[Larry & Diane]

I just submitetd a much longer detailed note, but it appears lost in the ether.

The short version. It’s possible to rewire your single battery bank so that’s it two battery banks, each dedicated to an inverter/charger, That takes care of the charging issue and should prolong the life of your chargers. But it’s beneficial to have one battery bank for inverter operations given it’s impossible for each inverter’s load to be identical. With unequal loads one bank will draw down before the other. Another problem with one bank is which would trigger the generator auto start circuit?

The solution having a common battery bank now that you’ve split them in two is to install a solenoid and appropriate circuit protection between the two battery banks. The solenoid would be trigger by the absense of AC input power to the inverters. The only challenge might be finding a continuous use solenoid that was large enough for the load. I could find one rated at 200A at 12V, which would be sufficient for two 2500 watt inverters. 4KW inverters should have a larger solenoid. For 24V banks the only downfall to this is that you 12V equalizer would draw off only one bank.

[Archived]

There has been a lot said about this phenomenon at the end of the charge cycle of using twin Trace SW4024 inverters, and most is true, however, anyone with this inverter setup needs to remember the “big picture”:

This is only allowed to happen for a short time period that one inverter is in Absorption charge while the other is in Float. The absorption time limit is only 3 hours. This is really not a problem, and has been installed in coaches that get battery life of up to 10years, depending on number of cycles. As for the “fighting” between the inverters, is not detrimental in reality, as this series of inverters have the highest reliability rate of ANY INVERTER I have seen on the market now or in the past. They are installed on literally a thousand or more coaches (this number made up mostly between the huge fleets of Vantare’s and Marathons, plus Angola’s and Parliament’s and the last version of Country Coach and Legendary).

I just want to reassure owners of these inverters not to “sweat it” when it comes to the exact workings of their inverters. As long as they have the battery temperature sensor feedback, they will not damage your AGM batteries.

Thanks,

Ben Cummings

Parliament Motor Coach

ben@parliamentcoach.com

888-571-5755, ext 230

813-830-8619 (Cell)

[Susan]

I appologize if my postings implied there was a fault with the Trace inverters themselves. I feel quite the opposite. I have an SW 4024 that has been used and abused for 10 years. it tolerated the unstable power grid in the Bahamas for 5 years often seeing 130-140 volts then down to 80-90 volts. The frequency of power in the Bahamas goes up and down between 58 and 62 hertz. all the time. Throw in high humidity and salt air, it has had a tough life.

It now lives in the mountains of NC, has been hit with lightning twice and is still going strong and giving great service.

My concern is not with the inverters themselves, but how they interact on my coach. The way they function for me creates a situation where it is very easy to exceed a 50 amp load on one leg thus tripping the pedestal breaker. A slight alteration the charging settings has reduced that concern and I now feel I can leave the coach for a day and not worry.

I agree with Jon, the issue could be corrected by two battery banks but as he points out, that is not needed.

I also agree with Ben, they are great units. As to the “big picture” comment, mine was why am I tripping pedestal breakers?

Again, sorry if anyone took my posts as an inverter bashing. Just trying to pass on information as I learn.

[Archived]

I picked up a 2002 H3-45 Vantare earlier this year and I have noticed the exact same situation you describe with the negative amperage on inverter 1. As I started to dive into what was causing the issue I came to the conclusion it was the charger as I could disable the charger on inverter 1 and the issue would seem to go away. Then I came across a Trace tech article that talks about two inverters attached to the same bank of batteries can start to fight against each other and acutally cause the bank to never get to fully charged. I could see this happening if I looked at the battery voltage as the voltage would swing +/- .5 to 1 volt during charging as one inverter would charge and the other would then show a discharge. When I disabled the charger on inverter 1 it resolved that issue as well. I finally resorted to running the system with the bypass switches both in bypass so I would not cause an issue at the pedestal until I figured this out.

I found a bad battery temp sensor (BTS) which was reading 05 on panel 21 (battery temp) and I thought it was the problem, so I replaced it, and it helped some in the wild swings, however it did not solve the discharge issue. During all this, the 220v plug at the pedestal was extremely hot if I kept the bypass switch in the inverter state, if I flipped them to bypass the 220v plug ran considerable cooler. Which tells me that one of the legs is drawing way more power than the other. I was just about to track down my AC clamp meter to measure the legs at the input plug to verify and I ran across this article. So I will now try setting the charge amperage on the inverters such that inverter 2 charges and inverter 1 does not. I have the same firmware in my 4024’s, so I believe we have the same exact issue and this should address my issue such that I can set the bypass switches back to inverter. To think it has probably been running this way since the coach was sold.

