Don't understand the Li3 System

[Jhv2]

Originally Posted by booster

I don't understand the 30 amp circuit being needed

The 30 amp recommendation is overstated. The concern is that if on 15 amp circuit you are using some of that power there may be a reduced output of the charger during float stage so that it does not have enough voltage for enough time.

It does not need all 30 amps. If hooked to 15 amps and nothing else is using inverter/charger power it will do ok.

Secondly this balancing is only needed if you have consecutively run up and down your batteries over a period of time. The Lithionics app can show you the exact levels of each cell so you can check if you are even approaching an unbalanced state, and then take measures as needed.

For simplest sake for those who don’t want to understand why, just hook to 30 amp every two weeks. -- therefore the oft quoted recomendation.

[Dogman]

Originally Posted by Davydd

I don't have an L!3 battery system but I would think if the inverter is on, you are charging, cooling the inverter and reading a panel there is a draw. Unplug and see if you are drawing power. I imagine you can't. If you can, where is the power coming from? The battery?

Morning Davidd, You sir always ask some great questions and I hope I can address you question completely. The newer Coachmen RV with LI3 can last much longer than 10-hours of stand-alone time before a recharge of the battery packs: Here is an insert form the Flyer which is an OPTION,

Li3 Lithium Battery – 630 amp-hour lithium battery with internal heater, Bluetooth battery management system and remote LCD display, second under hood alternator with multi-stage voltage regulator, Xantrex XC Pro 3,000W inverter/ charger with Bluetooth XC Remote, Xantrex Echo-charge (charges chassis battery while plugged into shore power). Onan Generator not included with Li3 Lithium Battery option.
Extra 630AH Lithionics Lithium Battery /w Internal Heater (1260AH Total w/ Li3 Lithium Option) (Must Have Optional Li3 Lithium Battery System)

Under the hood it's a look-like alternator, (replacing the fuel generator, but only used when you start the engine) which can fully charge the 630Ah in 2-1/2 hours and once fully charged should last for 10-hours. I also have three Solar Panels on top which are 330-Watts. These are my two go to when on the road. When charging Both my House and chasses batteries are kept charged using 30AMP or plugged into a standard 120 outlet. Now the A/C on top of the VAN is a 12-volt, 20,000 BYU.

We have to drive once in 30-days, and fully recharge our 630amp Hour batteries when setting with Solars and all power off about 30 days when it drops from 100% State of Charge for me between 39% to 32% before I will drive and charge. Here is a link with more detail I hope is better help the me: https://coachmenrv.com/brochures/202...ningmanual.pdf

[booster]

Originally Posted by Dogman

Morning Davidd, You sir always ask some great questions and I hope I can address you question completely. The newer Coachmen RV with LI3 can last much longer than 10-hours of stand-alone time before a recharge of the battery packs: Here is an insert form the Flyer which is an OPTION,

Li3 Lithium Battery – 630 amp-hour lithium battery with internal heater, Bluetooth battery management system and remote LCD display, second under hood alternator with multi-stage voltage regulator, Xantrex XC Pro 3,000W inverter/ charger with Bluetooth XC Remote, Xantrex Echo-charge (charges chassis battery while plugged into shore power). Onan Generator not included with Li3 Lithium Battery option.
Extra 630AH Lithionics Lithium Battery /w Internal Heater (1260AH Total w/ Li3 Lithium Option) (Must Have Optional Li3 Lithium Battery System)

Under the hood it's a look-like alternator, (replacing the fuel generator, but only used when you start the engine) which can fully charge the 630Ah in 2-1/2 hours and once fully charged should last for 10-hours. I also have three Solar Panels on top which are 330-Watts. These are my two go to when on the road. When charging Both my House and chasses batteries are kept charged using 30AMP or plugged into a standard 120 outlet. Now the A/C on top of the VAN is a 12-volt, 20,000 BYU.

We have to drive once in 30-days, and fully recharge our 630amp Hour batteries when setting with Solars and all power off about 30 days when it drops from 100% State of Charge for me between 39% to 32% before I will drive and charge. Here is a link with more detail I hope is better help the me: https://coachmenrv.com/brochures/202...ningmanual.pdf

I wonder about the 2.5 hours to recharge 630ah of battery. If it would be the full 630ah you need to average 252 amps of charge continuously, and none of the underhood 12v alternators I have seen results from, except the monster Delco unit ARV uses, will average that high. Most I have seen data from were in the 160-170 amp average.


