Xantrex Tru charge 2... and Dometic cold machine

[Mark Maulden]

So, a year ago, when I bought this boat, I replaced the batt charger with a Xantrex Tru charge2 60a charger. Been working great, (although I had to replace it once at inital install). Anyway, it has charged all three banks well in the last yr. Within the last several weeks, I installed a Dometic cold machine refer unit. First one had no freon charge. Had to rip it out and take it back to WM. Second one works fine. Until I started monitoring batt votages. Which ever bank is selected by the batt switch does not get charged when the refer unit runs. I turn refer off and cycle the charger circuit breaker. Everything charges up. Turn on the refer and the selected bank goes to 12v. Anyone have issues with either of these two units in like circumstances? I'm so pissed. Things you buy today are crap (putting it rather nicely) and it isn't just Chinese. This is obviously an EMI problem and I could probably solve it as I am an EMI engineer for a rather large aerospace company. But, why should I have to do that? Besides, at work, I have access to millions dollars of test equip. At home, all I have is a VOM.. Very frustrating..

 

[Stu Jackson]

Mark, sorry to hear about your recurring issues with initial installations. You sound like a DIY kinda guy. Have you considered chargers other than Xantrex, like the Sterling or NEWER ProMariner chargers? Reason I ask is that Maine Sail is positive about them and Xantrex has had tons of bad press on their equipment in the past year (as you seem to have found out). Good luck.

 

[Mark Maulden]

Tnx Stu. I haven't heard about the "bad press" on Xantrex. Always thought they were pretty reputable. And ya, I pretty much do everything on the boat(or ??) that I can. Gear trains? Well maybe not. However, 45 yrs ago, I rebuilt my first engine learning from a book and have rebuilt numerous since so who knows.... With this problem, you/I have to ask.... is it the refer's fault for emitting "to much"? Or is it the batt charger fault for being "to susceptible"? I know it's not an issue of wires being run together as I intentionally ran the charger's batt wires separately with at least 8" separation from everything else and they're only about 7' long. If it was coupling into the AC input, then I would expect the same indications for all batt banks simultaneousy. In the aerospace world, I put systems in a lab and it tells me (most) everything. Here, it's kind of a crap shoot. Do I replace the refer (again) or do I replace the charger (again)???? I don't have a lab at home. So, if Xantex has a bad rap, maybe that's the way to go....Perhaps I'll find a portable AM radio and see what it sounds like when I turn the refer on. It'll tell me something about broadband noise being emitted. Gotta find a radio though....These days, power supplies for electronics are switching power supplies and not "well" filtered. Usually, 10Khz - 100Khz (+ harmonics).

 

[Stu Jackson]

It sounds more like a charger power issue than anything else. You might want to purchase a DC clamp ammeter, but if your fridge is running at around or a tad less than 5 amps, that sounds just right. How old and what condition are your batteries?

http://forums.catalina.sailboatowners.com/showthread.php?t=136765

 

[Sumner]

It sounds more like a charger power issue than anything else. You might want to purchase a DC clamp ammeter, but if your fridge is running at around or a tad less than 5 amps, that sounds just right. How old and what condition are your batteries?

http://forums.catalina.sailboatowners.com/showthread.php?t=136765

I agree and would also check the amperage on the frig. The VOM connected in series with the amp setting should work. Most, even the cheap ones, have an 'up to' 10 amp setting.

I made a frig for the endeavour with the Dometic 84 plus unit and it seems like the 5 amps on startup is about right. I had charger problems using a Schumaker portable charger but then connected the shore power cord, we are up on stands, and used the boat's Heart charger/inverter and it has run with no problems at all.

If the frig is pulling less than 6-7 amps max then I'd be suspect of the charger. I'd also take it out of the circuit and see what battery voltage is before and during frig operation is. If it is high/mid 12's without the frig I'd look for low 12's with it running and then hooking the charger in should show an increase to high 12's and around 13.0 once it gets to float. At least that is what I'm seeing with our monitor.

