2025 Rockwood 2109S LiFePO4 Battery

[TexasJackKin]

I have a 2025 Rockwood 2109S ordered, I've also ordered a LiFePO4 Battery with Bluetooth 280 AH battery, as our main use will be boon docking. My trailer will come with 2 X 200 watt solar panels. Do I need to do anything besides install the battery?

 

[TacomaJoe]

I'm thinking you're good to go. Check the converter and solar charge controller settings, a bonus is if you can set charging voltage. The Bluetooth will tell you everything you need to know about battery power.

 

[TexasJackKin]

I'm thinking you're good to go. Check the converter and solar charge controller settings, a bonus is if you can set charging voltage. The Bluetooth will tell you everything you need to know about battery power.

It should, but I can't get the bluetooth to work, I've tried the WattCycle, and the BMS Meta, and I'm not getting much help from WattCycle with either one..... VERY frustrating...

 

[TacomaJoe]

If the WattCycle app doesn't work on your WattCycle battery, I'd say you have a Bluetooth issue. I use the Overkill Solar app on mine, not sure if it will pair with WattCycle. When I start the app it scans to find all the batteries then let's me pick one to display.

The Bluetooth on your phone should see the BMS along with all the other stuff in range but if you can find something that looks like it is the battery at least you know your Bluetooth is active.

 

[TexasJackKin]

This is what it looked like, when I took the battery out of the box, it looked exactly the same as it was charging, and still looks exactly the same after charging (About 3 hours at 60 amp rate) The charger shut off, so I assume it's charged....

 

[TacomaJoe]

Looks like the app connected but didn't update any data. Does the "setting" button in the lower right do anything? Or how about the CHG or DSG buttons?

 

[TexasJackKin]

Looks like the app connected but didn't update any data. Does the "setting" button in the lower right do anything? Or how about the CHG or DSG buttons?

The buttons do nothing, except bring up a place for a password, and it's not 88888

 

[Aussieguy]

try the OVERKILL app

5 minutes to download and free
been around for years and all the bugs have been removed


Many of the generic apps have issues with login etc


If you can't get the discharge button green using a APP
try waking it by putting it onto a good battery or jumpstart cables to the truck

 

[Aussieguy]

400w of solar is a good start ... try it for a while and if need be upgrade it to more

Inverter ... if decide to add inverter for some 120v power
definitely more solar would be a plus

Much depends on HOW long you intend to camp off grid
a weekend with some TV is fine as is

a week... pushing it add a couple more panels (800w total) and a 50 amp mppt

 

[TacomaJoe]

The buttons do nothing, except bring up a place for a password, and it's not 88888

I think the app is connecting to the battery but is getting hung up on the password. WattCycle would need to get you some other code if the default doesn't work.

 

[fanrgs]

From experience, I would recommend 2w of solar for each 1A of Li battery. I have 500w of solar for 220A of LiFePO4 batteries and generally have no problem using the 2KW inverter for conv-micro, induction cooktop, hair dryer, and 120vac TV. Keep in mind that the inverter consumes about 10-15% of the power from converting 12vdc to 120vac. 150w of our solar panels are portable; very handy when snowbirding during low sun-angle winter months and camping under trees.

We also have a 12v fridge, 12v second TV, and 12v evaporative cooler (no refrigerated AC), so we can run everything when boondocking/dry camping. We also have a 3.6KW propane generator, but have only used it once while camping.

PS--we had a 2109S for 3 years. Towed it 27,000 miles, including a 7,000-mile trip to western Canada and Alaska.

 

[hamrover]

From experience, I would recommend 2w of solar for each 1A of Li battery. I have 500w of solar for 220A of LiFePO4 batteries and generally have no problem using the 2KW inverter for

I had never heard this simple recommendation, but I have to agree it is pretty spot on in my experience as well. My systems aligns perfectly with these numbers, and it has been nice to rarely even have to think about where my next kWh is coming from!