How much of that 630ah are you recharging in 2.5 hours. Is it a full 12v system and not charging at 24v or more?

[dmb496]

I interpreted Dogman's charging event to typically begin somewhere between a SOC of 32% to 39%, and continue until a 100% SOC is reached for his 630 ah of coach battery. 2.5 hours of driving would achieve 100% SOC at 170+ ah.

FWIW, I have the same Nations alternator that Dogman has. It is rated at 280 amps. During highway driving I typically see an initial output of 215 amps, and then a slow taper downward to 195 amps, continuously, until nearly 100% SOC is achieved. The last 3%-4% rate of charge continues to ramp downward.

At idle the Nations alternator puts out 155-165 amps.

[dmb496]

Originally Posted by booster

I don't understand the 30 amp circuit being needed as it appears you would have a 3000 watt Xantrex inverter/charger which is shown on the Xntrex site as having a 100amp DC charger. They do also so it is a 3000/150 so some spec may be wrong. A 100 amp charger usually runs at just under 15 amps of AC and some more on starting surge but that usually doesn't require bigger service. Our 100 amp DC Magnum charger can run fine on a 15 amp circuit. If you really need 30 amps to charge the batteries properly how are you going to camp and charge on shore power? You would have no power left for anything else like cooking, etc unless it load sheds which would again, if they are correct, affect battery balance.


It all makes absolutely no sense to me.

My system uses a Xantrex XC Pro 3000 watt inverter/charger. It will charge the battery perfectly when connected to a 120 volt 15 amp duplex outlet IF the software for the incoming amperage setting in the Xantrex is changed to 15 amps input.

[booster]

Originally Posted by dmb496

My system uses a Xantrex XC Pro 3000 watt inverter/charger. It will charge the battery perfectly when connected to a 120 volt 15 amp duplex outlet IF the software for the incoming amperage setting in the Xantrex is changed to 15 amps input.

It is also possible that the OP is getting too large a voltage drop on the 15 amp circuit and tripping the low AC input fault.


It is easy to have 50-100' of 14ga wire from the house breaker panel to the outlet, usually with multiple connections along the way. Add in another 25-50' extension cord and a few more connections and you would probably be toast on voltage drop.



It probably would be advisable to check the voltage in the van with the charger running, if possible, or check the charging system for AC fault codes.

[weather command]

Newbie here> Thank you in advance for helping me with following questions.
My class b rv has a LifePO4 600 AMP Hour Li3 battery ( and 3000 w pure sine wave inverter ( xantrex freedom sw 3012). I am counting on 4-5 hours of continuous ac throughout the night ( have not tested system as of yet ) while boondocking. I am about to embark on a 10000 mile trip and want to make certain my dog and I are comfortable if we run into HOT nights which is almost certain. Thinking about buying a portable predator 3500 watt inverter generator to help get me thru nights, if needed. Will this do the job? Also, I am assuming I would turn off the xantrex coach inverter before plugging into portable inverter generator? Ty so much for your help!

[JoeM]

RV dealers are notorious for not explaining things. First do not charge your RV at home unless you have a 30 Amp 120 volt circuit. 15 Amp can cause the battery to become unbalanced. I wired a specific 30 Amp plug into my garage so I can charge at home. I was told that by the folks at Coachmen during one of their RV rallies. Your second alternator should fully charge the batteries. Make sure the inverter is on. You should see a positive number in the on the panel. Drive the van around and see if you come up to ~600 Amps or around 8300 watt/hrs, depending on how your display is set up. Solar does very little. Most vans only have about 200 watts of solar on the roof. On my Coachmen Nova Li3 I can run maybe the refrigerator and the fan on a sunny day and keep the battery/charge ratio at about 0 or a few watts. On a recent trip to Charleston, SC, I was able to run the air conditioner for 4 hours, while using about half of the battery capacity.

If after running the van and you are still not charging to full, check back with your dealer.

[avanti]

Originally Posted by JoeM

First do not charge your RV at home unless you have a 30 Amp 120 volt circuit. 15 Amp can cause the battery to become unbalanced.

Well, a 15A 120VAC circuit can provide 1800 watts (which is what really matters, not the amps). I don't quite see how the above claim can be true. Can you elaborate?

