2013 T@B Wiring Diagram including TriMetric Battery Meter Shunt and Noco Genius Battery Charger

AldebaranJill · October 2016

I used that diagram of Rick's as a starting point, and then traced every single wire by hand.
Note this shows the electrical mods that I installed:
1. Trimetric Meter (with shunt)
2. Noco Genius Charger
3. Cut Off Switch
4. 2nd 12 Outlet

Happy to answer any questions anyone may have. It's been a labor of love.
Jill

ScottG · October 2016

A labor of love, no doubt--cool diagram!

Why install the NOCO Genius Charger? Since it still requires 120V, does it confer some advantage over the converter's built in charger?

AldebaranJill · October 2016

Yes, after installing the TriMetric and doing lots of testing under all sorts of discharge states, and meauring battery state of charge with a hydrometer - I proved that the WFCO 8735 was never, ever, ever, ever, fully charging the battery I had (Trojan SCS150) because it never, ever, ever went above 13.6V. This is a 110AH battery that's Group 24, so it fits into the existing box. I didn't want to do two 6V batteries due to weight.

I spent hours on the phone with Trojan, Trimetric, and WFCO. While the WFCO literature claims it goes above 13.6V, it just doesn't do that in our small trailer environments. Again, this is not theory, this is empirical data. I spent months running tests, sitting on my trailer, watching, writing down data.

What was happening was the WFCO was charging to about 70% and simply could not do any more. At 13.6V you will never fully charge a Trojan battery that requires 14.8V. I was going on dry camping trips with what I thought was a fully charged battery, but it wasn't. And because I was never fully charging the battery or keeping it above 80% when in storage, I was killing them. Took me two years of slowly damaging batteries and wondering why I always ran out of power, before I found the right combination of people to assist me (a battery dealer who would let me run tests in his shop and was willing to loan me batteries and charges to take home to experiment, and Bob the Solar Guy in Montana - to help me fully experiment to find the issue.) During these experiments I realized my dealer had miswired the Trimetric!

The charging is now done by the Noco Genius, and it goes up to 14.8V, and that keeps the Trojan battery nice full and happy. When I go on weekend trips, I only use 20% capacity, because I'm leaving home with a healthy, truly 100% charged battery. And the only way you know this, is to measure the specific gravity of the cells. Voltage is not an accurate measure of state of charge.

So yes, the Noco Genius was the only solution I could find that would get to 14.8 V and hold it there till they were really really fully charged. I mounted it under the fridge and plugged it into the 120V outlet under cabinet. When it's parked at home, it's always on, keeping the Trojan's happy.

Thanks for asking! It has been a labor of love!

ChanW · October 2016

AldebaranJill, your diagram is great. Very interesting to see. Thanks for sharing your research.

I'll have to see if we have the same model WFCO, and see what its output is, at various states of charge. You've got me curious now!

You have 'Fridge' on F6, the battery charger fuse. That confuses me. Is that right?

Also,which model Noco Genius did you use?

Sharon_is_SAM · October 2016

Wow, Jill! I have read Handy Bob as well. If you can't rely on voltage as a measure of charge, and must check the sp. gravity, how do you measure state of charge with an AGM? So, the Noco effectively functions as an AC charge controller much like a solar charge controller in that it helps regulate the voltage that charges the battery?

Sharon

ColoradoJon · October 2016

Mmm hmm! I had the same problem with the built in converter on my 2017 not being able to fully charge my dual 6V setup. I mentioned something about it in a previous post and was met with... um... resistance from others.

I use a Pro-Logix PL2320 charger now for battery charging. The converter only runs lights when I am home and connected to power

Just confirming - if you disperse camp make sure to fully charge your battery with a good, 3 stage charger!

ScottG · October 2016

Thanks for the excellent explanation, @AldebaranJill. Through this board (and the school of hard knocks) I learned a lot about battery management when I got the T@B two years. However, I'm only a running a basic system with a group-27 flooded cell and 100W solar panel, so most of the high-capacity/high-tech stuff is still a mystery to me.

Do you use solar at all, or do you rely solely on your high capacity for multi-day dry camping? If you do use solar, do you experience the same issues with inadequate charging voltage?

AldebaranJill · October 2016

ChanW said:

AldebaranJill, your diagram is great. Very interesting to see. Thanks for sharing your research.

I'll have to see if we have the same model WFCO, and see what its output is, at various states of charge. You've got me curious now!

You have 'Fridge' on F6, the battery charger fuse. That confuses me. Is that right?

