2012 Gen 1. Range stated as 229km SOH at Zero percent and 10 bars goes up to 12

I believe your observations of range/state of charge fluctuations along with the LEAF Spy screenshots are consistent with the one weak cell pair. I had a couple of weak cell-pairs showing up in my 2015 before I traded it in on the 2019 so I am familiar with the sudden drop in range/SOC. I never had the SOC bars increase while driving because there were always 12 showing after a full charge. As someone already posted, each module has 4 cells inside--two cells in parallel are considered a cell-pair and then two cell-pairs are connected in series. The three terminals provide a way to measure the voltage of each cell-pair since the center terminal is the center point of the series string. You should read about 4 volts from either end terminal to the center terminal and 8 volts between the end terminals.

You are correct that the 2011 and 2012 battery packs from Japan are easier to open because the case is bolted together with a reusable gasket. You can either buy the factory service manual or purchase an online subscription at https://www.nissan-techinfo.com/Home.aspx so that you have ready access to the necessary service instructions.

Thanks for your input Gerry. Thinking back... my LEAF never gave me more than about 70km on a full charge when using the highway or about 100km when taking back roads. I thought that that was normal. Going uphill or driving at highway speeds caused the range to fall drastically. Right now anything over 70 real km would seem great to me! Perhaps the battery has had a weak cell or cell pair from when I first bought it, in 2015 I think. I see you live in Phoenix. Did you get the upgrade to the 'lizard pack'? I have visited with my nephew in Gilbert and I know how hot it gets there.

Thinking back... my LEAF never gave me more than about 70km on a full charge when using the highway or about 100km when taking back roads. I thought that that was normal. Going uphill or driving at highway speeds caused the range to fall drastically.

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It's normal for a Gen I Leaf - especially if the 'water tank' heater is running in the background, using energy to preheat the coolant on cool days.

martincanuk said:

Thanks for your input Gerry. Thinking back... my LEAF never gave me more than about 70km on a full charge when using the highway or about 100km when taking back roads. I thought that that was normal. Going uphill or driving at highway speeds caused the range to fall drastically. Right now anything over 70 real km would seem great to me! Perhaps the battery has had a weak cell or cell pair from when I first bought it, in 2015 I think. I see you live in Phoenix. Did you get the upgrade to the 'lizard pack'? I have visited with my nephew in Gilbert and I know how hot it gets there.

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My experience in Phoenix: The original and replacement battery in the 2011 lost capacity quickly in the hot climate (original was down to 8 capacity bars after 2 years; Nissan replaced the battery and the replacement was down to 11 capacity bars when the car was totaled by someone who failed to stop for the traffic light I was already stopped at). The "lizard" battery in the 2015 did much better, but usable range was dropping rapidly due to a few weak cells by the time I traded it in. The larger battery pack in the 2019 is doing better than the previous cars after almost 2 years and over 30,000 miles of use. The heat is on with the predicted high of 115 degrees F next Tuesday.

What is 'coolant' used for in my LEAF? I wondered what the liquid filler tank in front of the 12v battery was for. I thought that the cabin heater worked by heating up a resistor but is that resistor residing in a water tank? Here in Sidney, BC the weather doesn't really have very low or very high temperatures so it's a favourable climate for a gen 1 LEAF. I obviously need to read more of the FSM on the excellent nicoclub website. I purchased a set of security bits yesterday after finding out the size and type of the screws that hold the plastic disconnect socket in place. Now I have to book time on a friends car lift so that I can get on with the job. It's a shame that my car has a weak battery composition because other than that it has been a very good car with a high SL 'luxury' spec. It still looks and drives like a new car. If only Nissan had designed it with a system for cooling the cells it would still be a very good car.

The coolant cools the motor, inverter, DC-DC converter (charges the 12V battery), and the onboard traction battery charger. On 2011 and 2012 models there is also a coolant loop with an electric water heater to provide cabin heat.

So Nissan thought about cooling everything but the battery pack. I've topped up the windshield washer a few times but nothing else because they never needed it. Brake fluid looks as clear as When it was new but I suppose it should be changed.

What is 'coolant' used for in my LEAF? I wondered what the liquid filler tank in front of the 12v battery was for. I thought that the cabin heater worked by heating up a resistor but is that resistor residing in a water tank?

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The Gen 1.0 does indeed use resistance heat to heat coolant. It is a problem because it does it almost all the time, unless you turn off the climate control. There was - and may still be - a heater control switch available through a member here for the Gen 1 Leafs. The Gen 1.5 leaf, introduced here in 2013 (but with the old battery chemistry retained until April of 2013 in the US) uses a direct to air resistance heater, and further incorporates a "heat" switch that turns off just the heater. A heat pump also became part of the system for higher trim models in 2013.

Hi LeftieBiker, I did think it unusual that I couldn't get fresh air blown through the vents when I first got the car unless I used the climate control. A switch to turn on the blower without the climate control would be most useful. Because of the limited range with my car I very rarely used the climate control as it was so power hungry. The only time that I really used it was when the windshield was fogging up and even then i would turn it off as soon as the glass was clear. Window fogging is the only pet hate that I have with the car. Do you know of a circuit diagram and where connections should be made for the switch mod? Back in 2002 I bought a new Toyota Prius. It was ugly but I liked the system and the 70mpg it could give me on a run. An owner of the same year color and model came to my house a couple of years ago. I asked him how many of the nicad packs the car needed over the years and he told me that it was the original one still going strong. My car then had a 10 year warranty on the battery which was about the size of three loaves of bread. I just checked on https://www.greencarreports.com/news/1078138_toyota-hybrid-battery-replacement-cost-guide where they say that the batteries can last for 300,000 miles! I might even go for a hybrid when my LEAF eventually dies. A new LEAF battery is in the 5 to 8 thousand dollars which is not something that I had considered because I don't usually keep cars for more than a couple of years. The LEAF is so good that I've kept it for what is its seventh year in my custody. It is a small battery in comparison with the new generation of cars and trucks so I wonder how much it will cost to replace one of the 100kw and even larger batteries in cars and trucks that are becoming popular.

Here is a link to a document that will help you. It includes a link to the heater switch mod:

https://mynissanleaf.com/viewtopic.php?f=38&t=23297&p=482154

Not all Prius batteries last that long. Many fail after about 10 years. And if you don't drive a lot, or only do short trips, the engines can become gummed up with oil residue. We had a Prius PHEV for 7 years, and traded it - with a sick motor - for a 62kwh Leaf lease.

LeftieBiker said:

Here is a link to a document that will help you. It includes a link to the heater switch mod:

https://mynissanleaf.com/viewtopic.php?f=38&t=23297&p=482154

Not all Prius batteries last that long. Many fail after about 10 years. And if you don't drive a lot, or only do short trips, the engines can become gummed up with oil residue. We had a Prius PHEV for 7 years, and traded it - with a sick motor - for a 62kwh Leaf lease.

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Prius are paragons on reliability and great value if you maintain them well. The only thing I have against them is the ICE

Well LeftieBiker your The Best, Least-Known Tips & Tricks kept me busy reading for hours last night. So many replies! My eyes are now sore from staring at the screen! What a wealth of information, most of which I didn't know and will find very useful. I intend to use the car only in the warm months of the year and the info of how to disable the A/C from running whilst using the blower is just what I needed. I will go for the simple method of bridging with a resistor. That is so easy to reverse when I decide to sell the car. Thanks a million.

Heh. You really only have to read the first post, but it can be hard to resist reading a whole topic. I need to add to the Gen II version of it, but I need more tips & tricks for them!