Converting to Lithium

[Vermilye]

Well, I learned something I should have realized long before. I decided to hook up to the truck to be sure that the charge line was really dead & not my tester. Guess what? No power tongue jack.

I added the DC to DC converter, and Escape does not run a separate line from the converter to the tongue jack, but taps into the charge wire. The DC to DC converter does not "feed through" backwards, so I'll need to run another line from the converter to the tongue jack.

Oh well, I wanted to feed a wire the length of the trailer , NOT...

[Sean Murry]

Originally Posted by Vermilye

Well, I learned something I should have realized long before. I decided to hook up to the truck to be sure that the charge line was really dead & not my tester. Guess what? No power tongue jack.

I added the DC to DC converter, and Escape does not run a separate line from the converter to the tongue jack, but taps into the charge wire. The DC to DC converter does not "feed through" backwards, so I'll need to run another line from the converter to the tongue jack.

Oh well, I wanted to feed a wire the length of the trailer , NOT...

Hi Jon
Not knowing a whole lot about electronics, if I swap out the converter with the Progressive Dynamics converter as you have done, will I encounter the same problem with the tongue jack, or is the problem you encountered related to some of the other mods you made.

[Vermilye]

Originally Posted by Sean Murry

Hi Jon
Not knowing a whole lot about electronics, if I swap out the converter with the Progressive Dynamics converter as you have done, will I encounter the same problem with the tongue jack, or is the problem you encountered related to some of the other mods you made.

No. The problem was caused by the addition of a DC to DC converter in the truck charge line. If you don't add the DC to DC converter, there won't be a problem.

[Sean Murry]

Thanks for the speedy reply. That is a relief!

[StillCampin]

Originally Posted by Vermilye

Oh well, I wanted to feed a wire the length of the trailer , NOT...

Having just recently worked with relays, I think that with a relay or two you might be able to route battery power around the BtoB to the jacks without compromising the BtoB operation.

Since I'm following your lead, kinda, I know I'll be looking into using relays once I get to that point sometime this September.

[fudge_brownie]

An interesting alternative. Some questions?

• What was your reason for the conversion?
• How did you disable the WFCO from charging the batteries?
• Did you follow some set of instructions?
• Not clear from where to where you ran the #4 wire?
• At a cost of $300 (depending on model) there is no savings versus replacing the WFCO guts, what do you gain other than tow vehicle charging?

Originally Posted by AllanEdie

Jon mentioned using a DC to DC converter to charge his new lithium batteries, and upgrading the standard AC charger to do a better job of charging while plugged in.



I think I did something a bit different, and it has worked well for me. I also used a DC to DC converter (also known as a Battery to Battery Charger - mine is a Sterling). I installed a separate charge circuit of #4 cable with an ATV plug at the truck bumper for disconnecting the trailer. The standard charge wire in the 7 pin setup now just turns the charger on. It is far too light to accomplish much charging. The heavy charge cable supplies the BtoB charger directly. Even with the heavy cable, voltage at the batteries would be too low, and improperly regulated for a proper charge, hence the BtoB which raises the voltage as appropriate for a multi stage charge.



Rather than replace the charge guts of the standard AC converter/charger, I just disconnected it from the battery and DC circuits altogether, and used the output exclusively to drive the BtoB charger. Hence, the only charger the batteries ever "see" is the output from the BtoB. Ditto all the DC trailer circuits - they only get power from the BtoB. When driving, the BtoB charger gets juice from the TV alternator, when plugged in, it gets it from the standard charger.



Basic picture is that if you install a good DCtoDC (BtoB) charger, you do not need to upgrade the guts of the standard charger, just use the standard charger to drive the BtoB.

[AllanEdie]

Thanks for your interest.


