I installed a Link 20 on my sailboat about four seasons ago. I used
the Xantrex wiring cable and followed the instructions correctly.

I have two Optima spiral cell batteries. About 75 amp hours each

The problem I started to have was the amp hour page would not reset to
zero or close to it after extensive charging. At anchor I would show
a depleteion of say 40 amps. The charging would show that I had
replaced say 20 amp and the unit would show I was down to say 20 amps
but at that point the batteries were not accepting any more charge. So
in reality my batteries were fully recharged but the Link said I was
down 20 amps. If left it this way the battery condition lights at the
top would start to show the batteries we getting low. If I reset the
amp hours the green lighst would come back to full charge.

For two years I talked Xantrex techs and got little satisfaction.
Check the wiring, reset the functions, etc. Whatever they said to do
did not correct the situaution.

Then last week I discovered the unit was dead. No LED read outs except
for the green battery boxes across the top which tells me there was
power to the unit so it was not a fuse problem

Xantrex was of no assistqance and they told me to call Tekris a
company that repairs Xantrex products. Tekris advised that they really
don't work on LInk 20's but if I would like to send it in they would
tell perhaps what the cause or problem was. So I am now waiting for
their input.

I have had two boaters at our YC that had similar problems. So my
question is are these units prone to failure? I like the idea of
having a battery monitor but at $400 a pop I don't want to go thru the
same problems.

What has been your experience with the Link 20?

Thanks, Jerry

Gerald Atkin wrote in
:

What has been your experience with the Link 20?



I would try to replace the cable between the Link20 and the battery box,
first. I had one that was "flaky" and there was a leak caused by water
intrusion into the cable. There was a leak between the shunt wires and the
power wires fooling the link into thinking there was current in the shunt
when there wasn't.

As we are replacing the cable, let's make sure we shine up the shunt
connections which get pretty corroded if the bilge is wet. The voltage
output of the shunt is MILLIVOLTS when there are a lot of amps flowing
through the shunt. Millivolts can also be created by the tiniest little
bi-metal battery across a tiny bit of connection corrosion. The millivolt
difference between one side of the shunt small screw wires and the other is
all there is for the Link20 to measure. Imagine adding a corrosion battery
in series with the 50mv from the heavily loaded shunt. The reading that
results is really crap!

Please use RING TERMINALS on all the connections to the shunt, new fuses
and fuse holders (radio shack's work great), and never just wrap wires
around screws to get it hooked up. After you crimp the terminal to the
small guage wire up to the link (really small wire works fine), seal up the
crimp with a tiny bit of sealer to keep the crimp from corroding.

Leave plenty of wire so we can go back in a couple of years, cut off these
terminals and put new terminals on without stretching the wires because you
tried to get too cutesy....

The LED display blanks when the reading makes no sense to the Link. That's
normal. I think we have some stray millivolts being fed to the current
sensing of the link. New wires and terminals and cleaning the shunt's
screws will cure it. MAKE SURE YOU DO NOT SCRAPE AWAY ANY OF THE METAL
FROM THE SHUNT! We trim shunts with a file to make them calbrate. You'll
see file marks. More filing will make current readings too high...not
good.

On Mon, 15 Sep 2008 01:37:29 +0000, Larry wrote:

Snip
The LED display blanks when the reading makes no sense to the Link. That's
normal. I think we have some stray millivolts being fed to the current
sensing of the link. New wires and terminals and cleaning the shunt's
screws will cure it. MAKE SURE YOU DO NOT SCRAPE AWAY ANY OF THE METAL
FROM THE SHUNT! We trim shunts with a file to make them calbrate. You'll
see file marks. More filing will make current readings too high...not
good.


I think that you are "a bit over the top" here Larry G
The connection screws are normally tapped into brass blocks, there is
no problem with cleaning and polishing and if badly corroded filing
this screw area. I totally agree that filing the actual shunt material
between the two blocks is a NO NO. I am sure that is what you meant
but hope this makes it a little clearer to those with less knowledge.

Richard

On Sun, 14 Sep 2008 13:17:58 -0400, Gerald Atkin
wrote:

So my
question is are these units prone to failure?

In a word, yes. They are very nice when working properly but glitchy
and unreliable in my experience.

All you really need is a decent digital voltmeter. Under light to
moderate load the batteries need to be recharged when they drop below
11.8 volts. That's about 60% of full charge. Anything lower will
begin to damage the batteries.