We are really, really impressed with the Dometic unit. We have the largest evaporator freezer for it and it is hot here, low 90's, and the frig is hardly ever on and the freezer and frig are full. It is larger than the portable 63 qt. compressor style frig we use on the Mac and also here before the new one was installed and uses way less elect., but it also has lots more insulation.

Good luck,

Sum

[FONT=Arial, sans-serif]============================[/FONT]

Our Endeavour 37

Our MacGregor 26-S Pages

Our Trips to Utah, Idaho, Canada, Florida

Mac-Venture Links

 

[Mark Maulden]

The batts are a year old. They are Dyno's GC2b. According to the panel meter, it pulls about 10a on start and settles on 5a. Have not observed anything abnormal there. About what a couple light bulbs draw.

 

[Stu Jackson]

Mar, that sounds just right, so it ain't your fridge. One down...

 

[Maine Sail]

The batts are a year old. They are Dyno's GC2b. According to the panel meter, it pulls about 10a on start and settles on 5a. Have not observed anything abnormal there. About what a couple light bulbs draw.

Mark,

Something is not right.

Where are you "sensing" the voltage you are reading?

Where does the charger connect to? The batteries, the switch, somewhere else?

Are you using the temp sensor?

Are you using multiple outlets on the charger or just one?

Do you have a battery isolator?

Where does the fridge compressor connect to?

If your batteries are fully "charged", and healthy, no bank of 2 GC2 golf carts, at 235Ah's, should dip to 12V running a 5A load until they have been quite severely discharged. Heck our six year old Wal*Mart bank will easily hold 12.65+V running a 6+A load for quite a while.....

Those Dyno batteries should be able to support at least 12.5V + while running that 5A load, if they were full or close to it when the load kicked on, and in good healthy shape..

I just came in from my barn where I ran a 5.4A load for a tad over 30 minutes on a single fully charged group 27 Dual Purpose West Marine battery. The battery is dated July 2007 and has been in deep cycle use on a customers boat since 2007. It is in my shop for equalization and conditioning. It was still above 12.69V after 30 minutes at 5.4A.... This battery is less than half the size of your bank, 5 years old, pretty abused, and still supports a 5.4A load for 30 minutes without dipping below 12.69V....

We need more details to help you out. The only way your batts are dipping to 12.0V with a 5A load are;

*Not as charged as you think
*Badly sulfated
*Your meter is giving erroneous readings
*You are sensing voltage in the wrong spot and/or have wiring or voltage drop issues.



P.S. Please do not connect a DVM in series to your fridge load to read current. You will blow the internal fuse on the motors inrush..

 

[Mark Maulden]

Update: woke up early and had a few hrs to go to the boat. Loaded up my good VOM and clamp on ammmeter and had a plan. Got to the boat and fired up the refer etc and everything played well together. So, OK, I ran every system on the boat and let refer cycle and manually cycled it and I could not get the charger to fault. I'm still going to take some voltage/current measurements with the charger off at some time. It's now a little lower on the list. Answers to Maine's questions follow:

Voltage is read on the breaker panel at the batt switch posts. Through a switch so one meter reads two banks. Charger has three isolated outputs and connects directly to each battery directly. .No temp sensor used. Xantrex set for the middle setting. No batt isolator. The fridge is connected to a breaker on the panel which is supplied via the batt switch (awg 10 for ~10' . This system is as delivered from S2 and is a "dumb" system. As in I have to manage the load source and the charge destination manually. And, I don't mind that for now. The only thing I don't like is S2 used #4 wire between the batts and the switch/panel gnd. Not really big enough and I cannot get the wires out of the bundle under the cabin sole. so, I'll have find a route for new wires which will be about 12' long which means 24' long as for wire sizing. I did install a separate starter battery/switch and other than the panel feeders, all wiring is new and 2/0 size.

 

[Mark Maulden]

Forgot one thing.. The only thing I can think of that may have caused this problem initially is perhaps a tight compressor being new and the controller may have had some strange waveshapes that the charger didn't like. Although batts make great capacitors...I think the refer takes 12v and converts to ac. Not sure though. And... there's no mention of being FCC compliant that I can find in the manual.......