Today's Message Index:
----------------------
1. 10:35 AM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
2. 11:27 AM - Re: Re: voltage monitor (Robert L. Nuckolls, III)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: voltage monitor |
New post
Posted: Sun Oct 04, 2020 4:51 pm Post subject: voltage monitor
<http://forums.matronics.com/posting.php?mode=quote&p=498671&sid=6781a385e9dbba117a35c9138433dbef>
Reply with quote
----------
From: Technical Manual for Model No. LR3D-14 and LR3D-28 Linear
RegulatorWith Over-Voltage Protection, Low-Voltage Sensing, And
Field-Adjustable Charging Voltage
"The LV warning light will begin to flash when the voltage sensed at
terminal 3 drops to approximately 12.7V and below"
Disregard if this is not relevant to this discussion.
It is very relevant. Thank you.
This is news to me but I've not been directly
involved or plugged in to B&C design decisions
for some years
With that in mind, and given the number and
variety of programs I've worked it seemed
prudent to verify the hip-pocket archives.
Dug out my AEC9005 drawings and the setpoint
was 13.0 volts. All the data I have on early
LR3 series regulators suggest that 12.7
has been the setpoint from day one.
Just for grins, I plotted Time-to-12.7v
for four batteries. An AeroVolts, an
exemplar EarthX, a Miady 16AH device
and just for the heck of it, a fresh
Enersy 16AH battery. Plots attached.
I've also included a test for a A123,
26650 cell where I deduce that a 4x4
array of these cells in a 14v system
battery would fall below 13.5 volts
in about 30 seconds.
I suggest these plots show that a 13.5
volt lo volts warning threshold would
be suited to all chemistries. Note that
the SVLA falls like a rock to well under
12.7 when it looses alternator support . . .
well, it IS a 12v battery while LiFePO4
devices are generally considered to be
13.2 volt batteries (although AeroVolts
labels theirs as a 12V while the plots
show that it has the highest alternator-
out voltage of the lot).
Hence, I stand better informed and
agree that the legacy LR3 configuration
is unsuitable for lithium battery management
without (easy to do) modification as
is our AEC9005 LV Warning Module.
Sorry for ignoring you the past day or
so. Been wrestling with some issues
in a car I've got sold . . . along
with a recalcitrant wifi router.
Ever see the look on the fact of a couple
teenagers when you tell them, "the
wifi is down"?
Bob . . .
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: voltage monitor |
At 05:52 AM 10/5/2020, you wrote:
>
>the link charlie posted shows a graph i am used to seeing with the
>earthx. i take this graph to mean i will give up 3ah of battery by
>using 13.0 as a setpoint vs. 13.5 volts. i have no second
>alternator so it is important to me to know asap when i have only
>battery power to keep the engine running.
13.5 is cool . . .
Bob . . .
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|