Battery draw down on 2018 Classic

[ChipB]

Originally Posted by uncle_bob

Hi

"...As it is, with 400 usable AH of capacity onboard (the trailer has been modified a bit ...)…"

Bob

Bob,

Curious as to the mods to your trailer that provide 400ah capacity. I'm converting to 2 6v, 220ah in series to boost ah & wondering if that's what you've done?

Thanks,
Chip

[OTRA15]

Chip,

You might want to peruse the topics in these solar etc. forums:

http://www.airforums.com/forums/f37/
[subset of above]: http://www.airforums.com/forums/f448/

Plenty of material to digest.

Good luck,

Peter

FYI/FWIW

[uncle_bob]

Originally Posted by ChipB

Bob,

Curious as to the mods to your trailer that provide 400ah capacity. I'm converting to 2 6v, 220ah in series to boost ah & wondering if that's what you've done?

Thanks,
Chip

Hi

Quick answer is 4 x 100AH Lithium batteries. Since they are Lithium's you get to use the "whole rating" as opposed to half the rating. Yes there are some downsides and many threads that go into all the details.

The real point is that the only "solution" to running a modern Classic purely on batteries for much over a day is to increase the battery capacity onboard. There is no practical way to use the trailer and not have a pretty substantial power drain. It being a rainy day provided an easy way to come up with real world data.

Indeed the sun just came out and the solar *is* doing a much better job. The forecast seems to suggest that will only last for another hour or two. Then it's back to rain and clouds.

Bob

[ChipB]

Thanks Bob, and Peter

Lithium isn't practical for me at this point. Maybe down the road- it sounds like a great set-up, Bob.

I've read through the forums extensively over the past 18 months or so. The best advice I've received has been from those sharing similar situations and experiences. This forum is a great resource.

Is there anyone out there with a 2017 or newer Classic or Classic 33 that has been converted to 2 6v batteries in series? Experiences pro, or con?

Thanks,
Chip

[steverino]

Chip,

I am in the final stages of installing such a conversion, on the 2018 Classic. 2 pairs of Fullriver DC220 6v AGM batteries - one pair in the battery box, one pair under the sofa. Which will yield 440 AHr total capacity, 220 AHr usable. Along with coordinate upgrades in converter and bigger cables between converter and battery banks.

In my opinion, installing just one pair of 6v AGMs will gain you an improvement over the stock flooded cells, but not significantly so.

Steve

[uncle_bob]

Hi

In some years, the Classic's come stock with solar. In that case they come with AGM's as well. The flooded cells rate out at about 80 AH and the AGM's come in at about 100 AH. Either way, you have roughly a day of normal use on the stock batteries. Even bumping that up from 100AH usable to 120 AH usable is working on the roundoff error in the calculations.

With two people, we can run for 7 days on the water tanks. Our objective was to get the battery / solar setup to the point that it could be in that range as well.

Bob

[ChipB]

Originally Posted by steverino

Chip,

I am in the final stages of installing such a conversion, on the 2018 Classic. 2 pairs of Fullriver DC220 6v AGM batteries - one pair in the battery box, one pair under the sofa. Which will yield 440 AHr total capacity, 220 AHr usable. Along with coordinate upgrades in converter and bigger cables between converter and battery banks.

In my opinion, installing just one pair of 6v AGMs will gain you an improvement over the stock flooded cells, but not significantly so.

Steve

Steve,

I went through with the conversion to two 6v Lifelines in series in early May this year. (previously had two 12v Optima Blue Tops in parallel config). The difference is remarkable:

The Optima Blue Tops gave me maybe 6-8 hours in 30-35 degree weather at night, so no solar to account for. All we ran were the Refrigerator, Alde Heat, and an occasional toilet flush during the night, along with Firefly and the other parasitic system draws. Before dawn we were usually right at or slightly above 50%, but often the voltage was just under 12v (causing problems with Alde heat going into Gas Lockout). Many a morning I awoke to a cold trailer and unable to run a generator due to Park generator time restrictions. This was our experience in late October last year at Elkmont Campground in the Smokey Mountains. The Optimas were about 11 months old at this point.

Shortly after the 6v conversion this May I headed to Colorado and dry camped at Mesa Verde. Temps were in the 30s at night, no solar influence. Starting at 100% at 9pm, and again, only refrigerator, Alde, occasional toilet flush during the night, along with Firefly and the other parasitic system draws. At roughly 8am three days running I was at 80% or greater, in a warm trailer.

