Moving 2021 247BH to Lithium batteries

[AndrewSmith]

Hello

We just got our trailer and took it on a first overnight trip. We were supposed to have power but it was too far for even my extension cord to reach, so it was all off grid.

I was worried that I wouldn't have enough juice for the furnace so we conserved energy like crazy, barely even turned the lights on. The battery lasted /just/ long enough to keep us warm overnight.

This is my third trailer, and I already suspected I'll have to upgrade the battery to be able to camp without a power supply (who thought electric fridges were a good idea?). Now I know for sure. My goal is to be able to power the electric fridge, water pump, and lights for 5 days without shore power or a generator.

I'd like to avoid overcomplicating the upgrade if at all possible. The trailer comes with a 165W solar panel and a solar charge controller with settings for different types of batteries.

I'm thinking to get:

• 2x 170Ah batteries like this: https://ca.renogy.com/renogy-lithium...12-volt-170ah/
• A batter monitor like this: https://ca.renogy.com/500a-battery-monitor/
• An extra charger for home so that I can charge the batteries warm before we head out in the cold, like this: https://ca.renogy.com/20a-ac-to-dc-l...ttery-charger/

Should that be enough? Reading these forums it seems that getting an electrical schematic of the existing build is nearly impossible. And much of it is covered/hidden so I'd have to spend a lot of time tracing each wire making my own. That might not be so bad if it wasn't winter already. Freezing cold and snow/ice/slush has a strong demotivational effect

I'd like to just put the batteris on the tongue where the flooded one was (looks like there's enough room) and leave everything else as-is. But I'm not sure if that's realistic. For example:

1. Does the charge controller in the 247BH only handle solar or does it also regulate charging from 120V? Or does something else handle charging from 120V?
2. Does the original setup have the battery charging from the alternator and if so - will that cause problems since Lithium batteries seem to require a special charging setup?
3. Can I just cut off all connections to the tow vehicle and brakes to make the circuitry simpler? To be honest I can't imagine a situation when the break-away brakes would be of any use. The trailer would have to come off the ball, the chains would have to break as well, and by then I'm guessing everything is upside down already so brakes wouldn't help.

One day I'd also like to set up an inverter but I don't want to bite off more than I can chew and end up with nothing for this year's long may-june trip.

Thanks in advance.

[howson]

Does the charge controller in the 247BH only handle solar or does it also regulate charging from 120V? Or does something else handle charging from 120V?.

Your Transcend also has a device called a converter. The converter uses 120vAC to supply the trailer with 12vDC and also charge the batteries. The converter and solar controller are two separate components but they will work together to charge the current battery.

Does the original setup have the battery charging from the alternator and if so - will that cause problems since Lithium batteries seem to require a special charging setup?.

There's a very small trickle charge that comes in through the 7-pin connector. The problem is the lithium will not charge to it's full capacity and the power coming from the truck is typically so small what is sent will be consumed by your refrigerator.

Can I just cut off all connections to the tow vehicle and brakes to make the circuitry simpler? To be honest I can't imagine a situation when the break-away brakes would be of any use. The trailer would have to come off the ball, the chains would have to break as well, and by then I'm guessing everything is upside down already so brakes wouldn't help..

No. Nyet. Nein. Absolutely under no circumstances or for any reason. Always ensure all the safety devices work as intended and are hooked up for your safety and those around you. I can't even begin to imagine the liability if something were to happen. Not a risk worth taking, regardless of the likelihood

---break---

Before spending money on individual components, determine what you want your electrical system to do. Can your budget withstand doing everything at once or will it be a spiral development? All of these factors will play into the system.

Resources:

Will Prowse's book (worth the $ IMHO): https://www.amazon.com/gp/product/1546567119
Basic RV Electricity: https://www.amazon.com/No-Shock-Zone.../dp/0990527913

Here on this forum (presentations by fellow moderator TucsonJim ) that you'll find
1) In the Electrical channel's Reference Material sub-channel: https://gdrvowners.com/forum/operati...ithium-battery
2) in the Solar channel's Reference Material sub-channel https://gdrvowners.com/forum/solar/r...4-solar-101-v4

Bottom line: easy to spend a lot of money and end up with a system that doesn't work as intended. This is a topic where (unfortunately) each person must do their homework.

