Today's Message Index:
----------------------
1. 03:29 AM - Re: lithium facts (Jan de Jong)
2. 07:05 AM - What tool do you use to crimp these? (Jeffrey W. Skiba)
3. 08:09 AM - Re: What tool do you use to crimp these? (Stein Bruch)
4. 02:06 PM - Re: Ammeter going haywire (Bill Bradburry)
5. 07:42 PM - Re: Ammeter going haywire (Robert L. Nuckolls, III)
Message 1
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| Subject: | Re: lithium facts |
On 11/5/2014 9:22 PM, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
> At 12:46 2014-11-05, you wrote:
>> <jan_de_jong@casema.nl>
>>
>> Well, all I can say - I'm amazed.
>> I wonder why I never read anything anywhere but 3.6V to 3.7V - with
>> dire warnings about exceeding much...
>>
>> By the way, these people show 90% charge at 3.6V (100% at 4.2V):
>> http://www.powerstream.com/LLLF.htm
>
> Check out this page . . .
>
> http://tinyurl.com/2349lq2
>
> and the links cited thereon. Isidor Buchmann is
> about as knowledgeable as they come about batteries
> exceeded only by his generosity for sharing what
> he knows.
>
>
> Bob . . .
>
Interesting.
It remains difficult to know when generic "Li-ion" data applies and when
specific data is needed for one of the cathode chemistries: "LCO",
"LMO", "LFP", "NMC", "NCA", "LTO"
see
http://batteryuniversity.com/learn/article/types_of_lithium_ion
http://batteryuniversity.com/learn/article/lithium_based_batteries
What I am guessing at the moment:
- the aging mechanisms and lifetime statistics are similar
but some are more robust than others
- the maximum cell voltage (4.2V) applies to all
- charging method and charging phases are similar
but they have different capacity vs. final charging voltage curves
charging LFP beyond 3.6V doesn't add much, charging LCO beyond 3.8V
to 4.2V adds most of the charge
see http://www.powerstream.com/lithuim-ion-charge-voltage.htm
(the average force required to get an ion into a crystal location is
different)
- they have different (slow) discharge voltage curves (LFP flat at about
3.2V, LCO steadily decreasing from 3.9V)
I could be wrong.
Jan de Jong
Message 2
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| Subject: | What tool do you use to crimp these? |
What tool do you use to crimp these?
DQo
DQoNClNlbnQgZnJvbSBteSBpUGhvbmU
Message 3
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| Subject: | What tool do you use to crimp these? |
Those are affectionately referred to as "flag terminals", so if you have a
ratcheting crimper with removable jaws, sometimes you can get a set of jaws
for flags, otherwise do a quick google for flag terminal crimper and you'll
find lots of options. That said, if you are careful (and depending on the
brand of flag terminal), sometimes you can use a regular terminal crimper
for them with good success.
Cheers,
Stein
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jeffrey
W. Skiba
Sent: Thursday, November 06, 2014 9:04 AM
Subject: AeroElectric-List: What tool do you use to crimp these?
What tool do you use to crimp these?
Message 4
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| Subject: | Ammeter going haywire |
Bob,
I am pretty sure that it is reading battery charge current. It is too low
to be alternator output or load I think.
He had been doing some work on the engine and had run the battery down
considerably trying to start it. On the next flight the amps jumped up to
8 on start then gradually reduced to about 4 by the end of the flight. The
next flight the amps jumped up to 4 on start then came down to about 2.5 by
the end of the flight.
Somewhere in here his mechanic told him he needed a new battery so he
replaced the battery.
The next flight with the new battery the amps jumped up to about 4 on start,
then dropped to about 2 amps for about 10 minutes then started the gradual
climb to 9 amps over the next 40 minutes.
The next flight the amps jumped to about 3 on start then dropped to about 2
for 10 minutes then slowly climbed to over 4 amps for the next 40 minutes or
so.
This now seems to be the standard.
Any ideas would be welcomed.
Bill
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
McCallum
Sent: Wednesday, November 05, 2014 11:56 PM
Subject: RE: AeroElectric-List: Ammeter going haywire
First question is what current is this ammeter reading ?? Alternator output
?? Battery charge current ?? Buss current on some buss ?? Something else ??
Bob McC
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
Bradburry
Sent: Thursday, November 06, 2014 12:28 AM
Subject: AeroElectric-List: Ammeter going haywire
What could cause the amperage that normally reads about two and a half amps
to suddenly start a smooth and gradual climb over about 35 minutes to 9
amps? Does this mean the battery is going south? Something else?
Bill
www.buildersbooks.com
www.mypilotstore.com
http://www.matronics.com/Navigator?AeroElectric-List
http://forums.matronics.com
Message 5
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| Subject: | Ammeter going haywire |
At 16:05 2014-11-06, you wrote:
Bob,
I am pretty sure that it is reading battery charge current. It is
too low to be alternator output or load I think.
He had been doing some work on the engine and had run the battery
down considerably trying to start it. On the next flight the amps
jumped up to 8 on start then gradually reduced to about 4 by the end
of the flight. The next flight the amps jumped up to 4 on start then
came down to about 2.5 by the end of the flight.
Somewhere in here his mechanic told him he needed a new battery so he
replaced the battery.
The next flight with the new battery the amps jumped up to about 4 on
start, then dropped to about 2 amps for about 10 minutes then started
the gradual climb to 9 amps over the next 40 minutes.
The next flight the amps jumped to about 3 on start then dropped to
about 2 for 10 minutes then slowly climbed to over 4 amps for the
next 40 minutes or so.
This now seems to be the standard.
Any ideas would be welcomed.
Bill
Those readings don't make any sense to me. If it's a battery
ammeter, then the current right after start . . . ESPECIALLY
with a badly depleted battery, would peak at some rather
large number . . . perhaps 20A or more immediately after
the alternator comes on line and tapers to zero over time.
These numbers are too low to be real . . .
First, we need to identify just what the ammeter is
reading. Does it have a zero centered needle with
minus readings to the left and plus readings to the
right? If so, sit in the cockpit with engine off
and turn EVERYTHING in the airplane ON and tell us
what the ammeter reads.
If the ammeter has zero at the left and full scale
at the right, then it's not a battery ammeter. Again,
with the engine not running and EVERYTHING in the
airplane turned ON, what does the ammeter read?
Finally, with the engine running and everything
in the airplane OFF except the alternator, what
does the ammeter read? Then turn everything ON
and take a reading (you need to do this at about
2000 rpm). Finally, if you turn the alternator
OFF while everything else in the airplane is ON,
what does the ammeter read.
In all three series of tests above, take voltmeter
readings at the bus also.
Unitl we first determin exactly what this ammeter
is attempting to tell us -AND- get some numbers
based on behavior, there's not enough data to
craft any sort of diagnosis.
By the way, what engine, alternator and battery
sizes are we talking about?
Bob . . .
Bob . . .
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