Also,which model Noco Genius did you use?

@ChanW, Yes, the fridge being on F6 seemed wrong to me as well, and I have not traced the wires, but it only turns off when that fuse is pulled out, so there's a relationship there, but I agree, it seems suspicious, which fuse is yours on?

I am using the 15 Amp (Genius NOCO Genius G15000 12V/24V 15A Pro Series UltraSafe Smart Battery Charger https://www.amazon.com/dp/B00PKIBVU0/ref=cm_sw_r_cp_tai_rMGfybHM8GJD8)
I select the 12V Cold/AGM charging mode.

AldebaranJill · October 2016

SAM said:

Wow, Jill! I have read Handy Bob as well. If you can't rely on voltage as a measure of charge, and must check the sp. gravity, how do you measure state of charge with an AGM? So, the Noco effectively functions as an AC charge controller much like a solar charge controller in that it helps regulate the voltage that charges the battery?

Sharon

@SAM Hmmmm, that's a good question. I suppose you can't. Handy Bob says "Buy AGM only if you cannot get at them for maintenance or cannot vent" so I followed that advice and didn't pursue AGM..

I don't know how Solar Charge Controllers work, but I thought they can only put into the battery what they are capturing from the sun at the moment. The Noco Genius detects the approximate battery state of charge (via voltage), and then goes through a pre-programmed charging algorithm to get it to 100%. The Noco, in my system, was intended to replace the WFCO's job.

rfuss928 · October 2016

ColoradoJon said:

Just confirming - if you disperse camp make sure to fully charge your battery with a good, 3 stage charger!

Just to be clear, the WFCO converters are "a good 3 stage charger"

The manual clearly describes the three stages and the conditions that determine which stage is active.

Converter Operation Modes
All WFCO power converters are automatic three-stage switching
power supplies. The converter senses which mode it needs to be in by
checking the RV system voltage.

The three modes/stages of operation include:
Absorption mode/Normal operation
Nominal battery charge and supplies power to appliances
Bulk mode/Charge mode
Fast battery charge and supplies power to appliances
Float mode/Trickle charge
Trickle battery charge during storage

Absorption Mode: During this mode, the converter output is in the
13.6 Vdc range. This is the normal operation mode. This mode
provides the 12 Vdc and current required by the 12 Vdc RV appliances,
as well as slow charging the battery.

Bulk Mode: When the converter senses that the RV system voltage is
less than 13.2 Vdc (equivalent to less than 50% of battery charge), the
converter will automatically go into the “Bulk mode.” In this mode, the
output voltage of the converter will switch to 14.4 Vdc for a maximum
of four hours. If the converter cycles between “Absorption and Bulk
mode,” there could be a shorted battery cell or other issues.
If the output voltage drops below 13.2 Vdc, the converter automatically
changes to a “Bulk mode” 14.4 Vdc (unless the converter is in overload
condition). There are two signs of an overloaded converter:
Low output voltage, and full converter fold back or shutdown. In both
cases, the converter will automatically turn ON, once the complete load
is removed. For low output condition, removing the extra (over the
current rating) load will be sufficient. If it is impractical to remove all
the load, resetting the main breaker will have the same effect.

Float Mode: If the RV is not being used for approximately 48 hours,
with a “no load” condition and the shore power is plugged in, the
converter will automatically go into the “Float mode.” In this mode,
the converter is charging the battery with a trickle voltage of 13.2 Vdc.
When the converter senses a demand (by turning on lights), the
converter automatically returns to the “Absorption mode” 13.6 Vdc

8 months of the year, it, along with my Morningstar solar controller, maintain my dual AGM batteries in fine condition. I'm good for 3-4 days without hook-up or solar. The 12v fridge is the main draw and limiting factor. Solar makes our off grid time basically unlimited.

When stored for the winter I use a (BatteryMinder) battery maintainer with a desulfation pulse.

The batteries have just completed their sixth camping season and are likely to be back in service next spring.

AldebaranJill · October 2016

ScottG said:

Thanks for the excellent explanation, @AldebaranJill. Through this board (and the school of hard knocks) I learned a lot about battery management when I got the T@B two years. However, I'm only a running a basic system with a group-27 flooded cell and 100W solar panel, so most of the high-capacity/high-tech stuff is still a mystery to me.

Do you use solar at all, or do you rely solely on your high capacity for multi-day dry camping? If you do use solar, do you experience the same issues with inadequate charging voltage?

