My Nissan Leaf Forum

I have a simpler procedure. Take it out on the freeway at 70mph and it will only take 60 minutes at most to get down to 2 bars or less.

Two new Bars, or two Old-Bars?

There is about a 1.4 bar difference. Two full New-Bars (possibly in the April 2011 Service Manual) is about 1.7 bars over LBW, whereas two full Old-Bars (would be used in the original Fall 2010 Service Manual) is only about 0.3 bars above LBW.

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Discharging (at roughly L2 rates) before the test, and using L2 after the test to get the customer's car recharged (enough to get home safely), can make this Cell-Diagnostics test take 6 or more hours.

If one lives close to the dealer, arriving with the "required" low readings, and being able to get back home on the remaining 2 bars ... would be optimal for timing.

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Doing the test at low battery would usually make a "bad" cell-pair more obvious, but more-or-less assumes that the Pack is well Balanced.

Doing the test near FULL would check how effectively the Pack balancing was being accomplished.

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We need to log (low profile, or with a sympathetic dealer) the EV CAN bus during this Diagnostic so that we can attempt to find out how one (we) could "request" the cell-pair voltages.

Yes. My recommendation is to charge the night before to only 80%, if you're going to be going to the dealership directly in the morning. Unless, of course, you can't make it there on only 80% charge!

Just FYI, as the original poster of this thread, my dealership is only about 7 miles from my house and since I took city streets instead of the highway to get there my Leaf was actually reading 100% charge and 105 miles of range when I arrived.

Whenever I get another chance to go, I'll run the car down to three bars and then head towards the dealer, hoping to make it to 2 bars when I arrive. As long as they charge it for 30 minutes or so, it should be a very worry-free ride home. The only disadvantage is that my car will be drained and won't be able to plan any longer trips for that day until a full recharge.

I'm expecting this kind of confusion when I take my car in a week from now for its annual test. I asked if the car needed to be at a particular SOC, and they said no. Then they told me that there was no battery test needed, but if I insisted, they would hook up the Consult diagnostic unit. What'll you bet that they try and charge me for the service?

I told them that the owner's manual and warranty manual clearly state that annual battery tests are required in order to keep the battery warranty in effect. To be fair, my LEAF will probably be the first one that has come in for the battery test; it was only the second LEAF that they sold.

Looks like I'll have to rent a car dolly. I could drive the LEAF down to Palmdale, but then I'd be stranded without a car until the next day. Too bad; the 85 mile drive down would guarantee that I'd arrive with a low SOC.

-Karl

Good reason for dealers to have QC.

The OP's dealer probably doesn't understand the procedures. Given a requirement that a customer arrive at the dealer with only two bars of charge is absurdly onerous, it's very hard to believe that Nissan doesn't have a procedure for testing batteries at all SOCs. My guess is we don't hear about this again.

Gary,

The SM I have says 2 bars wich I suppose are old bars. What is more important is that it mentions to discharge the battery until the lowest cell pair reads 3,712V. For a perfectly balanced pack this is 356,4V wich is the voltage that my car has when it reaches LBW. This is were the knee of the voltage starts and makes it a lot easier to see unbalanced/damaged cells.

This has been an illuminating discussion, but I think the obvious conclusion is that the required annual battery report is not the same as the CELL VOLTAGE LOSS INSPECTION. Here is what the Warranty Information booklet says:

See? They don't even call it an inspection. It sounds to me like it is just a log readout. That could be done at any charge level. Now maybe the OP specifically asked for an inspection or test, or maybe the service department misunderstood the warranty requirement, but the bottom line is that the annual report has no onerous requirement but probably won't tell you much. I expect we will hear about this "2 bar" inspection again, but only in the context of a battery which is acting up.

Ray

this makes sense