Setting Up LiFePO4 Batteries and Fast Charging in a Rockwood 2509S for Boondocking

[mtlangst]

We have a 2021 2509s and am going to be doing boondocking so getting setup for that. I eventually want a solar setup but going to start with a dual fuel generator. I plan on getting s 12v 200ah lifepo battery to start. I hope to place it under the murphy bed. It will be a smart battery so I should be able to monitor the charge on the battery from my phone?? Is that correct? My main question is what is the easiest and allow for the fastest charge to the battery. I am looking at installing a litime 12v 80a charger. If i can plug my inverter generator straight into the charger is that all I need to do? I will expand the system, add solar etc… but to get me going initially will this work? I read also that you need ventilation while charging. Is it safe to charge batteries that are under the bed like that?

 

[escape pod 47]

The ne GeoPros have a "power package" option. With that option, the LiFePo4 batteries are installed in the pass through (under the bed).

 

[TacomaJoe]

You're good to go. No ventilation needed with LFP. Keep in mind that the 80A charger will only pump 80A with properly sized conductors.

 

[mtlangst]

You're good to go. No ventilation needed with LFP. Keep in mind that the 80A charger will only pump 80A with properly sized conductors.

Would the 60a be better. That was the recommended one for the battery. Figured is 60amp is good 80amp is better. I am a noob to all the battery/solar stuff.

 

[TacomaJoe]

There are two numbers to consider. First is the how much the charger can put out, second is how much the battery can take which is a function of the internal BMS.

 

[mtlangst]

Another option would be to install a converter that is suitable to a lifepo battery and then feed through the 30amp shore power connection from the inverter generator. This has the advantage of when connected to shore power camping it would top off batteries. Would that be a better option?

 

[reidfo]

Another option would be to install a converter that is suitable to a lifepo battery and then feed through the 30amp shore power connection from the inverter generator. This has the advantage of when connected to shore power camping it would top off batteries. Would that be a better option?

That is the route I chose, for that very reason. It's very convenient just to plug in and be done. I replaced my non-Lithium WF-8955PEC with a Progressive Dynamics converter. It wasn't quite the drop in replacement they claimed, but I managed to get it to fit in the same space.

 

[mtlangst]

How big is your battery? How long does it take to charge with generator through shore power connection? I have read that doing it through the camper system will take longer but it seems like a simpler way to do it.

 

[Aussieguy]

Rv wiring techniques leave a lot to be desired for fast lifepo4 charging

The wire size often is good but the lugs and grounding points are often totally inadequate to allow more than 20 amps

Make sure all negatives to frame are direct metal to metal contact and you'll see a vast improvement in charging amps
Costs nothing but a some time

 

[reidfo]

How big is your battery? How long does it take to charge with generator through shore power connection? I have read that doing it through the camper system will take longer but it seems like a simpler way to do it.

I have 2 100Ah batteries and 600W of solar, so with solar and the converter it charges the batteries pretty quickly. I haven't timed it, and my batteries are pretty much always topped off by 12-1pm even if not connected to shore power.

Charging times from your converter will vary. In large part it will be determined by the size of the wires from battery to converter and the distance in between. The larger the wires and/or the shorter they are the more charging amps you'll get.

If you absolutely need to get the batteries charged up super quick you can use a standalone 60 or 80A charger with large short cables run directly to the batteries (3ga or even 1/0). But I think you'll find the converter sufficient.

It can't hurt to put in the new lithium and see how your existing converter does with them. It will get to 80% or so real quick. The last 20% will be very slow on a non-lithium converter.

Even with the standard converter, lithium batteries charge MUCH faster than lead acid, and you'll have double or more usable capacity from them.

 

[Aussieguy]

If you on shore power....charging time is not a real problem

If you overnight... batteries will be at 100% when you wake up

Only time to care ... if you using generator and converter a lot

 

[mtlangst]

I don’t like generators. The inverter generator we have is 65db so not the loudest but don’t want to be that guy running a generator all evening. So the quickest method the better.

 

[mtlangst]

I have 2 100Ah batteries and 600W of solar, so with solar and the converter it charges the batteries pretty quickly. I haven't timed it, and my batteries are pretty much always topped off by 12-1pm even if not connected to shore power.

Charging times from your converter will vary. In large part it will be determined by the size of the wires from battery to converter and the distance in between. The larger the wires and/or the shorter they are the more charging amps you'll get.

If you absolutely need to get the batteries charged up super quick you can use a standalone 60 or 80A charger with large short cables run directly to the batteries (3ga or even 1/0). But I think you'll find the converter sufficient.

It can't hurt to put in the new lithium and see how your existing converter does with them. It will get to 80% or so real quick. The last 20% will be very slow on a non-lithium converter.

Even with the standard converter, lithium batteries charge MUCH faster than lead acid, and you'll have double or more usable capacity from them.

Think I will order the battery and do a driveway test to see how long the existing converting charges and if I am ok with it and use new converter money towards solar. Thanks for the info and suggestion.

 

[bikendan]

I don’t like generators. The inverter generator we have is 65db so not the loudest but don’t want to be that guy running a generator all evening. So the quickest method the better.

What INverter generator do you have, with a 65db noise rating?
My $300 Champion open-frame contractor-style generator had a 65db rating.
A good INverter generator should have a db rating no more than 60db.

 

[mtlangst]

The Champion 4500w dual fuel. It is rated at 64db

 

[TitanMike]

The Champion 4500w dual fuel. It is rated at 64db

However a Champion 2500w inverter generator, which provides MORE than enough power for charging (even enough for A/C with Soft Start) , is quiet enough to be un-noticable in adjacent campsites @53dba..

Mine cost ~$500 and only weighs 39#.

 

[Aussieguy]

A 60 amp converter .....only requires about 750 -800 watts of generator power ..... less when it is getting closer to full

So you can allow solar to do as much as possible then turn on generator around 5 pm... do some chores heating water etc and finish the battery top up

Many times it is not necessary to get battery charged to 100% every day...


My big 4500 champion sits in the garage
Neglected and all sad... just keeping it for hurricane insurance

 

[mtlangst]

Is there a need to get a new inverter or is the existing inverter in the 2509s sufficient?

 

[Aussieguy]

Inverter is to change 12 v. To 120
You size inverter based on what you want to power
Tv or hairdryer?

 

[mtlangst]

Inverter is to change 12 v. To 120
You size inverter based on what you want to power
Tv or hairdryer?

Gotcha. I won’t be glamping while solely on battery. Just maxxair fan, water pump, some lights, blower for heat in colder weather, awning, slide out. So assuming existing inverter is fine. I think the 2021 has a 1000w inverter but not sure on that.