The real test came when I made it to the North Rim Grand Canyon May 19-21st. No opportunity for solar due to snow accumulation, and night temps 26-28 degrees. In addition to refrigerator, Alde, occasional toilet flush during the night, along with Firefly and the other parasitic systems, I had to run the tank heaters to keep from freezing. Amazingly, after 8 hours I was at 55% and again a warm trailer.


I've also found these batteries recover and recharge much faster and seemingly deeper. I can recommend this conversion.

Given my results, the other conversions, like yours and Bob's, must produce tremendous results!

For the money, and FWIW, this one has worked like a champ for me between recharges.

Chip

[uncle_bob]

Hi

Ok, there's a gotcha .... if you are looking at voltages to figure out your "capacity left", then temperature is a big deal. At sub-freezing temperatures, your battery voltages will be much higher than normal. 12.6V is a dead battery when it is cold.

So you run out and get a shunt based charge monitor. You set it up correctly for two 6V batteries ( = tell it you have 120AH usable) and all is well ... right? Unfortunately not so much. Just as voltages change when it gets cold so does battery capacity. When it's freezing out, you may well only have about 2/3 the capacity you have on a hot summer day. Your 120AH is now 80AH. If you don't have a temperature probe on the monitor (and a few settings done right) even it is lying to you ....

The same voltage effect that makes monitoring tough also makes it tough to fully charge cold batteries. A temperature probe on the charger is a really good thing in this case. Charging can get a shunt monitor confused. The charger runs out of current before the battery is full. The monitor thinks it sees a full charge "current taper" and resets to 100%.

Discharged batteries have another risk in the cold. They freeze at a much higher temperature than fully charged ones. Running a battery way down (like to flat) can get the freeze point up to temperatures you might well run into.

So yes, there are a *lot* of ways temperature can fake you out on batteries. If it's cold out and you are *depending* on the battery bank, you need to be a bit careful.

Bob

[Bill M.]

One thing I reading through this. I would not expect to add any charge to the battery by towing. I know my truck does not add charge when towing. And yes, the lead is powered. I think to get significant charge that way you would need to add a 12 volt to 12 volt charger on the trailer and wiring for it to the truck.

[gypsydad]

Originally Posted by Bill M.

One thing I reading through this. I would not expect to add any charge to the battery by towing. I know my truck does not add charge when towing. And yes, the lead is powered. I think to get significant charge that way you would need to add a 12 volt to 12 volt charger on the trailer and wiring for it to the truck.

I moved to Trojan 6V last summer...night and day, and they do charge while towing.

I ran our furnace while boondocking in 30-32 degree weather earlier this month in the Tetons a few nights Showed 12.6v when I went to sleep and woke up to 12.5. Cycled heater on at 56 degrees to 60 a few times, and all worked fine. We camped 4 nights in Tetons and 2 nights in Yellowstone, with no battery issues. Friend traveling with us has same Trojans on his 23'D, and he also had same experience/voltage...

My OEM Interstates last year went down to 11.6 first night using furnace...love the Trojan 6V's.

[uncle_bob]

Hi

Another thing to consider in all this: Battery chemistry / plate composition *does* vary from type to type. 12.6V with this composition may be one level of charge. With a different makeup, 12.6V may be a *very* different level of charge.....

------

Truck power lead charging is highly variable. One truck comes stock to do it all, the next one needs this relay or that fuse plugged in here or there. The next one does it one week and then goes on strike for the rest of the month .... who knows why.

Even when you *do* get a voltage on the pin, you have (maybe) A 60' round trip of number 10 wire to do the charging through. Your alternator voltage varies depending on engine RPM and a bit on the state of charge on the truck's battery. How much current you get to the trailer batteries in this or that state .... who knows.

If indeed you have Trojan's that want a ~15V charge voltage, that's not likely to happen off a truck alternator. There's not a lot of gear that is happy with that sort of voltage level. A DC/DC converter may be your best bet in that case.

There *is* a flip side to all this. You could have a very short run / fat wire setup in the truck and a "hot" alternator (voltage wise). The circuit is likely fused at 30A. As the Sprinter guys have found, that may be more than your alternator really wants to put out on a 100% duty cycle basis ....

Lots of variables ....