My primary reason for using the BtoB in the first place was that with it I get a proper multi stage charge from the TV whenever the engine is running. This cannot be accomplished due to low and poorly regulated voltage at the trailer batteries without a BtoB charger that will raise the input voltage provided from the tow vehicle. Further, the standard wiring for the TV charge circuit is incapable of delivering high charging amps at needed voltage at the trailer batteries, hence the separate charging circuit of battery cable. The cable comes from the engine compartment, positive to the positive battery terminal via a 50 amp fuse, negative to an engine ground bolt. The disconnect plug at the truck bumper is a standard 50 amp plug available at the local auto parts store. The cable size is actually a combination of #4 and #6. #6 alone would likely do the job, but I already had the #4 from my previous camper setup.

Since I already had the Sterling BtoB, and I wanted a proper regulated charge while plugged in to shore power, I chose to use the BtoB rather than new charging guts in the converter to reduce cost, and to stick with the Sterling charge control which I have great confidence in from previous experience with two other models of their BtoB's.



Regarding your question re. rewiring the AC charge unit, the charge unit in the converter is connected to the DC system in the trailer through a single wire between the converter and the DC fuse panel or the battery post, I can't recall which for certain. At any rate, I simply disconnected the feed wire from the converter to the fuse panel/battery, and led it to the input of the BtoB. I then attached the output from the BtoB to the fuse panel/battery where the converter was previously attached. The only thing the converter now does is feed the BtoB, it is no longer connected to anything else. When plugged in to shore power, the converter supplies input to the charger, and the charger feeds the batteries and all DC circuits.



I was not following instructions, I just set it up the way I did because I figured from previous 12 volt work that it should work well, and it does. I did check with Sterling to ask whether the quality of the DC from the converter might be a risk to the BtoB, and they did not expect a problem. Worst case, I figured, was that if it didn't work on shore power, I would be no further behind, I would just have to buy the charger conversion after all.


Anyway, to sum up, whether overkill or not, I wanted a high quality charge from the TV, and the only way to get it was with the BtoB and separate charge wiring. Since I had the BtoB, it was cheaper, and maybe accomplished a higher quality charge control, by using the BtoB rather than doing the charger conversion.



If you do not want effective charging from the TV, the converter upgrade would be quite a bit cheaper by the time you include the cost of cable, fuse and disconnect plug. Also a fair bit less work. I know nothing about the relative reliability of the converter upgrade, but I highly recommend Sterling chargers both for the quality of their products and for exceptional product support.

[fudge_brownie]

Thank you for that very thorough description. As is often said on the forum “everyone’s camping style is different”. You obviously will be towing a great deal to replenish battery, in your situation why wouldn’t the roof top solar be adaquate?

[AllanEdie]

In hindsight, solar while driving probably would have sufficed. I do not have rooftop solar though, the panels are on a telescoping post built into an aluminum storage box. I normally drive with the panels lowered and covered to protect them from rocks. I could arrange to leave them up in a flat position, but I have not done that because it would involve some sort of support on the trailer roof which would require design to accommodate or defeat slight flexing in the tower while on the road.



Had I known how effective the panels would be, I am not sure that I would have considered tow vehicle charging that high a priority. It would not be the first time I was accused of overkill...

[StillCampin]

Originally Posted by fudge_brownie

...why wouldn’t the roof top solar be adaquate?

I'm not Allen but I'll provide my experience.

2 100-watt panels flat on top of my tonneau cover to pwm controller to aux battery in bed of truck used by small 12v compressor freezer. 3-5 driving hours generally between 10 & 3; early Jan. Traveling south on 101, WA to AZ. I did not get sufficient sun on that route to make the difficulty accessing under the tonneau cover worthwhile.

Different route, different time of year, different location all could improve the result. Having no significant draw would help considerably.

[Brian B-P]

Originally Posted by Vermilye

Well, I learned something I should have realized long before. I decided to hook up to the truck to be sure that the charge line was really dead & not my tester. Guess what? No power tongue jack.

I added the DC to DC converter, and Escape does not run a separate line from the converter to the tongue jack, but taps into the charge wire. The DC to DC converter does not "feed through" backwards, so I'll need to run another line from the converter to the tongue jack.

When the cable to the tug is disconnected, does the breakaway switch get power from the battery? I would guess not, for the same reason as the power jack.

