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Need to add Lithium Batter and charger to 2019 RP1

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Forum Name: Podmods, Maintenance, Tips and Tricks
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URL: http://www.rpod-owners.com/forum_posts.asp?TID=15588
Printed Date: 06 May 2024 at 4:26am
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Topic: Need to add Lithium Batter and charger to 2019 RP1
Posted By: Marvin
Subject: Need to add Lithium Batter and charger to 2019 RP1
Date Posted: 23 Jan 2023 at 11:19am

I’m going off grid and want to install a 200 Amp Lithium battery and 200What Solor panels.   Because its Lithium I need to use a Lithium charger.  So this present three issues as I see it.

1.      1. Bypassing/disconnecting the existing lead acid battery charger in the Panel (?).

2.      2. Disconnecting/replacing the existing 120 to 12 vote converter so it does not interfere with the Lithium charger and Lithium battery.

3.      3. Tieing the new 12 vote solar system into the RPod 12 vote system, which I assume is currently running off the existing 120 to 12 vote converter that is also charging the lead acid battery.

Of course I will be using a Solar Controller for the panels as well.

I hope I have explained this correctly.

NOTE:  Yes the Trailer comes with so called “Solar Ready” but that’s a bad joke as I understand it because its just a way to plug a external portable panel into the side plug, but there is no Solar Controller to prevent over charging the battery.  So, I will not be using that existing system unless someone can provide information to the contrary.


Any help is appreciated.  Thank you.



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Marv

2019 RP178 Highly Modified
2022 Subaru Outback Wilderness Turbo Charger



Replies:
Posted By: offgrid
Date Posted: 23 Jan 2023 at 1:12pm
Hi Marv, and welcome.

Heres some comments. If I understand what you're wanting to do correctly, your items 1 and 2 are one and the same. The converter is just another name for the ac to DC battery charger.

And yes you'll want to replace that. While all Lithium batteries come with a BMS (battery management system) which should protect the battery from over/undercharge, operating at too high or too low temps, it should be considered a last line of defense only. So you should remove the converter/battery charger and replace it with one properly set up to manage Li battery charging. There is a direct replacement made by WFCO whivh made the lead acid converter you have now. Progressive dynamics also makes them.

Re your question 3 you can connect your solar charge controller directly to the battery (via an appropriate fuse, located at the battery, not the solar end). Be sure to get one with the appropriate lithium setting. And yes the solar ready option is just a couple of wires. It only adds resistance losses, doesn't really add and benefit.

There is also a 4th electrical connection to consider. You will either need to disconnect 12V tow vehicle power from your 7 way towing connector or if you need that change source, install a DC to DC converter to manage the voltage difference between your TV batters and rpod battery. This is because your alternator, like the converter, isn't set up for lithium charging.

One other consideration. Lithium batteries cannot be safely charged when too cold, so if you will be camping in sub freezing temps you will either need to keep the batteries in the heated space or buy ones that are self heating. It's usually preferred to keep them in the heated area because self heating wastes energy

Have fun on your off grid adventures.



-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: Marvin
Date Posted: 23 Jan 2023 at 1:40pm
Thank you Offgrid for all that.  Just what I'm looking for. I will check out all your information.

One note... one of my upgrades is to add a tongue box that will hold the Propane tank, leveling and towing gear.   The battery will be relocated back about 2.5 feet to inside the RV under the front seat/bed.   I'll probably insulate that compartment outside walls while I at it just for the reasons you stated about the cold, especially here in the NW and especially the mountains we love so much.  

Hummm... I was wondering about the 12V tow vehicle power from my 7 way towing connector, just forgot to mention it.   Problem is... I run with my headlights on to supply power to the RV clearance lights that also power my add-on Rear View Camera that is very handy when passing and backing up.  It therefor is only on when I'm driving the rig.  GOT ANY IDEAS ON THAT?

I'll take before and after photos and post when done.




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Marv

2019 RP178 Highly Modified
2022 Subaru Outback Wilderness Turbo Charger


Posted By: offgrid
Date Posted: 23 Jan 2023 at 2:06pm
The rpod running and brake light circuits are independent from the line supplying charge to the Rpod battery, so all your lights and backup cam will still work even if you disconnect the charge circuit which is pin 4.

