BMS Reset ?

[peepsann]

Hello Leafers,

I purchased a 2011 Nissan Leaf SL 4 months ago with 9 bars...within 1 week I lost one bar and it went to 8...8 was still working for me, but as of yesterday and less than 4 months after going to 8 bars..I am now at 7.... 7 bar range is not going to cut it for me....is it safe to assume that going from 9 bars to 7 in less than 4 months and 800 miles, that my car had it's BMS reset ?? Note : I charge at home with level 2 and only to 80%..I only discharge to 20 % and I reside in Southern California.... I am concerned this degradation is in an accelerated state and frankly I don't know why. Nissan dealer wants $9500 after tax to replace the battery...I am not sure I really want to invest that kind of money in a 2011 car, though it only has 50,000 miles on it and is in excellent condition other than it's battery..I have $5800 invested in this entery level EV car so far, so not that much.... Even so, and that said, I am really liking the EV thing....but this battery issue is a major set back...I have considered purchasing a newer Leaf...2016 -2017....But I am concerned with a repeat of my 2011's rapid battery degradation....and should I be ?

 

[WetEV]

Hello Leafers,

I purchased a 2011 Nissan Leaf SL 4 months ago with 9 bars...within 1 week I lost one bar and it went to 8...8 was still working for me, but as of yesterday and less than 4 months after going to 8 bars..I am now at 7.... 7 bar range is not going to cut it for me....is it safe to assume that going from 9 bars to 7 in less than 4 months and 800 miles, that my car had it's BMS reset ?? Note : I charge at home with level 2 and only to 80%..I only discharge to 20 % and I reside in Southern California.... I am concerned this degradation is in an accelerated state and frankly I don't know why. Nissan dealer wants $9500 after tax to replace the battery...I am not sure I really want to invest that kind of money in a 2011 car, though it only has 50,000 miles on it and is in excellent condition other than it's battery..I have $5800 invested in this entery level EV car so far, so not that much.... Even so, and that said, I am really liking the EV thing....but this battery issue is a major set back...I have considered purchasing a newer Leaf...2016 -2017....But I am concerned with a repeat of my 2011's rapid battery degradation....and should I be ?

The 2011 to mid 2013 battery was the worse that Nissan has made. I own a 2014 Leaf SL with all twelve bars in a cooler climate. 2015 Leafs are better.

The bars are a reflection of the state of the battery and not the actual state of the battery. Resetting the BMS (if that's what happened) does not give you more range, and losing bars after a reset does not lose actual range. The battery still stores the same amount of energy. Changing driving and charging habits can change the BMS's opinion, perhaps enough to lose a bar or two.

I'd suggest charging to 100% assuming you can do so soon before departure, and driving the car until you actually lose enough capacity to care, and then revisit the question.

 

[GerryAZ]

Capacity bars are reasonable for a 2011 so I doubt that the lithium battery controller (LBC or BMS) was inappropriately reset. I also suggest that you charge to 100% and use the car until range becomes an issue. In addition, I recommend that tires be inflated to 44 psi for improved handling, reduced rolling resistance, and longer tread life (compared to Nissan's recommendation of 36 psi). I also recommend that you obtain Leaf Spy Pro and a suitable OBDII adapter to have more accurate state of charge and remaining range information. There is significant range remaining after low battery warning (LBW) and very low battery warning (VLBW). I typically get at least 7 miles between LBW and VLBW and another 7 miles after VLBW.

I have always charged to 100% and there was no noticeable difference in capacity loss of my 2011 compared to others in my climate that were only charged to 80%. 2014 and later cars do not have the 80% charge option in the charge timer settings so my 2015 is also always charged to 100%.

 

[LeftieBiker]

The capacity bar reading is now what I'd expect for a 2011, but the rate at which they have been dropping strongly suggests a BMS reset. Try to get the dealer to take the car back. Don't assume the dealer did it, as it may well have been done at auction. If you bought it privately, though, the owner probably did it.