[Vermilye]

Originally Posted by Brian B-P

When the cable to the tug is disconnected, does the breakaway switch get power from the battery? I would guess not, for the same reason as the power jack.

I'm moving both the tongue jack & breakaway wiring to a #8 wire run from the battery disconnect switch (a 40 amp fused connection directly to the batteries).

[Mike Lewis]

Originally Posted by Vermilye

I'm moving both the tongue jack & breakaway wiring to a #8 wire run from the battery disconnect switch (a 40 amp fused connection directly to the batteries).

If that connection is "live" all the time it will give the kids in the campground something to play with while you're away.

[Brian B-P]

Originally Posted by Vermilye

I'm moving both the tongue jack & breakaway wiring to a #8 wire run from the battery disconnect switch (a 40 amp fused connection directly to the batteries).

That will work... but breakaway switch connections are usually not fused. No fuse sounds like an electrical hazard, but the idea is to be sure that there is power available; I suppose that if you retract the jack on trailer power at each hookup, you'll know there's power. An alternative is an auto-reset circuit breaker.

[Vermilye]

Originally Posted by Brian B-P

That will work... but breakaway switch connections are usually not fused. No fuse sounds like an electrical hazard, but the idea is to be sure that there is power available; I suppose that if you retract the jack on trailer power at each hookup, you'll know there's power. An alternative is an auto-reset circuit breaker.

I am not running a unfused piece of #8 wire the length of my trailer fed by a pair of batteries capable of producing 1000 amps to a short. The BMS should shut it down at 400 amps after 1/2 a second, but I prefer a fuse.

By the way, unless powered by the truck (which has a 25 amp fuse) the break away switch gets its power through the 40 amp fuse in the stock Escape 21.

[Vermilye]

Originally Posted by Mike Lewis

If that connection is "live" all the time it will give the kids in the campground something to play with while you're away.

It is live all the time in every Escape I know of...

[Brian B-P]

Originally Posted by Vermilye

I am not running a unfused piece of #8 wire the length of my trailer fed by a pair of batteries capable of producing 1000 amps to a short.
...
By the way, unless powered by the truck (which has a 25 amp fuse) the break away switch gets its power through the 40 amp fuse in the stock Escape 21.

Yes, short protection is good, and that's the reason for a breaker.

Escape is apparently counting on the 40 amp fuse blowing being noticed because something else doesn't work (such as the jack, or that the battery doesn't charge while towing)... because we know that almost no one actually pulls the breakaway plug to test for power every time they hook up.

[Vermilye]

Originally Posted by Brian B-P

Yes, short protection is good, and that's the reason for a breaker.

Escape is apparently counting on the 40 amp fuse blowing being noticed because something else doesn't work (such as the jack, or that the battery doesn't charge while towing)... because we know that almost no one actually pulls the breakaway plug to test for power every time they hook up.

When the 40 amp fuse blows, nothing works (unless plugged in or the trailer has active solar). It is the only connection to the battery (other than the inverter).

As to thermal circuit breakers, I've had too many fail to trust them as the sole protection for a direct battery connection. I prefer a fuse, or a non resetting breaker.

[Mike Lewis]

Originally Posted by Vermilye

It is live all the time in every Escape I know of...

That's interesting. It's obvious I don't have a power tongue jack (yet). From this thread I assumed they were powered by the connection to the tow vehicle.

[John in Santa Cruz]

Originally Posted by Mike Lewis

That's interesting. It's obvious I don't have a power tongue jack (yet). From this thread I assumed they were powered by the connection to the tow vehicle.

it connects the vehicle alternator output to the trailer battery for charging while driving. most vehicles have a relay so their side is only powered when the engine is running, but the trailer side is directly connected to the battery etc.

after an emergency situation a couple evenings ago where my trailer became unhitched (tow ball threads stripped!) on a darkening road with narrow shoulders, and realizing my battery powered emergency flashers were worthless. I had an idea for a simple product, a blinker circuit in a 7 blade trailer socket wired so the trailer battery powers the blinker which is sent to the running and brake lights so they all flash like an emergency flasher.