But if you want to charge your new battery while kn the road you'll need a DC to DC converter, which should be connected directly to the trailer end of pin 4 before anything else splits off that line. DC/DC converters are available inexpensively on Amazon and elsewhere. If you choose to do that, get one around 20A with an output voltage matching the charge spec of your battery. And, be sure to disconnect it immediately upon setting up camp unless it already cuts off with your ignition, or it will continue to discharge your start battery.

-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: Marvin
Date Posted: 23 Jan 2023 at 2:42pm
Ok... Great advise... I've heard of them but was not sure how that worked. Thanks for explaining that.

-------------
Marv

2019 RP178 Highly Modified
2022 Subaru Outback Wilderness Turbo Charger


Posted By: StephenH
Date Posted: 23 Jan 2023 at 3:51pm
Check my mods (link in signature). I have done what you are proposing. I have written it up with pictures.

You did not say which model RPod or more specifically, which model power center you have. If you have the WFCO-8955, you can swap out the converter section for a WFCO-8950L2-MBA, which is the proper board for Lithium batteries. That is what I did. I also installed a Renogy 20A DC to DC charger. I chose to run a dedicated 12V circuit for the TV and the RPod to power this and disconnected the wire from the Bargman 7-way connector at the junction box under the front corner. If the TV you have has a heavy-duty enough wire running for that, you could disconnect the wire and then run a dedicated line from that point to your DC to DC charger as Offgrid suggests. The way I did it, I have a battery isolation solenoid so when the truck is shut off, the circuit is not energized so it can't feed back through to the TV. 

I did all of this because the Frontier has an "intelligent" charging circuit and the LiFePO4 battery was fooling it into thinking the battery was charged. I would arrive with the LiFePO4 battery at less of a charge than when I left the house. With the separate circuit, this solved the problem and both the Frontier and RPod get properly charged.


-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: Marvin
Date Posted: 23 Jan 2023 at 5:16pm
2019 RP178.   
WF-8735/8740.  I have a phone call into WFCO now to see What unit I may be able to swap in.
Not using the TV... we go to the great outdoors to enjoy the out doors... that's Live...  Much better than TV!!!

Thanks for the Renogy 20A DC to DC charger advise.  Will do.
Will ckout your link later tonight.  Gotta run now.


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Marv

2019 RP178 Highly Modified
2022 Subaru Outback Wilderness Turbo Charger


Posted By: StephenH
Date Posted: 23 Jan 2023 at 6:01pm
Sorry, TV in this case means Tow Vehicle, not Television.

-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: Marvin
Date Posted: 23 Jan 2023 at 6:32pm
Thanks for explaining that... now it makes sense.   A buddy of mine did something similar.

Makes for a good chuckle.   


-------------
Marv

2019 RP178 Highly Modified
2022 Subaru Outback Wilderness Turbo Charger


Posted By: offgrid
Date Posted: 24 Jan 2023 at 4:14am
Originally posted by StephenH


Check my mods (link in signature). I have done what you are proposing. I have written it up with pictures.
You did not say which model RPod or more specifically, which model power center you have. If you have the WFCO-8955, you can swap out the converter section for a WFCO-8950L2-MBA, which is the proper board for Lithium batteries. That is what I did. I also installed a Renogy 20A DC to DC charger. I chose to run a dedicated 12V circuit for the TV and the RPod to power this and disconnected the wire from the Bargman 7-way connector at the junction box under the front corner. If the TV you have has a heavy-duty enough wire running for that, you could disconnect the wire and then run a dedicated line from that point to your DC to DC charger as Offgrid suggests. The way I did it, I have a battery isolation solenoid so when the truck is shut off, the circuit is not energized so it can't feed back through to the TV. 
I did all of this because the Frontier has an "intelligent" charging circuit and the LiFePO4 battery was fooling it into thinking the battery was charged. I would arrive with the LiFePO4 battery at less of a charge than when I left the house. With the separate circuit, this solved the problem and both the Frontier and RPod get properly charged.