Good luck--hope some of this helps.

Howard

[JBill9694]

Just wanted to add that the converter that Howard mentions probably is not engineered to charge lithium batteries and would need replacement.

[TucsonJim]

Just to add to Howard's response regarding disconnecting the brakes.

If the trailer comes off the ball and chains, you need the break away circuit, At 60 mph, the trailer could roll hundreds of feet and into oncoming traffic. The outcome could be horrific. Please, do not consider doing this.

Jim

[AndrewSmith]

Ah, thanks for explaining. So I've got to figure out what converter I have also. Good to know at least that I don't need to be concerned about the 7pin connector.

1) In the Electrical channel's Reference Material sub-channel: https://gdrvowners.com/forum/operati...ithium-battery
2) in the Solar channel's Reference Material sub-channel https://gdrvowners.com/forum/solar/r...4-solar-101-v4

Thanks for the links. I already went through the videos in the first one. The second was a good summary. Any chance a video of this presentation is available somewhere?

[SASurvival]

Andrew, Check out the link for the conversion of your converter, i did this to upgrade my system. i had 2 options, WFCO or Progressive dynamics, this will help for sure not to destroy your lithium. Great name to.
https://www.progressivedyn.com/lithi...acement-units/
Andy Smith

[Guest]

AndrewSmith Andrew, Howard and Jim are the solar kings where they could guide you on a top of the line solar system. I however I am cheap and wanted to boon dock inexpensively so I opted for a Progressive Dynamics Converter, a single 100ah AIMs battery and a Renogy 20amp DCDC converter. Also a Champion 3400 remote electric start inverter generator.
My Imagine fully charged in the morning will run the lights in the daytime and the furnace at night in the late fall and will result in still having 43% state of charge by the next morning. I do not have an electric residential fridge.
The key here is to understand the draw of the residential fridge and furnace and estimate their duty cycle under the worse conditions for your style of boon docking in the cold or heat. Then calculate the ah usage and make an estimate on total battery power needed.
Honestly, if you boondock, a generator will make the difference when the sun is not shining. It is an essential component IMO where the new inverter models are very quiet. With a lithium dedicated converter, a generator will charge that lithium pack with amazing speed so no longer would you need to listen to that all day with a lead acid battery pack. However if you want 5 days without a generator, the total ah usage needs to be calculated to make a decision in how much battery power you need. Don't forget you do need some reserve battery capacity in returning home for the break away function of the brakes.

Lithium batteries will have the best longevity in an environment that we ourselves find comfortable so to mount them on the tongue will work but not well in extreme cold or heat. To place them in the pass-through would be good or if you winter camp, in the living area where they will stay warm, or cool depending on location and conditions.

Take care,

Jim

[AndrewSmith]

Thanks for the advice!

Guest : did you do all this by yourself? I'm feeling more and more comfortable with it as I learn more about the components, but it still bothers me that I don't have an electrical diagram. Grand Design didn't even reply to my request.

I checked and I have a WFCO WF8955 converter. According to its specs it charges in three stages, at 14.4V, 13.6V, and 13.2V. That sounds awefully similar to what a Lithium battery needs. Is there any chance that I would damage the batteries by using it? I don't mind if it takes longer to charge, and the Progressive Dynamics retrofit for the converter is 540$+tax where I live.

Page 6 here: https://wfcoelectronics.com/wp-conte...l-FINAL-RP.pdf

I mean I'll pay for it if it's the only way to keep the lithium batteries in good order. Two of those will cost me over two grand.

I've been thinking of a generator, but I'm very wary of getting one. I have been annoyed so many times on my trips by the generator people. I don't know how they tolerate that amount of noise. I go out there for the quiet I'd rather have no power at all than be stressed by the noise. Can you please suggest some models I could look into that claim to be quiet? Hopefully they don't mean "quiet" like my air compressor is "ultra quiet"

I tried to do a calculation for battery needs but the problem is the numbers are very vague, and not all of them can even be trusted. So I kind of have to do some trials to figure out how much I need. The only trial run so far just confirmed that led acid isn't good enough

What's your DC-DC charger for? Does it save the batteries from bad alternator charging? I'm still thinking to cut off the batteris from the tow vehicle, and install one of those small batteries made specifically for break-away applications. Would make life simpler, especially since I would like to move the big batteries inside anyway.