As part of this effort I also determined that in my H3-45, there are the two battery banks, one of each rear axle. The batteries on the curb side run considerablly hotter than the batteries on the street side. Not sure which of them is the 24 volt bank vs. the 12 volt bank, but they both get charged by the inverters. I am thinking the curb side (the hotter ones) must be the 24 volt as they inverters charge them directly. The 12 volt bank (based on electrical drawings) gets charged through the 100-AMP equalizer and therefore would charge at a lesser rate I believe, and therefore would not get as hot as the 24 volt batteries. The reason I bring this up is because both of the BTS are on the street side (cooler batteries). I have since moved them to the curb side so they are on the hottest batteries vs. the coolest. Not sure if that is a good move or not, so any of those with more knowledge on this please chime in.

[Archived]

Michael,

You are now the fourth Vantare owner with the same inverter
symptoms and issues and the second one commenting on the battery temp sensors.
(BTS).

It has me wondering if the temp sensors are a significant
factor. On my coach, the BTS for inverter #1 is glued to the 24-volt battery
bank and the BTS for inverter #2 is glued to the 12-volt battery bank. The
wiring diagram shows this as well.

Since both chargers are charging only the 24-volt battery
bank and the 12-volt bank is charged indirectly, is it possible the temp
variations are confusing the inverters? It might be worth unplugging the BTS
going to the 12-volt battery bank as a test.

Anyone have any thoughts? Maybe Ben Cummings could comment
on this.

Paul

[michael]

Here’s a caution Vanner has on charging a 12V bank and splitting 12V off a 24V bank.

In certain applications, such as private coach or alternate energy applications, it may be desirable to have additional 12 volt “House Batteries” to operate heavy 12 volt (inverter) loads. Use the Equalizer to charge the additional batteries.

Connect the Equalizer 12V terminal to the additional batteries only. Do not connect the Equalizer 12V terminal to both battery banks as this would make Battery A larger than Battery B. Damage to Battery B may occur during charging due to overcharging, if the equalizer cannot keep up with the chargingsystem.

There illustration may help: http://www.vanner.com/manuals/EQUALIZER-60-SERIES.pdf go to page 8.

[Michael]

Paul,

Not sure where I read it (I believe it was in a Trace document), but it said that when you have two inverters and split battery bank attached in parallel, that both BTS should be on one battery bank not split. I believe the reason why this is the case is if one bank is cooler than the other, the firmware will change the charge ratio based on battery temp and they will surely fight at that point.

However, the note did not say what bank to put it on, such as the cooler or hotter set.

[Michael]

Gil,

My schematics are at the coach. I have two 100-AMP equalizers, it looks like I need to check to make sure the equalizer 12v side is not hooked to both battery banks.

I have a total of eight 8D batteries, four on each side of the coach. So 4 of them make up the 24V battery bank and the other the 12V battery bank. Based on the drawings I reviewed in the Vantare schematics, It appears that the 12V battery bank can also be consumed by the Inverters as they are tied to the inverters through the eqaulizer.

I will check the schematics on how the 12v side of the equalizer is setup when I go to the shop tomorrow. But I would suspec that Vantare knew what they where doing and setup them up this way. I believe the reason the batteries are warmer on one side vs the other is because the inverter is charging them and the equalizer is then transfering power to keep the voltage within spec.

[Archived]

Michael,

I would love to see a Vantare schematic. Some things just don’t seem to make sense. I’m not sure an equalizer was ever designed to convert a single 12V bank to 24V for connection to support a 24V charger/inverter. The equalizer’s primary role is to voltage balance 2 12V batteies; where’s the other battery? I can’t understand the value of even configuring the bank for 12V when it has an equalizer, 24V inverter/charger, and 24V alternator.

If I ever get a chance to see the schematic my light bulb will probably light, but right now it is not.

