Wiring from LV5048 to breaker box for 50amp service outlet

schmism said:

If you wired the generator receptacle directly to the grid input on the MPP, the unit (if configured correctly) will use the generator power to charge the batteries. You need to ensure that the generator power does not "mix" with the AC power output of the inverter. This can be accomplished a number of ways.

You'll want to ensure that your grid-battery-charge-current setting does not exceed the recommended charge current for the BB bats.

You'll also need to pay special attention to the overvolt setting and undervolt setting on the MPP and ensure they are within the range of the BMS on the BB. (if the MPP is set to overcharge/overdischarge the BB, the batts will self-disconnect and, as the MPP unit is powered off the batteries, the system will shut down)

I also feel compelled to point out that your 24v 50ah BB are only rated for 60amps continuous discharge, were as the MPP has the capability to pull 200a+ off the battery. (you either have to much inverter for the batts, or not enough batts for the inverter)

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Thanks for the reply. I don't have enough battery for the inverter, at this point. I will add on down the line. I don't really need the power right now, and BBs are kinda expensive!

In regards to wire size from the inverter to the batteries, I opened up one of the batteries today and noticed that it used 6awg cable inside also. Is this going to be an issue? The breaker on each pack is 63 amps.

jimjones26 said:

In regards to wire size from the inverter to the batteries, I opened up one of the batteries today and noticed that it used 6awg cable inside also. Is this going to be an issue? The breaker on each pack is 63 amps.

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@jimjones26 How have you made out? I am planning on getting the LV5048 as well and have been following this thread.

I am still working on this, I have had other projects I have been tying to get done before the snow comes and does not leave.

I have a 50AMP inlet that will take the power from my generator and bring it to the inverter. Between that 50AMP inlet and my inverter will sit a cutoff switch with a 40AMP breaker in it. I have a 50Amp outlet box that will be installed to the outside of my trailer and will accept the 50AMP RV plug from the RV. Between the AC out on the inverter and the RV plug sits a load center with a 60 AMP main breaker, a 50AMP service breaker that provides service to the 50AMP RV outlet, and a 20AMP service breaker that will provide an outlet inside my trailer to plug in some sort of heater for those cold nights.

All of the wiring for AC input and Output will be 6AWG. I rebuilt my battery cables to 1/0AWG, and have a DC cut off switch and a 250AMP fuse between the battery packs and the inverter.

Everything in the trailer will be properly grounded, as well as the trailer itself.

I should have everything installed and ready to go by Christmas. I will report back then how it is all working. I do know I am going to need to add more battery capacity, which will probably happen in January.

I have the solar panels I need but we are still trying to decide where we want to build our house, which will dictate where I put the panels, so getting those up is on hold for now.

jimjones26 said:

I am still working on this, I have had other projects I have been tying to get done before the snow comes and does not leave.

I have a 50AMP inlet that will take the power from my generator and bring it to the inverter. Between that 50AMP inlet and my inverter will sit a cutoff switch with a 40AMP breaker in it. I have a 50Amp outlet box that will be installed to the outside of my trailer and will accept the 50AMP RV plug from the RV. Between the AC out on the inverter and the RV plug sits a load center with a 60 AMP main breaker, a 50AMP service breaker that provides service to the 50AMP RV outlet, and a 20AMP service breaker that will provide an outlet inside my trailer to plug in some sort of heater for those cold nights.

All of the wiring for AC input and Output will be 6AWG. I rebuilt my battery cables to 1/0AWG, and have a DC cut off switch and a 250AMP fuse between the battery packs and the inverter.

Everything in the trailer will be properly grounded, as well as the trailer itself.

I should have everything installed and ready to go by Christmas. I will report back then how it is all working. I do know I am going to need to add more battery capacity, which will probably happen in January.

I have the solar panels I need but we are still trying to decide where we want to build our house, which will dictate where I put the panels, so getting those up is on hold for now.

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Thanks for the update! Sounds like you've got your hands full and are doing a pretty good job. Can't wait to hear back when you're finally done.

