battery upgrade questions

[Merlin]

It's odd you've seen the WFCO in your camper at a max of 13.7V. That unit has a 3 stage charger with a bulk charge voltage of 14.4.

I can't safely advise you on which circuits should be on each breaker in your WFCO power center without being there in person. I have a Progressive Dynamics power center with the AC outlets and the DC converter on separate CBs in my camper, so I can't send photos that would help.

Perhaps someone else with a WFCO power center will read this and chime in with how theirs is wired.

AC wiring in a camper should not be "guessed". It's a huge safety issue. I'll go back to my earlier post to leave things status quo until next year and your complete redo.

In the meantime, enjoy those 2 big batteries! That's a nice upgrade!

[Gary M]

It's odd you've seen the WFCO in your camper at a max of 13.7V. That unit has a 3 stage charger with a bulk charge voltage of 14.4.

From the research I've done, this charger will only go into bulk mode when the battery is less than 50% and it will only stay in that mode for a short period of time. A lot of WFCO owners upgrade to a Progressive Dynamic charger because of this. The new PD chargers can be manually forced into boost mode for fast charging off a generator. I've never had my battery that low which is why I haven't seen it go into bulk mode. The trailer is only a couple months old.
The Cotek CX1250 was recommended to me as a temp charger by a professional solar installer(Brian Boone) who will be doing my solar install next summer.

I can't safely advise you on which circuits should be on each breaker in your WFCO power center without being there in person. I have a Progressive Dynamics power center with the AC outlets and the DC converter on separate CBs in my camper, so I can't send photos that would help.

Totally understood. I've ordered a Victron BMV-712 Smart Battery Monitor with Built-In Bluetooth so I can accurately monitor my batteries and charger. My latest plan if the WFCO fails to fully charge my new batteries, is to just disconnect the charging portion of it at the "General" breaker, and power the Cotek charger through that breaker instead. That would save me from having to install a sub panel. If the breaker trips easily with use of the AC outlets at the same time, then I think I will move the power to the outlets over to the GFI breaker. I'll have to do more research on that before doing it though. I appreciate all the suggestions! This is turning out to be a real brain buster for something that should be relatively simple to do.

[Steve Sanders]

I've installed WFCO power centers in both of my Quicksilver campers. The directions call for the 30 amp side of the 30/15 split breaker that comes in the first position to be connected to the hot (black) wire in the shore power connection cable to function as a main breaker. This misuses the breaker by "backfeeding" current through it. Backfeeding probably violates most residential electrical codes, but it is common in this application and isn't really dangerous. After all, there is another 30 Amp breaker in the shore power connection box.

The 12 converter is typically powered from the far right breaker, but often has a wire that allows another circuit to be connected to that breaker as well. I don't like that arrangement because it's really just a fancy "double tap" connection that is not the best idea.

If you replace the first 30/15 breaker with a 30/30 breaker and use the left side as the main and the right side to power a subpanel, the bus bar in the WFCO will be protected from the subpanel's current draw. The current going to the subpanel can use just the breakers circuit, that's designed for up to 60 Amps. The full 30 Amps that the shore power cable and supply can supply will be available to both panels, but still limited to a total of 30 Amps.

You will have to move one circuit from the WFCO to the new subpanel, but that can't be avoided.

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[Gary M]

That sounds like a lot of work just to install an AC outlet for my charger. I really want to just disconnect the wfco charger from the gen breaker and connect the new charger to that breaker instead.

[Steve Sanders]

Ok... I see the circuit labeled "gen" in the picture, but I don't understand. Is that providing power to something related to the generator, or is that a back-fed main breaker for feeding generator supplied power to the panel?

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[Merlin]

Ok... I see the circuit labeled "gen" in the picture, but I don't understand. Is that providing power to something related to the generator, or is that a back-fed main breaker for feeding generator supplied power to the panel?

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See reply #5 from DavidM above on the critical safety issue of never connecting a generator directly to the power control center. That "gen" CB is not related to a generator. Garymcclellan described i's use in reply #12. Generators should only be connected to the shorepower input.

[Gary M]

"Gen" is short for "general" not to be confused with "generator". I had to do some research on that myself.

My 15amp "General" breaker is currently powering 4 AC outlets, as well as the charging portion of my WFCO converter/charger.

[Gary M]

On another note, I've gone ahead and ordered the Cotek charger recommended to me, along with 25' of 4awg wire, split loom, clamps, and a victron VMB-712 battery monitor and shunt.

The reason I've decided to go this route is because I have multiple 2 week boondocking trips planned up in the mountains in WA state from Sep-Dec that are very important trips with alot invested in them. I don't want to risk being stuck up there with a charger that can't keep up with my batteries. This Cotek charger will also be better for the batteries in the long run due to its dedicated "AGM" modes of operation. From the research I've done, I have very little faith in my WFCO 30 amp charger.

Thank you all for the inputs and I'll post pics as this project moves forward!

[DavidM]

So you plan to keep your batteries charged while boondocking by powering your new charger from a Honda 2200 genset, right?

Another way is to connect your batteries to your TV's battery with jumper cables and run it for an hour or so at idle.

The direct heavy connection results in a much lower voltage drop than the long 10 gauge or so connector wiring to the TV. You probably will get 30 amps or so with the direct connection vs 10-15 with the connector. Heck do them both at the same time. The lower the voltage drop, the faster the battery will charge.

David

[Gary M]

So you plan to keep your batteries charged while boondocking by powering your new charger from a Honda 2200 genset, right?

