PPRuNe Forums - View Single Post - 787 Batteries and Chargers - Part 1
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Old 25th Feb 2013, 21:51
  #812 (permalink)  
cockney steve
 
Join Date: Jan 2008
Location: lancs.UK
Age: 72
Posts: 1,196
I'll just reiterate what i posted l ooo ooo ng ago.

place each sub-cell in an insulating ceramic pot (which could have a screw-on lid in the same material.

Make the cell-tails from heat- sensitive alloy
fit each one with a temp-probe and voltage-monitoring wire.
place all three in a second fireproof ceramic pot.

The main terminals each have a busbar to which the tails are attached.
each subcell individually monitored,so much tighter control. any high current or overheating will melt the tail (fusible link) thus disconnecting the individual sub-cell. THE BATTERY WOULD MAINTAIN IT'S AVAILABILITY (unless all 3 sub-cells in a single-cell failed O.C.

Thermistors cost buttons-even "certified "ones should be well affordable within the current 16,000 dollar postulated ripoff price.

Controller/memory/discrete components are all pennies and there is no earthly reason why 48 temp and 25 voltage wires should present a problem to the control/monitoring/charging unit.

It seems no-one is willing to lose face by admitting this fitment was ill-thought-out and piss-poorly executed.

PROPERLY engineered, I'm sure the initial objectives could be met and the fusing/monitoring/insulating (heat, as well as electrical) regime would probably allow a thinner,lighter containment-vessel (sorry, "container")
Fingers crossed they rejig the charging/monitoring wherein I feel the problem lies. They're determined to stick with the technology, they HAVE to respect it's limitations and keep within the SAFE operating envelope.
@Smilin' Ed.
They threw KISS out the window and sacrificed safety on the altar of weight reduction.
Unfortunately, the sodding great tin fire- box added back all the weight .

not to mention the cost of this fiasco ,to both finances and reputation.

Perhaps, the engineers KNEW but were overruled by arrogant "suits" "know it all all. Perhaps it was a genuine oversight or omission and nobody recognised the importance of a building burning.......et al.
cockney steve is offline