Xantrex Freedom 2500 and Link 2000

[Strygaldwir]

Just "mostly" completed installation of a Xantex Freedom 2500 and Link 2000 monitor in a Privilege 37 catamaran. The installation was "relatively" straight forward. I installed the inverter in the starboard engine compartment. There is a shelf that looks like it was designed for it. As a matter of fact I know it was designed for it. There was a junction box installed right next to the shelf with a lable for an inverter on the box. The fact that the AC source and AC lines to the distribution panel were already installed made installation somewhat easier. I did have to install a battery/inverter switch to cut the supply to/from the battery banks. I also installed a 200 amp ANL type fuse on the positive side leading to the main battery bank. I used 1/0 cable to the battery banks. It is about a 3' run (1' for the negative line 1.5' for the positive line). The most challenging part was routing the lines in a semi-neat fashion. I still need to install the temperature sensing switch on the battery, but that is 4 minutes tops.

The Link 2000 was a little bit more of a challenge. There are 9 wires for various functions that have to be connected. Basically there is a 12volt supply line pair. 2 lines for voltage sensing against 2 battery banks. 1 line for a backlight in the link 2000. 4 lines for amperage sensing, 2 for each battery. Asside from the tedium of connecting ring terminals for all the small lines, more interesting is tapping the appropriate locations. The supply lines I taped from after my main battery switch. I put it on the common pole. As long as I have either battery bank on, power is available to the monitor. If I shut down the power, there is no monitoring function. The battery voltage lines were tapped from the post on ANL battery fuses for each bank. This was straight forward. The challenging part has been the AMP sense lines. There is one shunt that is included with the Link 2000. Because I am installing in a catamaran and I have the main bank in one hull (starboard) and the starting battery in another hull (port), if I use one shunt, I am only able to measure amperage use of the starting battery after the starter and alternator. Not exactly what I want! Especially given that that is all the load on that bank. Therefore, even though that is how I have it currently wired, I will try to get another shunt and put that right off the starting battery. This will allow me to measure total amperage draw on the port battery.

Once I get that cleaned up, I'll really be able to say it is complete. Only took about 7 hours for the installation, but that did include a trip to the electrical supply house for some supplies.



Keith

[Rick]

Do not use separate shunts to use the Link 2000 for monitoring two separate sources or loads. The dual shunt provided serves two purposes: It gives you the ability to easily (and properly) connect the instrumentation black (common) wire without having to stack a low current small wire on top of a high current carrying conductor lug. It prevents an installation from having different negative potentials between the two sources or loads. Using separate shunts will allow physically distanced negative connections which ALWAYS results in different negative potentials relative to each other when large currents flow.

If you cannot rationalize running long negative cable lengths to a dual shunt then do not use the Link 2000, use two separate battery monitors. The accuracy of being able to measure +/- 100mA on one channel while measuring +/-500 A on the other channel will be affected by the voltage on the black (negative) wire to the link 2000 relative to the Kelvin connections made to the two small screws on the shunts. If you were to separate the shunts you would not be able to guarantee a sufficiently low difference in potential.

I don't know why you feel the need to use a full-on battery monitor capable of measuring accumulated energy for a starting battery. Normally a voltage measurement is sufficient (which is why the Link 1000 measures one channel of +/- energy and another channel of voltage only for a separate start battery). The E-meter does this as well.

Don't waste the design accuracy of voltage measurement by connecting the voltage input leads to any other connection other than directly to the battery positive (somewhere physically near or on the post). Do not connect the power to the Link 2000 to a switch which can cause loss of instanteous data should the switch be opened. Instead follow the installation instructions and connect the red wire via a 2A fuse to an uninterruptable source of power (8-40V). If you feel the need to disable this lead for long periods of idle time (months or more) then merely remove the fuse. Setup data and cardinal measurement data will not be lost.

Regards,
Rick

[Strygaldwir]

Rick;

Thanks for the input. I had not noticed that you responded until now.

If I were to use two shunts what could I expect for an error factor? What I intend, is to test with both the single shunt and dual shunt. Often times I find that although an installation may not be optimal, it may be sufficient for a purpose. If the error is in mili-amps, it is insignificant, for my purposes. If there is a error factor that is measurable in amps, I may just forgo amp readings on the starting side. The effort and introduction of significant runs of 4/0 cable merely to measure amperage utilization has little utility and introduces additional point of failure.

I will keep the Link 2000. Got it at a great price. It is definately not worth the effort and expense to trade it out for a Link 1000.

