PPRuNe Forums - Search Results
PPRuNe Forums

Go Back  PPRuNe Forums > Search Forums
Reload this Page >

Search Results

Register
FAQ
Calendar
Wikiposts
Today's Posts
Search
Vendor Directory
 
Page 1 of 2
1
2
Search: Posts Made By: hetfield
Showing results 1 to 35 of 45
Search took 0.00 seconds.
Forum: Tech Log
6th Feb 2013, 13:59
Replies: 1,100
Views: 262,578
Posted By hetfield

755 must be a typo...

755 must be a typo...
Forum: Tech Log
6th Feb 2013, 08:40
Replies: 1,100
Views: 262,578
Posted By hetfield

@vince Welcome:) I really appreciate...

@vince

Welcome:)

I really appreciate your support.

About overcharging a single cell (1/48 cells), I'm with saptzae, it's voltage limited.

About a bad single cell (short) I'm fully with...
Forum: Tech Log
5th Feb 2013, 20:00
Replies: 1,100
Views: 262,578
Posted By hetfield

Boeing 787 batteries: What's causing their...

Boeing 787 batteries: What's causing their 'thermal runaways?' - CSMonitor.com...
Forum: Tech Log
5th Feb 2013, 17:27
Replies: 1,100
Views: 262,578
Posted By hetfield

Accident: ANA B788 near Takamatsu on Jan 16th...

Accident: ANA B788 near Takamatsu on Jan 16th 2013, battery problem and burning smell on board (http://avherald.com/h?article=45c377c5&opt=0)
...
Forum: Tech Log
5th Feb 2013, 12:28
Replies: 1,100
Views: 262,578
Posted By hetfield

Well, to my knowledge Li-Ion batteries aren't...

Well, to my knowledge Li-Ion batteries aren't that old...

Yes, but how can a charger/BMS look after the sub-cells?

They have their own social life. The rich feed the poor until dead.
Forum: Tech Log
5th Feb 2013, 11:01
Replies: 1,100
Views: 262,578
Posted By hetfield

I'm still concerned with the 6 sub-cells of each...

I'm still concerned with the 6 sub-cells of each of the eight cells.

They are never equal/matched perfectly. Current oscillations may occur, but even a totally unmonitored thermal runaway...
...
Forum: Tech Log
4th Feb 2013, 20:01
Replies: 1,100
Views: 262,578
Posted By hetfield

Which cells? 1/8 or 1/48?

Which cells? 1/8 or 1/48?
Forum: Tech Log
3rd Feb 2013, 21:51
Replies: 1,100
Views: 262,578
Posted By hetfield

@mm43 Thx, I know.... True, but...

@mm43

Thx, I know....



True, but irrelevant, negligible?

Don't think so.
Forum: Tech Log
3rd Feb 2013, 21:36
Replies: 1,100
Views: 262,578
Posted By hetfield

No! Eight packs a 65Ah, each consistent of 6...

No!

Eight packs a 65Ah, each consistent of 6 parallel connected cells.

To make clear, one single cell can't hold 65 Ah!
Forum: Tech Log
3rd Feb 2013, 20:48
Replies: 1,100
Views: 262,578
Posted By hetfield

@SoS So, no balancing of each of the 48...

@SoS

So, no balancing of each of the 48 cells, right?
Forum: Tech Log
3rd Feb 2013, 20:21
Replies: 1,100
Views: 262,578
Posted By hetfield

To put it simple... There are 48 cells in a...

To put it simple...

There are 48 cells in a 787 battery, right?

Eight "master cells" are balanced/monitored, right?

The sub cells are NOT BALANCED / NOT MONITORED, right?
Forum: Tech Log
3rd Feb 2013, 19:30
Replies: 1,100
Views: 262,578
Posted By hetfield

Thx mm43 That's very interesting. Looks...

Thx mm43

That's very interesting.

Looks like 6 sub-cells are put in parallel to a "master" cell of (1/8) 65 Ah.

Who/what is doing the internal balancing?
Forum: Tech Log
2nd Feb 2013, 13:33
Replies: 1,100
Views: 262,578
Posted By hetfield

Yes.. "Another fundamental architectural...

Yes..

"Another fundamental architectural change on the 787 is the use of variable frequency electrical power and the integration of the engine generator and starter functions into a single unit....
Forum: Tech Log
1st Feb 2013, 18:45
Replies: 1,100
Views: 262,578
Posted By hetfield

@Old Engineer Thx for the explanation:ok:

@Old Engineer

Thx for the explanation:ok:
Forum: Tech Log
31st Jan 2013, 09:11
Replies: 1,100
Views: 262,578
Posted By hetfield

It's amazing how proper balancing is done with...

It's amazing how proper balancing is done with these tiny wires.
Forum: Tech Log
30th Jan 2013, 19:02
Replies: 1,100
Views: 262,578
Posted By hetfield

Sorry, it's not about logging. It's...

Sorry,

it's not about logging.

It's about controlling/charging.
Forum: Tech Log
30th Jan 2013, 17:18
Replies: 1,100
Views: 262,578
Posted By hetfield

And my point is, do not put a BMS into a case...