Yes, and hopefully not have to run more than a couple hours a day.

Another way is to connect your batteries to your TV's battery with jumper cables and run it for an hour or so at idle.

The direct heavy connection results in a much lower voltage drop than the long 10 gauge or so connector wiring to the TV. You probably will get 30 amps or so with the direct connection vs 10-15 with the connector. Heck do them both at the same time. The lower the voltage drop, the faster the battery will charge.

David

Good idea as a backup plan! Thanks David

[Gary M]

Install is complete and I am more than happy with the results.

I ended up just wiring in an AC speedbox receptacle with #12 romex straight to the General breaker (where the other outlets are hooked up to), to power the new Cotek charger.

There was no need for me to disable the WFCO charger as it plays nice with the new charger. The WFCO just stops charging when the new charger is powered on.

The Cotek was able to charge my batteries from 70% all the way to 100% in less than 3 hours with a max voltage of 14.7(which I recently lowered to 14.4 because the fridge check light was coming on), and a max amperage of 50a. During my testing, the WFCO alone would not put out more than 15a, which is far below the rated charging current for these batteries. The website for the batteries actually has a warning about charging with less than 30-110a, so I am glad I got the Cotek charger!

Batteries were connected in series with 2/0 wire and connected to charger with #4. Grounds from shunt and charger were ran with #4 as well. Added a new battery disconnect, 300a terminal fuse, and 80a resettable fuse for Cotek, Victron battery monitor with bluetooth and iphone app, and I also installed my progressive industries EMS-HW30C hardwired surge protector since i had the distribution panel removed.

No issues so far, here are some pics of the install under the bunk of the 2018 21BHS...

[DavidM]

Glad you got it working well with the new charger. Some observations/suggestions:

1. The new charger charges at 50A when the battery is 70% full and will charge fully in three hours. As I recall you have two 6V GC batteries of about 225 AH. That means that the charge rate must drop as it gets beyond 70%, which is not surprising. It takes a long time to charge FLA batteries the last 15%.

2. The WFCO charger just stops charging when the new charger is on. Again not surprising. The WFCO charger hits its maximum acceptance voltage and it switches to float which is well below what the new charger is putting out, so its charging rate goes to zero.

3. How many amps AC does your new charger draw when it is charging at 50A? If it is less than 13A then you can use a Honda EU2000i generator to power it by hooking up the shore power cord through and adapter to the generator.

4. Looks like there is plenty of room for another pair of GC batteries. That is the next thing I would do. It will extend your boondocking time significantly and might mean you don't have to worry about a generator. Monitor your DC useage with the Victron and make sure you keep the batteries at 50% or greater for best life.

David

[Gary M]

Glad you got it working well with the new charger. Some observations/suggestions:

1. The new charger charges at 50A when the battery is 70% full and will charge fully in three hours. As I recall you have two 6V GC batteries of about 225 AH. That means that the charge rate must drop as it gets beyond 70%, which is not surprising. It takes a long time to charge FLA batteries the last 15%.

Yea, It started dropping from 50 amps at about the 85% point.

2. The WFCO charger just stops charging when the new charger is on. Again not surprising. The WFCO charger hits its maximum acceptance voltage and it switches to float which is well below what the new charger is putting out, so its charging rate goes to zero.

Yes, and I verified by disconnecting the WFCO charger while both chargers were running, and the voltage and current remained exactly the same.

3. How many amps AC does your new charger draw when it is charging at 50A? If it is less than 13A then you can use a Honda EU2000i generator to power it by hooking up the shore power cord through and adapter to the generator.

I forgot to plug in my kilowatt meter before the test, but the Cotek charger came with a 15a power cord. I also have the new EU"2200"i honda that puts out a little more than the 2000's (120V 2200W max. (18.3A), 1800W rated (15A), so im thinking it should be good. True test will be on my trip this weekend

4. Looks like there is plenty of room for another pair of GC batteries. That is the next thing I would do. It will extend your boondocking time significantly and might mean you don't have to worry about a generator. Monitor your DC useage with the Victron and make sure you keep the batteries at 50% or greater for best life.

I was thinking the same thing! although I had a hard time running down these 2 batteries for the test. It took 3 days of running all my DC loads around the clock to get them down to 70%. All lights, fans, etc.. everything minus the furnace as I didn't want to waste propane These batteries are very impressive, even with just 2 of them. I appreciate all the suggestions David! Thanks

[DavidM]

"I was thinking the same thing! although I had a hard time running down these 2 batteries for the test. It took 3 days of running all my DC loads around the clock to get them down to 70%. All lights, fans, etc.. everything minus the furnace as I didn't want to waste propane These batteries are very impressive, even with just 2 of them. I appreciate all the suggestions David! Thanks"

That means you use 10% of 225 AH each day or 23 amp hours a day. That is more than minimal (I use 10-12) but not terribly high. That means with 4 GC batteries you could go 10 days without getting below 50%. Then why worry about a bigger charger and a generator? Do you camp for more than ten days at a time without shore power?

David

[Gary M]

That was just driveway testing with everything running 24/7. I would use way less than that normally. But yea, I'll be out boondocking the entire month of September, and a few other 2 week long trips Oct-Dec. I already have the generator so I may as well use it. I'm also considering getting a portable solar suitcase kit to help out. Problem is that it's very cloudy/rainy up here in WA state at that time of year, hence the need for the generator.

I totally agree with you that 4 of these batteries would be way better, but i'm also a little skeptical about adding more weight to the rear of the trailer. these bad boys are 70+ lbs a piece.