StephenH, while the rest of your Li conversion write up is right on the money in my book, I'm not understanding your reasoning for needing to install a separate connector for your Li battery from the TV.

We've had this discussion before a bit but there still seems to be some confusion. Maybe just on my part.

I'd like to get to the bottom of it because I think that extra connector is a complexity and potential failure point that will be a turn off for many folks, and I've not heard of other folks needing to do it.

A DCDC converter connected at the trailer side of pin 4 should give you up to 30 amps (the Bargeman connector current limit) which should be plenty for most uses, without needing another connector.

You can either feed that pin on the TV side through the existing conductor, or if that doesn't supply what you need because of current limitations or a confused intelligent charge circuit or some other reason, you can disconnect it and run another 10 gauge wire from the TV battery via a 30A thermal reset breaker. That is standard materials and procedure when you install an aftermarket 7 way trailer connector kit, Ive done it on 3 or 4 TVs now, probably you have too.

Wouldn't you have to do the same thing with a separate connector to the trailer anyway? Sorry but I'm just not seeing how a second connector adds any benefits unless you need and your alternator can safely deliver more that 30 amps charge current.




-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: StephenH
Date Posted: 24 Jan 2023 at 9:39am
Initially, I was not thinking of disconnecting the Bargman's connector and running a wire from that to the DC to DC converter. I had already done the separate circuit when you mentioned that. My original goal was isolation of the DC circuit of the trailer from the Frontier for the reasons I have stated. Since it is done, I will stick with it until I change tow vehicles. Then I will likely check into doing it through the Bargman, although I would still want a battery isolation function. The isolation is the main reason I did it the way I did.

-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: offgrid
Date Posted: 24 Jan 2023 at 10:48am
Got it, thanks for the clarification. For sure, you need to isolate the Li battery from the risk of overcharge from the alternator circuit.

I'm thinking about what I want to do to connect the vehicle start circuit on my Chinook to the Li system Im installing in the coach. If anything.

Same set of issues except it will be hardwired rather than go through a connector.

Right now I'm inclined to keep things simple and have no connection. I'll have a big solar array plus a generator for backup so probably won't ever need to use alternator charging anyway. Saves buying a DCDC converter.



-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold


Posted By: StephenH
Date Posted: 24 Jan 2023 at 11:20am
It will be easier to wire a Renogy DC to DC charger into your Chinook as you will be able to easily connect to the ignition circuit to turn the charger on and off. I had to do something different. Since the isolation solenoid turns power on and off, I just had to detect when power was present, so I am not using the ignition circuit to do so, just tapping off the incoming power to do so.

-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS


Posted By: offgrid
Date Posted: 24 Jan 2023 at 12:17pm
There are already a couple of contactors under the hood that are connected into to the existing circuits between the house and start batteries, so I think one already activates when the ignition is turned on. All Id likely have to do is connect the input to the DCDC to that. I can buy a DCDC and do that later on if I find I need to.

The other contactor activates when I push an emergency start switch on the dash, allowing the house batt to be used in parallel to help start the engine. That is a nice feature that I'll lose, can't parallel a Li with a Pb battery. I might be able to partly replace it though by charging the start battery from my new inverter/charger, which I found out came with two separate 12v charge ports, one big 100 amp one for the house battery and a second low current trickle charge one for a second (usually starter on a boat engine) battery.

It's a 2kw Mastervolt inverter/charger and has generator/shore power support, meaning its inverter function will kick in to help run loads that might be too high for the generator or shore power by itself. Any excess power at low load will charge the battery if the gen/shore is on and if it's off the inverter will run the loads.

Seems like a pretty nice unit, got it on Walmart online for a very reasonable price. Haven't had a chance to run it yet though. You might want to check it out if youre considering getting an inverter at all. it'll charge the battery up to twice as fast as the WFCO.

According to the description in the Chinook manual there's also a low voltage disconnect in there somewhere, that I'll also have to find and remove as it wont be set up right for lithium.

-------------
1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold



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