And my point is, do not put a BMS into a case where a "thermal runaway" (Li-Ion) may happen...
Forum: Tech Log
30th Jan 2013, 16:19
Replies: 1,100
Views: 262,578
Posted By hetfield

@cockney steve What about the important BMS,...

@cockney steve

What about the important BMS, built by "Kanto Aircraft Instrument"?
Forum: Tech Log
30th Jan 2013, 16:01
Replies: 1,100
Views: 262,578
Posted By hetfield

Do T7 have Li-Ion batteries?

Do T7 have Li-Ion batteries?
Forum: Tech Log
30th Jan 2013, 15:50
Replies: 1,100
Views: 262,578
Posted By hetfield

SPOT ON! I fully agree.

SPOT ON!

I fully agree.
Forum: Tech Log
30th Jan 2013, 13:41
Replies: 1,100
Views: 262,578
Posted By hetfield

IMHO not a good place to put a BMS.

IMHO not a good place to put a BMS.
Forum: Tech Log
30th Jan 2013, 08:09
Replies: 1,100
Views: 262,578
Posted By hetfield

Yep, good question.:ok: I hope, it's not a...

Yep, good question.:ok:

I hope, it's not a design flaw....
Forum: Tech Log
30th Jan 2013, 07:47
Replies: 1,100
Views: 262,578
Posted By hetfield

@USMCProbe Have a look to the pictures. ...

@USMCProbe

Have a look to the pictures.
You will clearly see that the cells are put in serial. The thin wires at the joints come from the BMS which BALANCE charging current and monitor each cell....
Forum: Tech Log
29th Jan 2013, 18:53
Replies: 1,100
Views: 262,578
Posted By hetfield

Both E/E compartments on 787 are pressurized and...

Both E/E compartments on 787 are pressurized and air conditioned.

If the aircraft parks in Anchorage in the winter time for a prolonged period, well that's another story.
Forum: Tech Log
28th Jan 2013, 16:12
Replies: 1,100
Views: 262,578
Posted By hetfield

Whoever has to pay the bill...., no peanuts:\

Whoever has to pay the bill...., no peanuts:\
Forum: Tech Log
27th Jan 2013, 20:53
Replies: 1,100
Views: 262,578
Posted By hetfield

I'm afraid, no RC jockey would buy a LiPo battery...

I'm afraid, no RC jockey would buy a LiPo battery with this architecture for a 100 USD modell plane.
Forum: Tech Log
26th Jan 2013, 18:10
Replies: 1,100
Views: 262,578
Posted By hetfield

If this is the case, it's just poor engineering.

If this is the case, it's just poor engineering.
Forum: Tech Log
26th Jan 2013, 17:24
Replies: 1,100
Views: 262,578
Posted By hetfield

Exactly! Even the hobby RC guys doing...

Exactly!

Even the hobby RC guys doing better....
Forum: Tech Log
26th Jan 2013, 17:07
Replies: 1,100
Views: 262,578
Posted By hetfield

Thx Machaca. So, - "GS Yuasa" is the...

Thx Machaca.

So,

- "GS Yuasa" is the manufacter of the Li-Ion cells
- "Kanto Aircraft Instrument" deliver the "circuit boards",
- "Securaplane" the chargers (two different models)
- "Thales"...
Forum: Tech Log
26th Jan 2013, 09:31
Replies: 1,100
Views: 262,578
Posted By hetfield

There is no need for parallel charging if you...

There is no need for parallel charging if you have a battery management system (e.g. balancer etc.).

Lithium Battery Failures (http://www.mpoweruk.com/lithium_failures.htm)
Forum: Tech Log
25th Jan 2013, 01:28
Replies: 1,100
Views: 262,578
Posted By hetfield

True! Why? Revenue? Money? Who...

True!

Why?

Revenue?
Money?

Who got the balls to exlude Li-Ion on airplanes?
Forum: Tech Log
24th Jan 2013, 14:04
Replies: 1,100
Views: 262,578
Posted By hetfield

@A33Zab There were at least two fires on...

@A33Zab


There were at least two fires on UPS freighters with Li-Ion loaded.

One (747F) was a hull loss, both pilots died.
Forum: Tech Log
24th Jan 2013, 08:53
Replies: 1,100
Views: 262,578
Posted By hetfield

For those who never heard about Lithium...

For those who never heard about Lithium batteries, and if the RC guys are taking it seriously..........

Complete Guide to Lithium Polymer Batteries and LiPo Failure Reports - RC Groups...
Forum: Tech Log
24th Jan 2013, 08:29
Replies: 1,100
Views: 262,578
Posted By hetfield

@YRP You are right, my bad. NTSB, not...

@YRP

You are right, my bad.
NTSB, not Boeing visited securaplane.

BTW, just found this:
U.S. NTSB reviewing whistleblower claims in 787 case - chicagotribune.com...
Forum: Tech Log
23rd Jan 2013, 20:18
Replies: 1,100
Views: 262,578
Posted By hetfield

Yes, but this is just sugar for the public/press....

Yes, but this is just sugar for the public/press.

An individual overcharge MAY have occurred, 'cause every single cell (8) has to be charged and controlled seperatly. I'm afraid, this is not...
Showing results 1 to 35 of 45
 
Page 1 of 2
1
2


 
Forum Jump

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.