Mark,
Does this customer have another charging source besides a generator,
like PV ? That last few percent SOC
into the batteries is very inefficient of course. If they are starting
to charge their batteries only when the inverter cuts
out due to under-voltage cut out, it may be that they have more of a
problem than getting that last 1% into the
bank ? Even if it's charged to anywhere ~near~ 99%, the bank is
running down pretty low (less than 50% SOC anyway)
OK, so the BMK (Magnum's battery monitor), uses 3 criteria which must
all be met before it will give you that
last 1% State Of Charge....
1) The return Amps must go below 2% of the Amp-Hour setting for the
battery bank (settings via the remote).
2) Battery voltage Vs. Time... The battery voltage must remain at a
voltage for a certain amount of time.
The lower the battery voltage, the longer this time it must remain
there. .As long as criteria 1 and 3 are met,
say, if you were in Float (~13.5V per 12V battery), that time is
around 10 minutes.
3) The Amp-Hours IN-to the battery must be within 1% of the A-H that
came OUT.
I am assured (from Magnum) that when it reads 99% SOC it is at ~least~
99% SOC.
As for the bridge fault error, It may or may not be an actual problem.
There has been (as I thought) a software fix in case it
is a nuisance message, that did plague a few of the earlier MS4448AE units.
This all being said, I have included (below) an email I received from
Glen Darby, one of our customer service guys downstairs.
Have a day and 1/2 !
boB Gudgel
Bob,
Your question
(1) Magnum's integrated battery monitor hasn't done a 100% reset for some
> time. It counts up to 99%, no more Is this an equipment glitch? OR:
should we fool the system into repeating the
> bulk charge to try again for the reset?
I would try setting the total amp hrs a little lower and do a reset.
2) The client reports an "Internal Bridge" fault.
This is not normal and if this fault comes back again, the customer
should call our tech
support (425-353-8833) at the time it is in a fault mode so we can
trouble shoot the unit.
The Internal Bridge fault means that the unit senses no ac output
voltage or current when
it senses voltage on the input. It shuts down to protect the fets. This
should not be
caused by the low DCV.
Thank you
(Glen)
boB wrote:
mick abraham wrote:
Greetings, all~
If there is no Magnum employee monitoring the Wrench List, could boB
Gudgel forward this as appropriate?
My client has a "genset plus" system--no recharge other than his
MagnaSine
4448AE driven by a generator. Batteries are a single string of Deka
8L-16's, a
few months old. We're running the charger defaults: 48 amp maximum
charge
rate, 2 hour absorption, and flooded setpoints.
(1) Magnum's integrated battery monitor hasn't done a 100% reset for
some
time. It counts up to 99%, no more, according to the report from my
customer.
I asked the customer to run the generator for longer than his normal
pattern,
in order to force the meter to reset (and also to increase battery
SOC). The
"AH I/O" counter ran up to about 78 amp hours above zero and the
inverter/charger went into float for over an hour...but still we got
no reset
on the counters.
Is this an equipment glitch? OR: should we fool the system into
repeating the
bulk charge to try again for the reset?
(2) The client reports an "Internal Bridge" fault. This has happened
multiple
times because the customer has become adept at resetting the unit per
page 36
of the manual. The manual says nothing about "internal bridge", but
repeated
shutdowns seem non-normal to me. I do notice something in the manual
about the
"FET Bridge" so maybe that's where the trouble is.
The customer has been pounding their batteries by driving the
inverter until
it shuts down due to low battery voltage. Could that trigger the
"Internal
Bridge" fault? It certainly triggers my cringe reflex...
If we can get the percentage meter back on track, that might help
reduce the
customer's "drive until it dies" behavior. Here's hoping...
Thankx,
Mick Abraham, Proprietor
www.abrahamsolar.com
Voice: 970-731-4675
No problem, Mark. Your info is being forwarded to the Magnum
Engineering department now and I will follow up
on this when I get in tomorrow morning. The 99% (BMK) issue is
familiar but I can't remember off hand exactly what the
solution is. I believe the internal bridge fault (inverter), was on
earlier units and has a software fix as I remember.
You should get more info hopefully tomorrow.
Thanks,
boB
.
_______________________________________________
List sponsored by Home Power magazine
List Address: RE-wrenches@lists.re-wrenches.org
Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
