot on brake after SOC gets above 25% to activate HVAC. I don't know what mode Tim Lee had his car in to cause the DC-DC converter to be off while the car was charging (possibly accessory mode).
 
TimLee said:
GerryAZ said:
... Therefore, it is necessary to charge the 12V battery or use a booster battery to get charging started. Once traction battery charging starts, the DC-DC converter will charge the 12V battery while the traction battery is charging.
On my 2011 LEAF, I recently observed that while L2 charging the main pack, that if the LEAF is ON, the DC-DC converter is inactive and NOT available to charge the 12V battery while the traction battery is charging.

I only discovered this because I left the LEAF ON to keep the 12V auxiliary outlet powered for charging my cell phone that had LEAF Spy Pro running creating a graph of the pack charging that I planned to Save.

I only discovered the situation when I turned the windshield wipers on to have the LEAF DC-DC raise the 12V buss voltage to check the 12V battery completeness of charge and saw that the buss voltage did not change.

Turning the wipers on is a simple way to fully charge the 12V. With my AGM you know it is pretty fully charged once the current with 14.2 V on the buss drops very low to 0.86 or 0.67 amps.

I had done a similar thing a lot while using DCQC. And with DCQC charging the pack and the LEAF ON the DC-DC is active. But on my 2011 it is NOT while doing L2 with the LEAF ON.

There are also differences on HVAC availability with LEAF ON between DCQC and L2. HVAC works with DCQC, but usually NOT with L2.

One last note on killing the 12V. I killed it once with the headlights turned ON. With the headlight relay closed and 12V buss voltage very low, took a stout 12V source to be able to get the headlight relay to open.

Which battery technology, i.e. a flooded lead acid or an AGM, requires the higher charging voltage? Can you provide a link and supporting data?

Here's one; https://www.alpha-batteries.co.uk/blog/a-detailed-guide-to-agm-batteries/

Most Caravans and Motorhomes up until 2017 come factory fitted with non-AGM charging systems and to make things worse some manufacturers will state that they ‘may be suitable’ for charging AGM batteries – they simply aren’t, but why? If you take a look at the datasheets and technical specifications for AGM batteries on our website, you will see that we publish specific charge settings and this ultimately centres around voltage. AGM batteries are designed to require 14.6v – 14.8v when performing a full charge from a state of discharge, whereas standard lead acid batteries need 13.8v – 14.4v, hence this is what most onboard chargers are designed to deliver – not the 14.6v – 14.8v that AGM requires.

Based on the above and what is known about the typical Leaf battery charging voltage (14.2V), it appears that the Leaf provides an inadequate AGM charging voltage.

Are there conflicting data to the above link? My original 2013 Leaf 12V battery lasted until 2020,
so I see little value in an AGM battery for my 2019. Besides anecdotal data, what're the bases'?
 
I use a couple different AGM battery manufacturers for my vehicles: I replaced the Nissan OEM battery in each LEAF with an Optima yellow top D51R. In each case, the Nissan OEM flooded cell battery failed after 2 to 2-1/2 years (which is actually longer than typical for OEM batteries in gas engine vehicles in my climate). Optima recommends float voltage of 13.2 to 13.8 and alternator output voltage of 13.65 to 15.0 for their yellow top deep cycle batteries. My experience with Optima batteries (red top starting batteries and yellow top deep cycle/starting batteries) is that overcharging kills them prematurely in the hot dry climate where I live. They last far longer than other batteries as long as the alternator output voltage on a vehicle is not too high. The DC-DC converter output on the LEAF is ideal for long life of the Optima batteries because it is 14 to 14.5 volts until absorption current drops and then switches to float voltage of about 13 to 13.5 volts (both voltage levels are temperature compensated so higher when cold and lower when hot) to avoid overcharging. I use Odyssey batteries in motorcycles, Jet Skis and a Group 65 in my SUV (since Optima does not make Group 65 size). They have about the same charging voltage recommendations.

I switched to AGM batteries after getting tired of cleaning up corrosion around flooded cell batteries and having even top-of-the-line flooded cell batteries fail after 6 to 18 months.
 
Back
Top