[booster]

Originally Posted by avanti

Well, a 15A 120VAC circuit can provide 1800 watts (which is what really matters, not the amps). I don't quite see how the above claim can be true. Can you elaborate?

I thought the same thing as it makes no sense, at least from what I have seen in our lithium system and testing. 1800 watts is very similar to what the net charge rate of the second alternator would be.



I also think the post meant 600ah as to what to watch for not 600 amps which is virtually impossible to reach with normal systems like this.

[weather command]

Originally Posted by JoeM

RV dealers are notorious for not explaining things. First do not charge your RV at home unless you have a 30 Amp 120 volt circuit. 15 Amp can cause the battery to become unbalanced. I wired a specific 30 Amp plug into my garage so I can charge at home. I was told that by the folks at Coachmen during one of their RV rallies. Your second alternator should fully charge the batteries. Make sure the inverter is on. You should see a positive number in the on the panel. Drive the van around and see if you come up to ~600 Amps or around 8300 watt/hrs, depending on how your display is set up. Solar does very little. Most vans only have about 200 watts of solar on the roof. On my Coachmen Nova Li3 I can run maybe the refrigerator and the fan on a sunny day and keep the battery/charge ratio at about 0 or a few watts. On a recent trip to Charleston, SC, I was able to run the air conditioner for 4 hours, while using about half of the battery capacity.

If after running the van and you are still not charging to full, check back with your dealer.

I'm not sure I am explaining myself very well? Sorry for that. I am concerned my battery system will NOT last thru the night with REALLY hot weather this summer and am considering buying a portable inverter/generator to supplement my battery concerns. I have narrowed down my choice to the Westinghouse IGEN4500DF Watt Dual Fuel Portable Inverter Generator which I am certain will be enough to power the ac, fridge, water heater and lights if need be. My question is > If I need to change over to the portable inverter/generator, should i turn off the xantrex inverter BEFORE I plug the RV into my portable inverter/generator? TY for your answers.

[JoeM]

I was told last year at the Coachmen rally that some people were charging when visiting relatives on a 15 Amp house circuit. This was causing the individual cells in the Lithionics battery to become unbalanced. I don't know how many cycles of charge and discharge caused this issue. The battery BMS system is expecting a certain level of current to maintain consistency across all the cells that make up the battery. I don't know the exact cause of this, but I was always told to charge off of the second alternator or use a 30 Amp circuit. I installed a 30 Amp circuit in my garage for that very reason

[avanti]

Originally Posted by JoeM

I was told last year at the Coachmen rally that some people were charging when visiting relatives on a 15 Amp house circuit. This was causing the individual cells in the Lithionics battery to become unbalanced. I don't know how many cycles of charge and discharge caused this issue. The battery BMS system is expecting a certain level of current to maintain consistency across all the cells that make up the battery. I don't know the exact cause of this, but I was always told to charge off of the second alternator or use a 30 Amp circuit. I installed a 30 Amp circuit in my garage for that very reason

I understand that you are just passing on what you have been told, and I most certainly don't mean this as a personal criticism. However, as far as I can see, this honestly makes no engineering sense. It is just not how electricity works. As @booster said, a 15A circuit provides approximately as much power as your second alternator. If one caused problems, the other one would as well. Moreover, if the charging system was drawing more than 15 amps (which is what I assume you mean by "expecting"), your circuit breaker would pop.

Now, I don't know everything, and maybe I am missing something. But, with all respect (and I mean that), absent an actual explanation of the engineering behind this theory, I think it needs to be filed under "hearsay".

P.S. -- Grasping at straws here, but I suppose that one possible mechanism that *might* make a difference may be the use of long extension cords with insufficient ampacity, which would cause voltage drop. However, I don't see how a 30A outlet would help if that is the problem.

[booster]

Yep, and I just don't see what any of it has to do with battery balancing as you can have a balancer that puts out 5 amps balancing an 800ah bank successfully.


Manufacturers and dealers, many who haven't a clue about how it all works, will nearly always try to pin any problem that shows up on somebody other than themselves, and that is what this sounds like to me.


It would be interesting to have the "expert" giving this information to explain the actual how and why or it and also explain just how the LI3 controls charging and balancing in the system. If you ask for that information you will probably get a blank stare, though, or more blame shifting from them.

[Glamper Jan]

You have propane sensors, C 02 sensors, All kind of sensors that have a phantom draw. Four amps is nothing. Batteries only charge to eighty percent anyways so you are fine.