Richard Edwards wrote in
news
On Mon, 15 Sep 2008 01:37:29 +0000, Larry wrote:

Snip
The LED display blanks when the reading makes no sense to the Link.
That's normal. I think we have some stray millivolts being fed to the
current sensing of the link. New wires and terminals and cleaning the
shunt's screws will cure it. MAKE SURE YOU DO NOT SCRAPE AWAY ANY OF
THE METAL FROM THE SHUNT! We trim shunts with a file to make them
calbrate. You'll see file marks. More filing will make current
readings too high...not good.


I think that you are "a bit over the top" here Larry G
The connection screws are normally tapped into brass blocks, there is
no problem with cleaning and polishing and if badly corroded filing
this screw area. I totally agree that filing the actual shunt material
between the two blocks is a NO NO. I am sure that is what you meant
but hope this makes it a little clearer to those with less knowledge.

Richard


I just don't want him yacht polishing up the shunt bars to make it pretty.
That will screw up the calibration. Cleaning around the screws is fine.
Those blocks are way too thick to change the shunt calibration, which on a
Link 20 isn't really that important as the batteries are never going to be
anywhere near the AH rating stamped on the side and programmed into the
Link anyways....

I've got a L20 which I bought from USA a few years ago but only
installed in the last few months and it seemed to work really well. A
couple of weeks ago it light up like a Christmas tree and apart from
the voltage reading, all the other functions were complete garbage.
Discovered that during its CPU attack it had set itself to LOC, so
once I had unlocked it it started to behave a bit better. Any amp
reading is still odd - indicates charging on the "t" function when it
is discharging. Have done the basics of disconnecting it and leaving
it for 24 hours and resetting. Xantrax FAQ also suggests grounding
the shunt sense terminals, which I have yet to do.

There are voltmeters that can do essentially the same job - www.smartguage.co.uk
- but I like the ammeter function of the L20 to see what is using the
power. I guess a Smartguage and digital ammeter to use the L20 shunt
would do the job and probably be more reliable.

I've got a L20 and after a few months installed, it had a CPU storm.
Volts now works OK but any of the amps functions are a shambles.
Tried resetting, have yet to ground sense circuitry which will be next
step. Shame really as the ammeter was really useful in bowling out
what was using the amps.

Gerald,
1) Not resetting to zero ... sounds to me like either the charger's
ground lead is connected direct to the batteries bypassing the shunt,
or a ground lead is running from the starter battery ground to the
starter or engine block. The ground legs of your battery must have
absolutly nothing connected to them except for the shunt. No
exceptions. It's hard to not have an exception. Heavy wires from
chargers, inverters, etc. may be inconvient to route to the shunt, and
misc. devices that are connected direct to the battery as part of the
boats wiring harness, like your bilge pump, need to have their ground
wire rerouted to the shunt.

2) Dead except for green bars ... I had the same problem last month,
disconnecting and reconnecting the link 20 power lead at the battery
cleared the problem for me.

Dan (b393capt)

Gerald,
1) Not resetting to zero ... sounds to me like either the charger's
ground lead is connected direct to the batteries bypassing the shunt,
or a ground lead is running from the starter battery ground to the
starter or engine block. The ground legs of your battery must have
absolutly nothing connected to them except for the shunt. No
exceptions. It's hard to not have an exception. Heavy wires from
chargers, inverters, etc. may be inconvient to route to the shunt, and
misc. devices that are connected direct to the battery as part of the
boats wiring harness, like your bilge pump, need to have their ground
wire rerouted to the shunt.

2) Dead except for green bars ... I had the same problem last month,
disconnecting and reconnecting the link 20 power lead at the battery
cleared the problem for me.

Dan (b393capt)

On Nov 30, 11:25*pm, b393capt wrote:
Gerald,
1) Not resetting to zero ... sounds to me like either the charger's
ground lead is connected direct to the batteries bypassing the shunt,
or a ground lead is running from the starter battery ground to the
starter or engine block. The ground legs of your battery must have
absolutly nothing connected to them except for the shunt. No
exceptions. It's hard to not have an exception. Heavy wires from
chargers, inverters, etc. may be inconvient to route to the shunt, and
misc. devices that are connected direct to the battery as part of the
boats wiring harness, like your bilge pump, need to have their ground
wire rerouted to the shunt.

2) Dead except for green bars ... I had the same problem last month,
disconnecting and reconnecting the link 20 power lead at the battery
cleared the problem for me.

Dan (b393capt)

If that does not work, also disconnected the Link 20 battery voltage
sense leads at the same time.