Strike One!

February 21, 2014

Mark D Larsen

Losers, Weepers
(click to enlarge)

Alas...! My Leaf has lost its first capacity bar. Yes, I knew it was inevitable, but I nonetheless feel a melancholic sense of loss.

Yesterday, after descending the hill from our home, I happened to glance at my gauges, and noticed that the charge bars were only one below the capacity bars, even though I had charged to the usual 80% overnight. On one previous occasion, I had witnessed regenerative braking actually add a bar to the display, and assumed that such a rare occurence had happened again, perhaps because of the warmer weather. This afternoon, however, shortly after leaving home, I noticed the same readout again, and it dawned on me that it wasn’t showing an extra charge bar at all, but rather... a missing capacity bar! I pulled over to the curb, counted all the bars to make sure, and snapped the photo at the top of the page. That capacity bar thus gave up the ghost 694 days and 16,608 miles after I took delivery.

So what is my Leaf’s current battery capacity? In truth... I am not sure. A Nissan Leaf Service Manual reportedly states that the first bar represents 15% of the original capacity, and the subsequent bars 6.25% each. Unfortunately, those numbers just don’t add up: 15% + (6.25% x 11 bars) = 83.75% —not 100%. So where is the missing 16.25% capacity? Such percentages make no sense.

I have repeatedly asked a few contacts at Nissan about that discrepancy, but have yet to receive a definitive answer from any of them. I have even provided them with the following annotated photos to clarify the problem. You can see in the one on the left that the 15% minus subsequent 6.25% formula just doesn’t work.

Unequal Bars
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Equal Bars
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For this reason, I have often wondered if perhaps that service manual is simply wrong, and the capacity is actually distributed among the bars equally: 100% / 12 = 8.3334% each. If so, the corresponding percentages would resemble the photo above on the right instead. Regardless, in either case, Nissan’s new capacity warranty would kick in at comparable percentages: losing the crucial fourth bar would indicate about 66% of remaining capacity (the red threshold in the photos), so perhaps the precise value of each individual bar is a moot point.

It nonetheless begs the question: will I lose that fourth bar before the capacity warranty expires? At the rate my Leaf’s months and miles are accumulating to date, my guess at this point is that I won’t. Only time will tell. Stay tuned: I will post subsequent reports as more bars disappear from the dashboard.