Skyblade:
Perhaps well written overall, but their mention that the forward battery is used to start the main engines seems ludicrous to me based on what I have read here and elsewhere.
The forward battery can be used to power the fuel metering and transfer system to allow partial refueling without engine, APU or ground power. But to start the main engines without ground power requires the APU.

And if I recall correctly, the "very high surge current rating of 1000A max.," is actually above the rating that Yuasa gives for the batteries.

I've learned more from other articles on the battery failures, nothing new here, just a rehash of known events albeit reasonably concise and non dramatic.

The best article IMO is here James Surowiecki: The Trouble with Boeing’s 787 : The New Yorker
This gets closer to the 'Root cause' than anything so far.

The refuelling system will only fuel up to 1500kg on battery power. This allows the APU to be started and refuelling can then continue.

[QUOTE]The world’s most modern aircraft in LOT’s livery took off today at 1:18 PM from the Warsaw airport to New York. This is the first transatlantic passenger flight of the LOT Polish Airlines Dreamliner after the three-month break. Thus, the Polish national carrier resumes scheduled transatlantic flights with Boeing 787 aircrafts.

The aircraft with the registration number SP-LRC with 205 passengers onboard is scheduled to reach the JFK airport in New York at 4 PM local time. The flight will last 8 hours and 8 minutes. [/QUOTE
Looks like an ETOPS flight straight away . With nearly full house. So confidence seems to be back , in Poland at least .

Reports from the Japan Times (3rd June 2013) that JAL has pulled a 787 fight due to a sensor issue related to the battery

JAL 787 is grounded by glitch in battery bay | The Japan Times

From a 19 May incident on a 787 which had just re-entered service

and now

Japan Airlines halts 787 flight after battery pressure sensor problem

What chance a quality installation of the fix ? I thought ETOPS certification was based on bullet-proof maintenance procedures. Not like these ones by the "fix team".

Japanese Pilots Worry About Repaired Boeing 787 Jets
 

Perhaps the pilots in Japan should be overseeing their nuclear power plants.

http://www.nytimes.com/2013/06/05/bu...-787-jets.html

Here's another Mitsubishi example of how simply dropping a Lion battery (during testing for example) can set the scene for thermal runaway. Something to be kept in the back of the mind, anyway.
Mitsubishi Motors recalls plug-in hybrids -NHK WORLD English-

Quote: "The maker has already suspended production of the 3 models.
Mitsubishi says the recall was triggered by 3 cases of batteries short-circuiting and melting. The company says its investigation found that some lithium-ion batteries had been accidentally dropped on the floor during testing.

The ministry says the batteries with damaged electrodes could short-circuit during charging, or even overheat and melt."

JAL has good reason to be sensitive about Boeing repairs. In 1985 JAL suffered worst loss of life in a single aircraft accident after Boeing botched repair of rear pressure bulkhead on a 747. See http://www.casa.gov.au/fsa/2005/aug/28-33.pdf. Long ago but many remember.

JAL Article
 

The article reports that JAL did the repair ( with Boeing supervision, whatever form that took ) and that JAL signed off on the repair.

JL operated the plane on test flights and at least one revenue flight (as the issue was discovered during a turn) so what did this JL flight crew / ground crew notice that the earlier JL flight crews / ground crews did not that led them to identify the tape still being on?

WAW-JFK is really not an ETOPS route unless some of the enroute diversion possibilities are unavailable due to weather.

RobertS975 : Thanks did not know. Can you explain ? looking at the tracks that day and the flight time , it really looked like it ( but I did not see the PLN).

Noticed on Flightradar24.com - Live flight tracker! ? the first ? Thompson 787 fly over us Manchester to Prestwick and that it's previous flights were Paine Field to MAN. Would that have been an ETOPS flight?

Japan B787 problems
 

Any new aircraft introduced into service WILL incur teething problems and the two in Japan are no exception. Let's not get carried away with trivial things and look at repeat problems instead (i.e. trend of a particular problem, such as Airbus pitot probes etc)):=

Yea right. :rolleyes:

787s were grounded and they are now flying again, but it is a probationary period and people will be interested in every little thing that occurs to see if any patterns might be emerging. People are still nervous in Japan. The press in Japan will pick up on anything, feeling it is in the public interest, whereas these incidents may not get reported in English.

Part of me wonders whether there is a reluctance in the English press to follow any further, whether they just want to give these new planes a break, or if there is some other force at play.

Anyway, in the interests of freedom of information I have given a rough translation of the two articles above. Personally I feel it is better to know what is happening up at the sharp end where the majority of Dreamliners are putting in the exploratory miles.

At the same time I agree that this thread concerns the electrics, specifically Lion battery performance, so if this is off-topic then point taken.

Probably not - but what's the global 777 fleet size compared to the 787? With Japan being the most prolific user of the type and with both public and pilots expressing concern/subjecting to scruitiny ANY event is going to be reported - and 2 (minor) events in two days on a fleet of 50ish aircraft resulting in a cnx and a turn back isn't great PR.

The problem is if there are multiple sensor/valve/switch events then questions start to be raised about quality. Is there not already history of nuts working loose causing minor scorching, misfit battery boxes/tape over sensors?

Correct A4. quality seems to be an issue indeed, but not surprisingly if you read the Seatle Times..

On a comparative note, if one looks at the MA-60, one can see that the FAA at least takes things seriously..
In China and Indonesia , the largest MA-60 operators, the aircrfat continues to fly despite a much worse record than the 787 : only 64 a/c in service , 7 accidents, of wich 3 in 2 months .
But to be fair , the FAA did not certify it..

Yeah, I've always considered airborne electrical fires trivial too!!

Are you serious?