bATT LOW SEE MANUAL

My 2011 Honda Odyssey, Sam (named after Samuel Clemens, Samwise Gamgee, and Samantha Stewart, a character in Foyle's War) has been a big step up from my 1996 Plymouth Voyager. They're both 6-cylinder minivans, but the 2011 Odyssey is larger, more powerful, and gets much better highway MPG. (If the Odyssey were any larger, I'd need to remodel my garage after the Tardis -- larger on the inside than the outside.) There are plenty of gadgets and interfaces as well, but that's not the point of this short post.

All first-year redesigns have teething problems. Consumer Reports advises against buying freshman models for this very reason. In my case, and many others commiserating on the web, there is an annoying problem with the battery management system (BMS).

Mind you, I've never had a car before that would warn me when the battery was getting low. The first symptom would either be a hesitant engine start, or the dreaded machine gun click-click-click of an exhausted battery. So I'm not against a battery management system! But this one has a hair-trigger, and you can't ignore it. It's not a meek idiot light, so thank goodness it doesn't go on forever.

You can imagine how startled I was the first time that warning flashed! I took Sam to the dealer on Jan. 19th, who checked the battery (nothing wrong), cleaned and tightened the negative terminal, and cleared the error. Blessed silence ensued for the next 2½ weeks; then, the warning returned.

A simple Google search revealed that I was not alone, and that most with this symptom did not have real battery problems. We speculate that it's an issue with the sensitivity or monitoring mechanism or programming of the BMS. I took Sam into the dealer again, who told me that they had just been informed by Honda to "inspect" any Odyssey reporting this problem. Sam's work ticket from Feb 9th states,

Called Tech line, sent me a fax of a questionaire to fill out, looked up specs with HDS, hooked up GR8 and ran diag on battery, unplugged connector on battery, faxed all papers to ahm.honda.com.

So Honda is collecting engineering data. Meanwhile, I must be patient while waiting for a fix. Today, on schedule, about 2½ weeks after the last reset, the dreaded bATT LOW has returned.

 I'm hopeful that as the weather warms up the BMS will be less twitchy.

Update 04/29/2011

Today I received two notices from Honda. Neither one of them is regarding the Battery Management System.

The first is a Product Update for the audio unit software addressing a software bug that can affect the clock, radio, and HandsFreeLink. I haven't noticed anything in this area. The update is low-key: the letter mentions scheduling is as part of your 'next planned service appointment.'

The second is an Important Safety Recall Notice for the front windshield wiper arms. They're too flimsy. If the blades are frozen to the windshield and you turn on the wipers, the arms may bend or separate!

I'm still waiting for any word on the Battery Management System. Since I took a long road trip in March, and the weather warmed up, I haven't seen the problem again. Left unresolved, I'm sure it will show up again next winter.

Update 05/19/2011

It's baaaack! After being away for 15 days or so, I fired up Sam last evening, and got the bATT LOW message. Perhaps a little freeway driving and a warmup (it has been chilly this week) will help, at least temporarily.

Update 12/17/2011

Honda has finally released a TSB (Technical Service Bulletin) for a product update on this issue! Hurray!

Honda TSB 11-073 - Product Update: MID Shows BATTERY CHARGE LOW or bATT LOW 

Applies To: 2011 Odyssey – Check the iN VIN status for eligibility 

BACKGROUND

The battery sensor software update improves the accuracy in warning customers when the battery’s state of charge is low by changing these inputs:

• The sensor factors in the ambient temperature when calculating the current state of charge.

• The sensor ignores short duration voltage drops, such as when the power sliding doors are opened.

A low battery message may still appear if the customer uses a system for an extended period of time with the engine off, such as playing a movie on the RES or planning a trip using the navigation system.
The new software will not improve vehicles with the following conditions:

• The vehicle has a low battery because it’s not driven regularly or long enough to recharge the battery.

• There is a high-current draw problem with the vehicle, such as a high parasitic draw caused by aftermarket accessories (alarms, video game systems, etc.). 

CUSTOMER NOTIFICATION

All owners of affected vehicles will be sent a notification of this product update.

Update 01/15/2013

I had the software update applied a month ago -- I waited a long time so that I could take it in at the same time as Sam's annual oil change. I'm pleased to report that I'm now free of the dreaded chimes!