I felt it necessary to measure the amperage draw because it help me identify points of failure. Once I have established baseline measurements, I can detect varriance from that baseline. It has been my experience that if I am able to see the draw on my starter that I have an indication of potiential problems. This helps me to do things like determine appropriate maintenance cycles, and determine when I should go looking for any issues. i.e. corosion, loose connectors, worn brushes, commutators... etc.

I debated mounting the voltage sensors to the switch vs. fuse terminal. I'll take your recommendation and shift this to the fuse terminal. I won't connected to the battery terminal. I only connect primary connection cables to the batteries. Two inches with 4/0 cable can't introduce enough systemic voltage drop to be significant for my purposes.

I have wired the primary voltage source and voltage leads through 2 amp fuses as suggested. I wish I could find auto style fuses in 2 amp configurations. I had to use the glass type. Oh well.

I certainly wish the instructions that were provided with the Link were more clear. I just received two diagrams that did little in helping me understand the installation trade-offs. Especially since my configuration is entirely different than either of the two diagrams.

[Alan Wheeler]

Personally I wouldn't go trying to make the situation of measuring too complex. Somethings you just don't need to know. Especially because as a starting system fails, the faults will show up in other ways. You may (or as you read on you will see you may not) read a figure drawn, but it isn't going to tell you just exactly what is failing. The numbers may show that there is something different to when you last started the engine.
Plus two other problems will come up if you try "seeing" what current is being drawn on a start cycle. First off, the start cycle is relatively short. This will make it rather difficult to get a meaningful reading. Secondly, the reading is not going to be steady at all. As the engine is turned, it goes through stages of load change. The changes are dramatic, from the initial start of the starter, which is firstly trying to get momentum going. This can take hundreds of amps to do so. Then it is throwing the gear out to engage, which draws a varying current through its travel, then the motor changes resistance as it heats up and mate they heat up. Then the engine itself, being dead cold will have a high load that decreases quickly as momentum builds and oil travels and so on. The load will climb as a cylinder compresses and the load will decrease in between that cyclinder decompressing and the next cyclinder about to. So you will struggle to gain a reading as the numbers will be all over the place.
I would keep to the installation instructions.

[Strygaldwir]

The problem is still one battery bank is 15 feet from the other. The only way to install the shunt as described in the manual is to run 30 feet of 4/0 cable from one hull to the other, then 30 feet of 4/0 (larger than 70mm2) cable back. I won't do that.

I was trying to make it simple. I bought another shunt for $25. I was going to put the shunt that came with the Link near the house bank and wire it as per the diagram. I was going to take the other shunt and put it near the battery bank in the other hull. My contention is if there are errors, I don't really care. I am more interested in variance from a base line. I know it is not a saftey issue to have two shunts. I can imagine introducing errors in the amperage readings, but I don't think they are large.

In anycase, it is my intent connect it both ways with temporary cable. If I don't get significant variance between the two test. I'll install the two shunts. If I do, I'll just use the one shunt and have no reading for the second battery bank.

I'll be back in florida in a couple of days. I'll provide the results of the test on this thread then.

Thanks,

Keith

[Strygaldwir]

Oh yes, Given the choice of having instrumentation and not having instrumentation. I always like instruments.

Yanmar says I only need an RPM meter and idiot lights and buzzer for my engines. I disagree with this. I put in oil pressure and water temperature. The presence of a oil pressure gauge saved me about $25k on an engine once. If I see something changing in a gauge, I immediately ask my self why? I would investigate it. Probably cause me to check the readily accessable failure points. If I found no issues, in this case I'd pull the starter, maybe check/replace brushes, maybe replace the bearings. If I still had problems, probably would check compression in the cylinders... It might be nothing, but using this approach has caused me never to be stranded in cars that have been over 50 years old.

Actually the link will tell you how many amps you pulled from a battery. I imagine you could get an average/mean/min/max expenditure of amps if I wanted to. But time and experience will tell if it is of any value.

Cheers,

Keith

[Alan Wheeler]

I agree 100% with an Oil pressure gauge and a water temp gauge. Infact, adding a water flow gauge to the salt water side of the cooling can be even more benificial. It can sound an alarm and draw your attention to a problem like a plastic back stuck over the intake, of which you can avert any damage to cold water pump impellors etc.
But what I was trying to say before, was that the reading is going to be so vast and fast changing, that they won't give you any reliable info to whether the starting system is good or bad or what ever.