simple minded lifepo4 set up.

[L0veless]

We have a 2016 Monty Love it, I currently carry 2 2,000 watt generators. My battery is dying and looking to replace with Lifepo4 battery 280ah along with 3000 watt inverter. We rarely use the generators mostly one night stops from point a to b.
MY thinking is when we stop, I can run the generators to use air conditioning and power the coach then at night shut them down, plug generator cord in the 3,000 watt inverter,keep it plugged into the coach. trip the breaker so coach converter does not circle back to the battery. I should be good for the night.
I know my power center converter will not fully charge the lifepo4 battery. my truck should charge as we are going down the road and then on shore power I would top off battery with a proper charger.
We most likely be changing rigs in a year or 2 so I don't really want to hard wire or change things out, when we do move on I can easily replace battery and take the inverter with me. what am I missing in this set up?

[kowbra]

Originally Posted by L0veless

We have a 2016 Monty Love it, I currently carry 2 2,000 watt generators. My battery is dying and looking to replace with Lifepo4 battery 280ah along with 3000 watt inverter. We rarely use the generators mostly one night stops from point a to b.
MY thinking is when we stop, I can run the generators to use air conditioning and power the coach then at night shut them down, plug generator cord in the 3,000 watt inverter,keep it plugged into the coach. trip the breaker so coach converter does not circle back to the battery. I should be good for the night.
I know my power center converter will not fully charge the lifepo4 battery. my truck should charge as we are going down the road and then on shore power I would top off battery with a proper charger.
We most likely be changing rigs in a year or 2 so I don't really want to hard wire or change things out, when we do move on I can easily replace battery and take the inverter with me. what am I missing in this set up?

I think I understand and think it will work.
The key is that you will be able to apply charging at the higher voltages needed for lithium, but it sounds like you will do that with a proper charger with a lithium profile, correct?
edit: and to make sure, you will use the charger on shore power directly to the battery and bypass your converter?

The truck will charge without limit from the alternator, but with very little amps due to the wire size, so it may not be enough on its own.

I'm curious why you need that much lithium battery especially with the amount of generator you plan to use; what all do you run off the battery alone?

Glad you are wandering with your 38 year old best friend but hope they weren't the one that gave you your username

Brad

[L0veless]

Cost difference between 280- ah vs 100 hr was very little. my plan is after rig cools down turn off geny and run off battery. I wont be drawing much Tv few lights is all.refer is on gas. When I plug in to shore power and use

lifepo4 charger to top off should I disconnect the coach converter?



My handle is basically my Last name Loveless.

[Creeker]

Be sure to turn off electric water heater and second A/C along with converter when plugging in to the inverter.

You should be able to run one A/C for a couple hours with that battery and 3000 watt inverter. Microwave and hair dryer as well. Just not all at the same time.

Its easy to forget to turn off the converter. On our previous 5er I installed a 30Amp NC contactor to automatically turn off/on the converter circuit when inverter is turned on/off.

[jetskier]

Why not consider get a 3000W inverter/charger?? They can be programmed for Lithium battery charge profiles. That way you don't have to remember to turn it off on the converter. It's automatic. You'd have to do some creative wiring to isolate circuits from the inverter, but it can be done.

[L0veless]

if I trip the 80 amp breaker going from the battery to the coach shouldn't that isolate the battery from the coach? if so why would I have to turn off the converter? I don't know, this is why I am asking. yes to turning off a/c, water heater, all that stuff just watch a little TV run fridge on gas.

I do not want to hard wire anything, if we do change coaches I can easily take this set up with me and just drop in a wet battery like I have now. As far as the charger goes I have one and use it for another battery bank (lifepo4) in my golf cart.



I just want to make sure I don't fry anything. electricity is not my thing.

[66 Galaxie]

If you go with a 3kw inverter/charger you can remove the converter(turn off breaker) and charge any battery type. Plus it's a way better charge profile than what the converter will put out. If your rig has a transfer switch you can wire the inverter into through the shore relay and move shore to the generator relay so the primary source is shore with the inverter only running when shore goes away.

[L0veless]

No transfer switch, this is our first coach. knowing what I know now, things would be set up a little differently. but hey it is what it is. I do love everything about her.

You battery gurus out there, does this add up just asking. 280 AH run down to 20% should give me aprox. 220 AH ( it has a BMS for protection on run down). So a 20 amp draw should last about10hrs? I know my inverter will use some energy. Does this add up or am I missing something here also.
Everyone thank you for your input and direction.

[Creeker]

If you isolate the coach from the battery nothing that runs off 12V will work inside the camper. That includes your lights, water pump, furnace, fridge and water heater. The latter three require 12V to operate their control boards/systems even though they are turned on gas mode.

Two 6V lead acid batteries and a 400 to 800 watt inverter will easily run everything you describe above at a fraction of the cost. I did exactly that for 10 years in our previous camper. Used our Honda Genny for any big load.

[Daryles]

Interesting idea. Off hand I don't see why it would not work (provided you turned off the converter circuit breaker to prevent loop back).
You will only have a couple of hours of air conditioning use before the battery would be depleted. Power management would be key.
You would also want to install a "Soft Start" on your air conditioner to reduce the start up surge current.
You may want to look at a DC to DC charger to maximize the charging circuit from your truck to the RV while towing or just to top off the batteries without running the generator.
I'm looking at the Renogy 60A DC to DC charger. I have 400W solar, 30A MPPT and 552Ah lithium batteries. We will need to install a soft start on the AC before we will be able to use it.
Another factor is your inverter output. I have a 2000w (4000W surge) inverter with three 120vac receptacles. From what I understand, the 2000w/4000w are divided between them. I'll have to experiment with the AC when the time comes. I may need to tie all 3 outputs together to get enough to run the AC.

[L0veless]

my inverter is 3000/6000 I just assumed I could plug my 30 amp adapter into it and go. that has me concerned have to look closer at that issue.
Thank you