[Guest]

Thanks for the advice!

Guest : did you do all this by yourself? I'm feeling more and more comfortable with it as I learn more about the components, but it still bothers me that I don't have an electrical diagram. Grand Design didn't even reply to my request.

I checked and I have a WFCO WF8955 converter. According to its specs it charges in three stages, at 14.4V, 13.6V, and 13.2V. That sounds awefully similar to what a Lithium battery needs. Is there any chance that I would damage the batteries by using it? I don't mind if it takes longer to charge, and the Progressive Dynamics retrofit for the converter is 540$+tax where I live.

Page 6 here: https://wfcoelectronics.com/wp-conte...l-FINAL-RP.pdf

I mean I'll pay for it if it's the only way to keep the lithium batteries in good order. Two of those will cost me over two grand.

I've been thinking of a generator, but I'm very wary of getting one. I have been annoyed so many times on my trips by the generator people. I don't know how they tolerate that amount of noise. I go out there for the quiet I'd rather have no power at all than be stressed by the noise. Can you please suggest some models I could look into that claim to be quiet? Hopefully they don't mean "quiet" like my air compressor is "ultra quiet"

I tried to do a calculation for battery needs but the problem is the numbers are very vague, and not all of them can even be trusted. So I kind of have to do some trials to figure out how much I need. The only trial run so far just confirmed that led acid isn't good enough

What's your DC-DC charger for? Does it save the batteries from bad alternator charging? I'm still thinking to cut off the batteris from the tow vehicle, and install one of those small batteries made specifically for break-away applications. Would make life simpler, especially since I would like to move the big batteries inside anyway.

Here is what I have used. Its not important in what the rig needs where main feed wire from your current system can be integrated into a new lithium system. Here is what I have used.

1) https://www.etrailer.com/RV-Converte...s/PD9260C.html
They also make an 80 amp version where based on your total battery capacity, half of this is optimal for charging. So for instance a 100ah lithium battery will be treated kindly at 0.5C for charging or 50 amps. Since the rig tends to consume about 5 amps I use a 60amp charger which is close enough.

2) https://www.championpowerequipment.c...tart-inverter/
Some will use a dual fuel generator that will also use propane but keep in mind capacity will be reduced on propane since the engine will produce less power on propane. Hauling gas is something that some do not like to do so you can make the choice on that. I'm ok hauling 4 gallons of fuel in a quality can.

3) https://www.renogy.com/12v-20a-dc-to...SABEgIO9vD_BwE
Some will use a higher capacity unit where dedicated cabling will need to be routed to your TV battery. You will not want to run this for extended periods at idle due to the lack of alternator cooling on your TV where being underway should pose no issues.

I do not know what your fridge draws but measure the running current in one hour. The amount of running time in one hour is the ah rating minus startup current which you could estimate and add another 10%.

Adding a bunch of $1000 batteries works well but to run the generator as I do for less that one hour in 24hours does not make a case for me adding more batteries. A balance in how you camp needs to be factored where the residential fridge will certainly call for more that one battery, and more generator time. Your solar should help to reduce generator time in full sun.

Jim

[ncitro]

AndrewSmith You've gotten since great advice here. I run a setup similar to Howard but have done some smaller systems for friends and family too. I strongly recommend to most everyone a DC to DC charger, usually even before solar. Unless you're stationary for a long period of time the charger can make a huge difference as it gives you charging while driving regardless of weather.

The thing to keep in mind about generators is since lithium will take a much greater charge rate than lead acid (and all the way to full) it'll equate to a lot less generator run time if needed. This is particularly true if you get the largest converter your batteries will take (the. 5C rule Jim used) I have the champion dual fuel because I knew it would get limited use and I've dealt with enough gummed up carburators in my life that I wanted propane. I've got mine rigged up to the grill port in the trailer so it'll run off of that rather than hauling an extra tank.

If you're not averse to running gas I think the quietest you can get is the Honda, but the champion is only slightly louder. That said I also dislike the noise and don't run it much, a large part of the reason I got the Multiplus.