 

[Aussieguy]

size the battery so you got around 3 days of 12v power available
since I don't use an inverter.............. 200ah does the trick nicely without breaking the bank

solar only needs to be sized to be able to replace the power you used
Typically I use 20% of my battery overnight .... 40ah or 480wh

If you get 5 hours good charging from solar a day ............... 40ah / 5hrs = 8amps

so you need a solar system ' that will do around 12-15 amps constantly for 5 hours
(extra power need to allow for for fridge etc. to be powered..... while the solar is re-charging battery)

12amps @ 14v = 200w ....because panels are FLAT on the roof they only perform at around 50%
so you need a minimum of 400w of panels

if you use 40% of battery overnight you need double the solar panels
Using battery as a guide to how many panels is only good if you use 100% of the battery
do the math instead work out an estimate of battery usage... and then do the math

be prepared for those days you just don't get good solar production...
moochdock or small generator or pay for a campground for a few days


-------------------------------------------------------------
the MORE panels you can get, the better off you are.
my system of 740w of panels is oversize for my charging needs as it is completed most days around 2-3pm
No reason I should not be able to add a medium sized (1500-2000w) Inverter...
if I ever decided I just have to have K cups or watch a 120v 65inch television for a few hours.

ONCE YOU DECIDE ON PANELS.... get a controller to suit them!

please note.... figures are rounded up to common sizes used in solar components

 

[JetMonkey]

Interesting stuff. I pick up my first camper this weekend and it happens to be a 2025 Rockwood 2109S. As delivered it will have 400W of solar on the roof along with an 1800W inverter. Unfortunately it will deliver with an old school deep cycle battery.

I've been reading just a bit about the LiFePO4 batteries. Not sure how much boondocking the wife and I will do but we do plan to do some on occasion. May have to look more into updating my setup at some point.

 

[TexasJackKin]

Interesting stuff. I pick up my first camper this weekend and it happens to be a 2025 Rockwood 2109S. As delivered it will have 400W of solar on the roof along with an 1800W inverter. Unfortunately it will deliver with an old school deep cycle battery.

I've been reading just a bit about the LiFePO4 batteries. Not sure how much boondocking the wife and I will do but we do plan to do some on occasion. May have to look more into updating my setup at some point.

I'll have the same set up in a couple of weeks, hopefully.... if I can trust the dealer's time frame. We are mostly boon Dockers, moving up from 55 years of tent camping. I've already bought a 280 amp hour LiFePO4 battery, and promised the cheap FLA/AGM battery that will come with the new trailer to a friend.

When you pick yours up, let us know how you like it!

 

[Campworthy]

I purchased a 2024 2109s last September, so I'm still in my learning curve! I mostly weekend camp with hook ups but once a year boondock for 5 nights. I previously owned a HW pop up, fridge on propane, 100w solar kept our 1 group 24 battery charged to run everything else and it was no problem on our 5 night trip.

I am a bit concerned that we won't make it 24 hours with our now 12v fridge. I have 200w solar on the roof, 100w solar on the side and 2 crappy group 24 batteries.

If I change out my batteries to a LiFePo4 200AH minimum, is it an easy change out? I'm clueless when it comes to this sort of stuff, can anyone simplify this for me please?

 

[TitanMike]

I purchased a 2024 2109s last September, so I'm still in my learning curve! I mostly weekend camp with hook ups but once a year boondock for 5 nights. I previously owned a HW pop up, fridge on propane, 100w solar kept our 1 group 24 battery charged to run everything else and it was no problem on our 5 night trip.

I am a bit concerned that we won't make it 24 hours with our now 12v fridge. I have 200w solar on the roof, 100w solar on the side and 2 crappy group 24 batteries.

If I change out my batteries to a LiFePo4 200AH minimum, is it an easy change out? I'm clueless when it comes to this sort of stuff, can anyone simplify this for me please?

Since you have a late model trailer changing to LiFePO4 batteries should be easy.
Merely adjust the charge settings on converter if necessary, may be be auto-detect.
Purchase the largest capacity battery that fits battery rack.
If you never camp during freezing weather any LiFePO4 battery that fits should be fine. If planning on cold weather camping either mount batteries in a heated space or purchase a battery that includes self-heating.
Might also consider a small (2500 watt or so) inverter generator. Quiet and light weight as well as really nice to have when boondocking and Sun is "vacationing elsewhere."