@ScottG After many discussions with Handy Bob, I decided not to pursue solar until after I had fully gotten my battery charging solution and TriMetric wiring totally redone. When the dealer installed the TriMetric, they put it under the seat and tapped into my system in a location where (because of the T@B wiring) missed ALL of the loads on the blue wire! So I have not pursued solar yet, because so far, with a fully charged 100AH battery and being able to precisely see how many A each appliance uses, I haven't had to revisit solar.

But your question is a really good one, I would have to do experiments with the TriMetric to see what solar could actually do for me, in the generally cloudy Pacific Northwest. I took a 3 day trip recently and I only used 20% of battery capacity, so I'm thinking I could probably go a week (depending on how much furnace I needed). I would make it a project and re-read Handy Bob's material and go through this forum for advice :-)

AldebaranJill · October 2016

ColoradoJon said:

Mmm hmm! I had the same problem with the built in converter on my 2017 not being able to fully charge my dual 6V setup. I mentioned something about it in a previous post and was met with... um... resistance from others.

I use a Pro-Logix PL2320 charger now for battery charging. The converter only runs lights when I am home and connected to power

Just confirming - if you disperse camp make sure to fully charge your battery with a good, 3 stage charger!

@ColoradoJon Battery debates do seem to get really passionate. People kept telling me the WFCO 8735 was working just fine, and that may be the case, it's just that it was not able to fully charge my batteries, which leads to early battery demise. Without support from my local battery dealer and Handy Bob, I would never have found a solution, and would have just kept killing batteries, year after year.

It's so true, leaving home with a truly fully charged battery is the key. :-)

ScottG · October 2016

rfuss928 said:

...
Bulk Mode: When the converter senses that the RV system voltage is
less than 13.2 Vdc (equivalent to less than 50% of battery charge), the
converter will automatically go into the “Bulk mode.”
...

Suspicious of this statement, I contacted WFCO and they confirmed a typo in both the manual and in the online FAQ. "Bulk mode" activates when the battery voltage drops below 12.2 volts (not 13.2 volts).

So, the converter normally puts out 13.6 volts--well below the 14.8 volts ColoradoJon and AldebaranJill claim they need to get their batteries to full capacity.

AldebaranJill · October 2016

Correct, in my experiments, the WFCO always put out 13.6V and the A varied. I want to clarify that I'm not "claiming" my Trojan SCS150 needs 14.8V, this is from the Trojan specs.

http://www.trojanbattery.com/pdf/datasheets/SCS150_Trojan_Data_Sheets.pdf

rfuss928 · October 2016

12.2 is the correct value for 50% charge and where the WFCO "Bulk Mode" is actually activated - 14.4v for four hours. If your battery never gets that low, you may never activate that mode.

14.8v boils and stirs the liquid electrolyte - desirable in some battery designs and why they need to have the liquid "topped off" regularly. This high voltage is damaging to gel electrolyte and AGM batteries and is usually limited to 14.1 - 14.4v in their charge cycles.

Understanding the specifics and details of all the components of your system is key to safe and efficient operation.

The WFCO converters are a good general purpose unit for the typical deep cycle batteries installed in most RVs and the typical appliance loads they support when on shore power. If you make changes in the system, the interaction between all the components needs to be carefully considered and necessary adjustments made.

Not many T@B owners are going to put the level of time and effort into their battery and charger as some of us have.

AldebaranJill · October 2016

@rfuss928 - My WFCO8735, would not go into Bulk Mode, ever, regardless of the battery's voltage. Please understand that I've tested this, I have actual data. I would create different states of charge, and then charge them while watching the WFCO via the Trimetric. It's max was 13.6V, and the amps would eventually go to nearly nothing. I think it's important to differentiate between what may be written about WFCO, in theory, going into Bulk Mode, and the actual data I have taken, proving that in my T@B, this never happened.

I also think it's important to note that for my Trojan, 14.8V is not about topping it off. For my battery, 13.5V is Float, so the WFCO being at 13.6V is a fundamental problem. I don't even recall what the original battery was and what it's spec was, but Trojan's specs are very clear about it needing 14.8V for the majority of it's normal charging cycle. They are also clear that batteries that are not stored with at least 70% (in other documents 80%) charge, will suffer performance degradation.

rfuss928 · October 2016

AldebaranJill - Both WFCO 8725s I have do run all three modes. I regularly observe 14.4-14.6v and 25-30A when recharging after a stint of off grid camping. I suspect a problem with your unit and would not generalize that "it just doesn't do that in our small trailer environments". It is misleading to suggest all WFCO converters perform like the one you have observed.
The "topping off" I mention is referring to the water that is lost from the electrolyte boiling during the high voltage charging process. A very common maintenance requirement in wet cell deep cycle batteries.
Have fun!
Bob

Michigan_Mike · October 2016

Interesting stuff and mine's working fine too..... smilie

AldebaranJill · October 2016

These trailers seem to all be different individuals

wizard1880 · October 2016

I'm with AldebaranJill, no love from the WFCO 8735 for bulk mode. I have 2 golf cart batteries, and even with 12.2v, no bulk charge.

