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| Thread ID: 129070 | 2013-01-31 20:55:00 | Dreamliner's Li-ion batteries | BBCmicro (15761) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1325835 | 2013-01-31 20:55:00 | Interesting discussion here: www.eeweb.com As I understand it, the investigators have determined that the cell design is fine and so is the charging system. The remaining component is the Battery Management System (BMS) which is what the link discusses |
BBCmicro (15761) | ||
| 1325836 | 2013-01-31 21:02:00 | Do they really need Lithium batteries? They should stay with tried and trusted aircraft nicad batteries the weight savings cant be that much. The batteries aren't that big they only have to start the APU, supply enough power to activate fuel valves when refuelling when APU not running and for quadruple redundancy for critical instruments and radio. The difference in weight would probably be no more than carrying a fat pax than a thin one. | prefect (6291) | ||
| 1325837 | 2013-01-31 22:49:00 | More on the saga ... NTSB-Boeing-787-battery-shows-short-circuiting (www.komonews.com) and ANA-say-787-batteries-replaced-up-to-10-times (news.msn.com) Prefect, weren't the early ni-cads susceptible to exploding? I seem to recall a couple of Lears disappearing off the radar in the States, the result of an inflight explosion, but I can't find anything on those. |
WalOne (4202) | ||
| 1325838 | 2013-02-01 00:04:00 | I wish I had a battery management system that would make sure my re chargeable AA's are charged properly. | Digby (677) | ||
| 1325839 | 2013-02-01 00:20:00 | Do they really need Lithium batteries? They should stay with tried and trusted aircraft nicad batteries the weight savings cant be that much. The batteries aren't that big they only have to start the APU, supply enough power to activate fuel valves when refuelling when APU not running and for quadruple redundancy for critical instruments and radio. The difference in weight would probably be no more than carrying a fat pax than a thin one. My understanding is it's all to do with weight and efficiency. Efficiency is one of Boeings big selling points on the Dreamliner, making it a "next generation" plane. |
Alex B (15479) | ||
| 1325840 | 2013-02-01 00:27:00 | More on the saga ... NTSB-Boeing-787-battery-shows-short-circuiting (www.komonews.com) and ANA-say-787-batteries-replaced-up-to-10-times (news.msn.com) Prefect, weren't the early ni-cads susceptible to exploding? I seem to recall a couple of Lears disappearing off the radar in the States, the result of an inflight explosion, but I can't find anything on those. Yes you can get Ni Cad thermal runaway where as the battery gets hotter the resistance goes up and the battery gets hotter till it sort of explodes. But something has to set it off either a massive load like a direct short or charged at full rate from discharged which normally happens on the ground. Pretty rare event now days and is survivable seen it on a helicopter. |
prefect (6291) | ||
| 1325841 | 2013-02-01 00:28:00 | My understanding is it's all to do with weight and efficiency. Efficiency is one of Boeings big selling points on the Dreamliner, making it a "next generation" plane. But the quest for efficiency should not lead to CBD (crash burn die) I would just swap a fat pax with a thin one to make up the weight diff. Been thru this saga before with 211 fan blades. |
prefect (6291) | ||
| 1325842 | 2013-02-01 02:39:00 | Yes I saw a clip on tv of one of the 787's on the assembly line showing an open fuselage second. And boy the walls looked THIN ! to my untrained eye I have tried to find out How big are those batteries ? How much does one weigh ? How many on the plane ? |
Digby (677) | ||
| 1325843 | 2013-02-01 03:47:00 | I think the main benefit of the Lithium cells is the ability to recharge them independent of the charge state, nicads had to be run down. Also I believe they have a longer life expectancy (except when they catch fire :rolleyes: then everyone has a lower life expectancy) It's not a fault of the type, its a fault of the manufacturer. You carry around lithys in your pocket and have them on your lap, no danger. Heck, some people drive cars with them and those are bigger cells than the ones in the 787. I think Boeing needs to have words with lot that make the cells and sort them out. |
The Error Guy (14052) | ||
| 1325844 | 2013-02-01 06:46:00 | More on the saga ... NTSB-Boeing-787-battery-shows-short-circuiting (www.komonews.com) and ANA-say-787-batteries-replaced-up-to-10-times (news.msn.com) Prefect, weren't the early ni-cads susceptible to exploding? I seem to recall a couple of Lears disappearing off the radar in the States, the result of an inflight explosion, but I can't find anything on those. Found a aviation report (www.ntsb.gov) (pdf) from NTSB (www.ntsb.gov/) of a Gates Learjeat that crashed due to explosion from gas fuel and nicads. |
kahawai chaser (3545) | ||
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