Then just enjoy.

 

[jimmoore13]

TacomaJoe covered the essentials for charging. Two other things come to mind.

The selling dealer owes you a marine battery. If, because you brought your own, the dealer didn't provide a battery and/or equivalent value in discount or service installing your lithium and making the switches to the higher voltage output on both the solar charge controller and the converter/charger (if needed), the dealer owes you about $100 for the battery.

Echoing TitanMike, all the solar and battery in the world won't eliminate the need for a generator.

1. You need something to run the microwave, coffee maker, and other small appliances. Don't think you can add a big inverter (minimum 2000 watts) and you can get away without a genny to feed those appliances. For illustration, if you pull 2000 watts out of your battery, you're sucking 166 amps. (Watts are power.) Big loads on inverters inhale batteries. You don't have enough battery or solar to do that very long.
2. You, no doubt, have a 12 volt compressor fridge, and that will eat a minimum of 35 amp hours (AH) per day...more like 80 or so on a hot day when you're dumping cold air onto the floor and pumping in warm air (opening and closing the door) often. Your 280 AH battery allows you to use about 80%, so your real battery size is 224. Still a robust battery, but it's not an infinite well.
3. I boondock exclusively, and I have 400 watts of solar. In sunny Colorado at altitude (less filtering atmosphere), in June (best solar gain), 400 watts of solar can produce roughly 5 AH/per hour/100 watts of solar panels. And it will produce that for roughly 3 hours...say 11:00 AM (daylight time) to 2 PM...or so. That adds up to 60 AH total during peak sun. For the whole rest of the day, you might double that to a grand total of 120 AH of charging. You're not likely to see that kind of solar charging performance in spring or fall. If your fridge is eating 80 AH of that all by its lonesome, that solar gain leaves your solar gain at roughly the equivalent of one marine battery's worth to run the furnace overnight, the awning in and out, lights, water pump, stereo, TV?, and so on, PLUS the relentless 3 AH/day for parasitic loads. So, even on the best solar days, you're likely to be deficit spending out of your battery...not a lot, but definitely some.
   NOW THROW IN A RAINY DAY...or three. The genny will save your bacon.
   And let's not forget about shade. Solar gain on your prized campsite might be reduced considerably by shade. So there's that.
4. And what about air conditioning? You simply can't do that with solar and batteries scaled to your rig. If you think you'll need the AC, scale your genny accordingly. With a soft start and good luck, a 2KW inverter genny might run your AC...especially a 13,500 BTU model. Less likely with a 15,000 BTU AC. And there will be precious little power to spare when the AC is on. If you might need AC, you're better off with a more robust generator - 3500 watts to 4500 watts. And to handle that beast you need to be on the strong side, because "wet" with fuel and oil, they'll weigh in around 110 pounds. Some folks will install a receiver hitch on the back of their rig and add a carrier for a motorized wheelchair (with ramp) or similar to haul that beast. Others will just toss it into their truck bed.

TMI? Perhaps. You asked what else you might need. I don't know your battery, so I have no comment on the bluetooth software. If all else fails, your solar charge controller will tell you a lot, and a Victron Shunt will prove helpful, too. But that's if your bluetooth continues to give you problems.

 

[Larry-NC]

This is what it looked like, when I took the battery out of the box, it looked exactly the same as it was charging, and still looks exactly the same after charging (About 3 hours at 60 amp rate) The charger shut off, so I assume it's charged....

View attachment 980358

Guessing that the shunt was not connected properly when the LiFePO₄ battery was installed, so the app cannot detect state of charge.

 

[fanrgs]

We ran our 12v fridge + any parasitic drains on only 350w of solar and 220Ah of LiFePO4 for 6 days, including 2 overcast days, as a test. I placed one gallon jug of room-temp. water in the fridge and another one in the freezer. By the next day the freezer jug was frozen solid and the fridge jug was cold. According to my infrared thermometer, neither jug changed temp. for the remainder of the 6 days. On the 7th day, we loaded the fridge and freezer and left on a month-long trip. I don't know how much longer we could have continued the test, but it convinced me that the system had plenty of capacity for running the 12v fridge.