[michael]

Gil,

I have the full schematics for my coach from Vantare, and am I glad I do. I just went through the entertainment system (salon, stateroom, and storage) and converted everything to HDMI and new LCD TV’s. The amount of audio/video cables and composite amps was crazy. I also moved the satellite controller and receiver to the front while I was at it and ran 5 runs of CAT5e wire from front to back in the upper wire conduit so I could do HDMI over CAT5e to the bedroom, plus have Ethernet to the smart TV and the Laser Printer. The schematics helped me understand all that silly wiring, but it took a lot of work to read all that silly small print even with the bifocals 🙂

I can take a snapshot of that section of the schematic and email it if you would like so you can see how the two battery banks where configured by vantare with the two vanner equailizers. My coach chassis is a 1999 but was not sold to an indivdual till 2002 (so its titled as a 2002), at which time Vantare re-retrofitted some of the interior such as the entertainment and cockpit area with the 2002 layout.

[AL]

Michael, sure send me s copy.

It sounds like Vantare installed overhead conduit. I don’t know why all converters don’t do the same.

[Larry & Diane]

Gil

sent you private email with schematics. I have looked at the schematics and all 8 batteries make up the 24 Volt DC Circuit while only four of the batteries make up the 12 volt circuit.. All batteries are charged directly by the inverter as they are part of the 24 volt circuit, the equalizer comes into play when 12 volt loads are consuming more power than the 24 volt load to keep the batteries in balance.

That’s the best I can figure by looking at the schematics.

[Archived]

I would like the read a response from Gil after he looks the schematics…

Diane

[Archived]

Michael,

I do believe you are correct. I found a second schematic in
my book which is more of an artists rendering than a true schematic.

This rendering clearly shows that all 8 batteries make up
the equivalent of a single 24-volt battery. The confusing part is the labeling
of the battery banks and the bus bars. I have one bank of 4 batteries labeled
24V Battery Bank which feeds a bus bar labeled 24 Volt Power Bus Bar. I have a second set of 4 batteries labeled
12 V House Batteries which feeds a bus bar labeled 12 Volt Power Bus Bar. There
is of course a third bus bar labeled Ground. The labeling implies they are two
separate banks interconnected only through the Vanner units.

With the batteries installed, it is impossible to manually
trace the battery cables but now that I see it in the drawing I have, I can
also see the connections on the bus bar tying the batteries together.

All that being said, we are still faced with the same issue
of two trace chargers trying to charge one battery and each charger potentially
seeing different battery temps. In my case, I have an upper bank of four
batteries and a lower bank of four, I would imagine the upper battery temp
sensor might register a little hotter than the lower sensor just from normal
heat rising. Interestingly the upper sensor is connected to my #2 inverter and it
is that unit that shuts down. Another interesting point is the drawing I have
shows the BTS glued to the sides of the batteries whereas mine are glued to the
tops of the batteries. Don’t know if that means anything in the real world but
just throwing it out.

Paul

[Archived]

I found the following statement in the TRACE Integrated Power Panel (IPP) guide:

Battery Temperature Sensors (BTS) should be placed on the side of the battery. They transmit temperature information to the charger and adjust the charging rate according to the battery temperature.

1) Locate the battery temperature sensores and route them down through the conduit in the DC disconnect Box to the batteries.

2) Place all sensors onto the side of the same battery (located in the middle of the battery bank) to prevent different charging rates based on temperature variances.

That is how my coach was setup from Vantare, both sensors (one for inverter 1 and one for inverter 2) where taped to the side of the middle battery (between the batteries, not on the end) on the street side batteries. The curb side had no sensors. I moved them to the curb side as those batteries run hotter than the street side by a good 15-20 degrees hotter.

I also read in another Trace guide that the glue on sensor types should not be placed on the top of the battery as they will not read the electrolyte temp properly at that location, they need to be below the top level of the electrolyte. The only sensor that should be placed on the top of the battery is the type that bolts to the battery post, and it should be bolted to the post since the post transmits the temp of the electrolyte through the post.

I played with the max charger amperage today, and it did not work quite like I would like it. I wish it had the feature to disable the charger like the Xantrex RS3000 I installed in my Bluebird several years ago has. The Trace SW is a very confusing solution, setting it to 1 AMP does make it reduce the supplimental power supplied by the inverters somewhat. But it still tends to do it from time to time for no reason at all when the grid is not even supplying 50 amps per leg. But I agree this is where the problem is, it finally does seem to balance itself out as long as I am not using heavy 12 volt DC loads.