OK, I am working on getting this installed today, but I am having difficulty designing the grounding system. I understand from another thread I need to jump the neutral IN and neutral OUT on the LV5048. My question is, how to I go about grounding the rest of the system? I do have a ground rod and 6awg copper grounding wire ready, I'm just not sure how to go about grounding the whole system, including batteries. I'm also not sure if I need to bond the neutral and ground in my Load Panel.

jimjones26 said:

OK, I am working on getting this installed today, but I am having difficulty designing the grounding system. I understand from another thread I need to jump the neutral IN and neutral OUT on the LV5048. My question is, how to I go about grounding the rest of the system? I do have a ground rod and 6awg copper grounding wire ready, I'm just not sure how to go about grounding the whole system, including batteries. I'm also not sure if I need to bond the neutral and ground in my Load Panel.View attachment 30352

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It depends on how far away you are from the main grounding rod.
Code states that you do not ground sub panels to the main panel, they get their own ground.

The first 5 minutes are the most important part of the video.

Thanks for the video! That helped a lot. On to the next few problems. I have everything setup, with my ac output going to the rv input. Everything works as expected, except that the rv house batteries keep charging. I turned off the house battery disconnect but then I have no dc power.
Also, the inverter will not run the microwave. I am guessing it's a setting issue, as that would be pretty disappointing if the lv5048 can not handle a microwave.

jimjones26 said:

Thanks for the video! That helped a lot. On to the next few problems. I have everything setup, with my ac output going to the rv input. Everything works as expected, except that the rv house batteries keep charging. I turned off the house battery disconnect but then I have no dc power.
Also, the inverter will not run the microwave. I am guessing it's a setting issue, as that would be pretty disappointing if the lv5048 can not handle a microwave.

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Figured out the microwave issue, had to set the inverter to output 240 volts. Still searching for an option to bypass hoise batteries and still have dc power.

jimjones26 said:

Figured out the microwave issue, had to set the inverter to output 240 volts. Still searching for an option to bypass hoise batteries and still have dc power.

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Just a suggestion, don't use the 12V chassis battery for the backup of the A/C system.

It can be totally separate from the entire "shore" system, and totally separate from the 12/24/48V of the LV5048.

jasonhc73 said:

Just a suggestion, don't use the 12V chassis battery for the backup of the A/C system.

It can be totally separate from the entire "shore" system, and totally separate from the 12/24/48V of the LV5048.

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I'm not sure how to accomplish this. If I unplug the chassis batteries I no longer have dc power in the rv, which powers the heater blower motor and water pump. Last night I left the chassis batteries connected and the LV5048 charged them and then floated for the rest of the time I had the lv5048 on. Is this dangerous to do? Seems like it's the same thing as leaving golf cart batteries on a smart charger all the time.

To be clear, I have separate batteries hooked into the LV5048 battery input.

Something is not drawn on your schematic.

Is the LV5048 in the RV?

You can float indefinitely. Float voltage is normally a lower voltage than the bulk charging, or at least it should be. With the LV5048 you can set it to be whatever you want, and totally dork it up pretty easy! ??

If you have a trickle charger for the 12v chassis system plugged into the A/C panel from the LV5048, that would certainly work also. The 48V battery running the LV5048 would be isolated from the 12v chassis system. The "trickle" charger doesn't care that it is getting 120V from the LV5048 or shore power, or a generator, it simply doesn't matter.

Yeah the whole lv5048 setup is installed in the rv, but completely isolated from the "house" rv system. I left the house system alone. The house system does have a 4 stage charger / inverter I installed last year to replace the old one that came with the rv. The house system has 4 6volt gold cart batteries, in series and parallel. Those batteries run the dc appliances. The LV5048 has a 50amp outlet that I use to plug into the rv, aka the shore power plug. When the LV5048 AC out breaker is flipped on, the RV then becomes plugged into shore power.

I think the way I have it setup is good. But now I have a new problem.

I have 4 24v lifepo4 batteries in series and parallel for the lv5048. However, tonight, 1 battery in each of the series died (I hope). They are were only reading 03.3 volts when checked with the multimeter. However, I just checked them again and they are reading 23.2 and 24.3 respectively.

I suspect the way I have them wired was causing the load to be pulled more heavily from 1 side of each series, causing them to drop below the BMS discharge limit. Not sure what to do about this.