Bob

[gypsydad]

Originally Posted by uncle_bob

Hi

Another thing to consider in all this: Battery chemistry / plate composition *does* vary from type to type. 12.6V with this composition may be one level of charge. With a different makeup, 12.6V may be a *very* different level of charge.....

------

Truck power lead charging is highly variable. One truck comes stock to do it all, the next one needs this relay or that fuse plugged in here or there. The next one does it one week and then goes on strike for the rest of the month .... who knows why.

Even when you *do* get a voltage on the pin, you have (maybe) A 60' round trip of number 10 wire to do the charging through. Your alternator voltage varies depending on engine RPM and a bit on the state of charge on the truck's battery. How much current you get to the trailer batteries in this or that state .... who knows.

If indeed you have Trojan's that want a ~15V charge voltage, that's not likely to happen off a truck alternator. There's not a lot of gear that is happy with that sort of voltage level. A DC/DC converter may be your best bet in that case.

There *is* a flip side to all this. You could have a very short run / fat wire setup in the truck and a "hot" alternator (voltage wise). The circuit is likely fused at 30A. As the Sprinter guys have found, that may be more than your alternator really wants to put out on a 100% duty cycle basis ....

Lots of variables ....

Bob

UB; as you know, this topic (TV charging batteries on your TT) has been covered several times on the Forum. Several folks only use their TV to charge their batteries, instead of a generator when camping/boondocking. I do remember having to add a fuse on my 2012 F150 EB to charge my battery while traveling which also powered my 3 way refrigerator in a Casita I owned between AS #1 & AS #2...I was in Canada and remember calling my Ford dealer in Texas to find out why my refrigerator was not getting power...he told me which switch/fuse to buy and where it went. He said Ford did not include a fuse in that slot on the F150 at the time, because of cost and not everyone tows a trailer! Go figure! My F250 does have it and works fine...

I haven't heard the other claims you mention of intermittent charging or lower charge due to wiring. I suppose one could measure the voltage while hooked up while revving the engine in park to check the voltage/current output at the battery.....but not sure I'm that "geeky" yet...I know for my use, the batteries stay topped off while driving and everything works fine.

[uncle_bob]

Hi

If you read through all the multitude of "charging off the truck" posts, people do indeed run into limited charge current in the < 10A range. The reason *why* is indeed the length of wires involved.

Bob

[Froglips]

Originally Posted by gypsydad

I do remember having to add a fuse on my 2012 F150 EB to charge my battery while traveling which also powered my 3-way refrigerator in a Casita I owned between AS #1 & AS #2...I was in Canada and remember calling my Ford dealer in Texas to find out why my refrigerator was not getting power...he told me which switch/fuse to buy and where it went. He said Ford did not include a fuse in that slot on the F150 at the time, because of cost and not everyone tows a trailer! Go figure! My F250 does have it and works fine...

I have to say this surprised me. You didn't change anything else but added a fuse? I have a 2013 F150 EB. What you are saying is that one of the seven pins in the trailer connector is a charging pin. However, I have got the truck owner's manual in front of me and I will report back if there is a charging circuit that needs a fuse. In my experience, my truck does power the trailer.

[gypsydad]

Originally Posted by Froglips

I have to say this surprised me. You didn't change anything else but added a fuse? I have a 2013 F150 EB. What you are saying is that one of the seven pins in the trailer connector is a charging pin. However, I have got the truck owner's manual in front of me and I will report back if there is a charging circuit that needs a fuse. In my experience, my truck does power the trailer.

Yes, this is an old issue documented on several Ford F150 threads...

https://www.fordf150.net/forums/view...?f=88&t=126832

Your dealer should be able to help if you can not find the info in this thread. Crazy, it's not included...perhaps has to do with if the truck has a certain "option package"? What ever the reason, good to know...nothing worse then having a dead battery on your TT!

[Froglips]

Originally Posted by gypsydad

Yes, this is an old issue documented on several Ford F150 threads...

https://www.fordf150.net/forums/view...?f=88&t=126832

Your dealer should be able to help if you can not find the info in this thread. Crazy, it's not included...perhaps has to do with if the truck has a certain "option package"? Whatever the reason, good to know...nothing worse than having a dead battery on your TT!

Ah, thanks for the link. It would appear after quite a bit of reading that the difference is whether a truck has the Max Tow Package. It appears pretty consistently that if your truck has that package that Ford put in the parts and pieces to charge the TT while the TV is running. Does make some sense as to why would one order the Max Tow Package if you weren't going to tow something.