Users on dozens of other RV forums have the same experience. What they say is the converter voltage *under charge* must drop under 13.2v. Even with your battery reading 11.9v, once the charge is turned on, it jumps to 13.3+ immediately, and this is when it reads the voltage state to determine the mode. Poor design in my opinion.

Others have been able to get boost mode by applying a 50a or so load to the battery immediately when you plug the converter in, with a low battery.

I use an external 50a charger to do the "real" charging when I get home from a trip.

AldebaranJill · October 2016

@wizard1880 is correct, there are many reports of similar issues with the WFCO. I found them when I researched the issue I was having. I saw the folks who said they had to trick it into going into bulk by turning on loads. This was also mentioned by the WFCO person I spoke with. When turning on every appliance I had failed to cause it to go into bulk, I didn't want to assume replacing it would fix my issue. Buying a charger that I could guarantee 14.8V was the best solution for me.

50 A, very sweet! I think I just drooled a little.

Michigan_Mike · October 2016

Each to his own! Mine works fine, my battery is good, charged and healthy and I do a lot of camping therein and don't sweat the small stuff! I've owned 4 Little Guy trailers and have never experienced any issues with a WFCO converter, nor its ability to provide the proper charge attributed to its rating. If there was a serious issue with the WFCO converters and batteries were experiencing failures on equipment that comes stock on these trailers it would have surfaced by now. So if any of you feel strongly that your converter isn't performing to specifications or as you feel it should, you need to contact the factory and discuss the issue with them.

ColoradoJon · October 2016

My WFCO doesn't go into bulk mode, either. 13.6V absorption mode is the best I have seen and that simply is not enough voltage to charge to 100% in a 'reasonable' amount of time. Yes, if left in this mode for enough time it will eventually charge. Maybe.

The WFCO works great for standard run of the mill marine hybrid batteries and works for most people. For my use it does not.

@rfuss928 - the WFCO is an 'ok' 3 stage charger - good enough for most needs. It does not have a high voltage output in bulk mode nor does it have temperature compensation, which is something I need here in Colorado. For high reserve capacity battery systems it simply does not perform well.

Nomad · October 2016

Sorry, no offense but I read these threads and wonder how in the heck I get by with my little battery and minimalist, stock set up. :-)

ScottG · October 2016

Nomad said:

Sorry, no offense but I read these threads and wonder how in the heck I get by with my little battery and minimalist, stock set up. :-)

Maybe you don't get by--it's all just a lie based in self-deception and denial. ;-)

Nomad · October 2016

Na - Almost always been nice and comfy - Other than the fridge problem, all has worked out well. And 85-90% has been dry camping, boondocking. Of course solar is my saviour. And my backup generator is there of course :-)

ericnliz · October 2016

I'm with PXL, solar rocks! Never, ever had any issues with not enough charge on the battery. For that matter, I'm with Mike as well, never had an issue with the converter either. I guess this is another of those " to each their own" issues. Happy camping, and what ever you do, don't check the charge with your tongue!

Verna · October 2016

Solar for me, too. My snowbirdding friends, for the most part, are solar also.

I'm in the process of setting up my sister's 24' RV with as simple of solar as I have found (I know my sister...it has to weigh very little and be inexpensive and plug and play and I have hers picked out), but what can easily keep her dual house batteries charged. (The monster is sitting in my driveway now for two days/nights charging her house batteries after she let them run down again in the storage lot.).

jcfaber1 · October 2016

When camping, I rely on the solar charge controller to properly charge the batteries. When we get home I use a charger to top off the batteries prior to storage. I do think the WFCO is not as thorough as the separate charger.
John

Ratkity · October 2016

Hey, @ericnliz... did you know you can easily check a little bitty 9v battery if it has a charge by sticking your tongue on both prongs?

Nomad · October 2016

So that's the reason you are the way you are Ratkity :-)

2013 T@B Wiring Diagram including TriMetric Battery Meter Shunt and Noco Genius Battery Charger

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