Double post.

jimjones26 said:

Yeah the whole lv5048 setup is installed in the rv, but completely isolated from the "house" rv system. I left the house system alone. The house system does have a 4 stage charger / inverter I installed last year to replace the old one that came with the rv. The house system has 4 6volt gold cart batteries, in series and parallel. Those batteries run the dc appliances. The LV5048 has a 50amp outlet that I use to plug into the rv, aka the shore power plug. When the LV5048 AC out breaker is flipped on, the RV then becomes plugged into shore power.

I think the way I have it setup is good. But now I have a new problem.

I have 4 24v lifepo4 batteries in series and parallel for the lv5048. However, tonight, 1 battery in each of the series died (I hope). They are were only reading 03.3 volts when checked with the multimeter. However, I just checked them again and they are reading 23.2 and 24.3 respectively.

I suspect the way I have them wired was causing the load to be pulled more heavily from 1 side of each series, causing them to drop below the BMS discharge limit. Not sure what to do about this.

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Check what your LV5048 cutoff is. 23.2+24.3 = 47.5

Mine are almost never the same voltage pack to pack, don't worry about it. If you are seeing something way off, like 3.3 check the BMS/Balancer leads. I used to get that all the time and finally sorted it out as a loose wire from the balancer to the terminal on the battery.

As long as you have one battery directly connected to another, it doesn't matter what the internal voltage is on the cells, the system only is one battery. Even regular 12v lead-acid batteries are just 8 cells of 1.5v cells. Make sure you do NOT equalize your lithium from the LV5048. That is something entirely different and only for lead-acid.

The DC cutoff is the default 42 volts, so that's not it. I am thinking unequal batter cable lengths might be the issue?

My batteries have Anderson connectors, maybe I need to be running the two batteries in parallel to bus bars, and then single wires into the inverter? Right now I have double cables on both negative and positive connected to the inverter.

mEHHhh.
I have unequal from my dual LV5048's to a single "bussbar" then two cables that are equal to my "diagonal" battery bank setup. At these cable sizes and amps, I doubt it matters having equal lengths to the mm.

Ok, then the issue lies somewhere else. I switched the batteries around in series and the same thing happened. The two "bottom" batteries in each series pack shut off and now only read 3.3 volts with the multimeter. I'm tired and frustrated, I'll come back to this tomorrow.

Thanks for your help, I really appreciate it.

Ok all, I am nearing completion! I am working out the numbers I need for the charge controller on the LV5048.

As I have mentioned before, I have 4 24v lifepo4 batteries with a 92.8ah capacity each.

Wiring two batteries in series gives me a 48v 92.8ah pack. Two of these series packs in parallel give me a 48v 185.6ah pack.

Not enough ah to meet the recommended 200ah for this inverter, I know. The good news is we are barely running anything right now, just a dc water pump, dc lights and the dc heater fan.

I am having trouble understanding the charge settings I need for the LV5048 based on the pack I have.

Setting 05 needs to be USE, which then gives me access to settings 26, 27 and 29.

Setting 11: max utility charging current. Should it be .5c of the 92.8 ah, or .5c of 185.6ah?

Setting 26, bulk charging voltage. I have done some research but the proper voltage eludes me. I am using a generator to recharge everyday, so I would like the batteries to recharge as quickly as possible. I don't really need to get to 100% charge.

Setting 27, floating charging voltage. As I understand it lifepo4 does not need to be floated, but there is no option to turn off floating.

Setting 29: low dc cutoff voltage. Not sure what this should be.

Setting 32: bulk charging time. Again not really sure.

All battery equalization turned off, I believe this is correct.

Thanks in advance for pointing me in the right direction.

directly from BB website

Four BB10012 batteries mounted in series to form a nominally 48V system should be charged using a bulk and absorption voltage of 57.6V, and a float voltage below 54.4V.

2x 24v is the same as 4x 12v.

You should have your low voltage cuttoff above the LVOC of the BMS that runs the batts. This will alarm on the mpp before the BMS shuts down the battery which will cause a hard shutdown on the all-in-one as it wont run without a battery connected.

same goes for Hvoc

LFP doesnt have min charge rates like FLA. So you can charge at .1 C if you want. If your doing grid passthrough while on shore power you need to consider that if your passing 30 amps and have set the batteries to charge at 30 amps your going to pull more than your 40a input breaker shown.