[Richard]

TJ, I am not answering for Glenn. However my time to charge my lithium bank is controlled by the max output of the charger/inverter. My magnum caps out at 125 amps. If you were to boondock more I would pursue a way of getting more amps/hr into the bank such as a supplemental charge system.

[Gnawrocki1]

   

Battery capacity was picked by space.  I wanted the most I could put into existing battery compartments.  So yes, the capacity is 43KWh.  I figured it was like a garage, closet, welder....you can't have it too big.....

48V shrunk the battery cables which were already big.  This voltage kept the current down to a manageable level.  It does create other problems getting hardware like fuses, contractors solenoids, heaters, fans...but I was able to find them.  The switches were close so I used blue seas rated for 48v, not the actual max battery voltage.

I did build the battery myself.  It is my first inverter/battery/solar science project.  The picture I have is the battery form for the shelf that used to have 2 8D batteries in them that I did some testing on.

My inverters are set up for split phase 50A.

The charging for each inverter is 70A.  I don't know if I can charge at 140A, but I think I will be able to plus solar.  I do not plan to charge off of the 12V system while driving, I left that circuit alone other than disabling the merge and isolator circuits and wiring the existing inverter only to the engine batteries.

[TJ Clark]

Battery capacity was picked by space.  I wanted the most I could put into existing battery compartments.  So yes, the capacity is 43KWh.  I figured it was like a garage, closet, welder....you can't have it too big.....   

48V shrunk the battery cables which were already big.  This voltage kept the current down to a manageable level.  It does create other problems getting hardware like fuses, contractors solenoids, heaters, fans...but I was able to find them.  The switches were close so I used blue seas rated for 48v, not the actual max battery voltage.

I did build the battery myself.  It is my first inverter/battery/solar science project.  The picture I have is the battery form for the shelf that used to have 2 8D batteries in them that I did some testing on.

My inverters are set up for split phase 50A.

The charging for each inverter is 70A.  I don't know if I can charge at 140A, but I think I will be able to plus solar.  I do not plan to charge off of the 12V system while driving, I left that circuit alone other than disabling the merge and isolator circuits and wiring the existing inverter only to the engine batteries.

Thanks for the reply. So much to chew on. 

Totally agree with the welder analogy.

---

TJ, I am not answering for Glenn. However my time to charge my lithium bank is controlled by the max output of the charger/inverter. My magnum caps out at 125 amps. If you were to boondock more I would pursue a way of getting more amps/hr into the bank such as a supplemental charge system.

So a charger powered by the genset, but not on the inverter circuits. 

Thanks Richard.

[Jack Houpe]

You have 895 amp hour 140 amps is a smaller C charge rate (good for batteries) but you may have to use some cooling in that bay with the inverter chargers. That will certainly test them out.

If you're looking to bring that charge amps up you might consider a forklift charger but I would think with your inverter chargers along with the solar that you have on the roof it should work without an additional charger.

When you complete the system you could find tune your current draw.
We have eliminated all the major current draws in our coach to lessen the strain on the batteries and the system, old heat and air system gone replace with inverter mini splits, inverter refrigerator, disconnected the 220 element in the aquahot, we still have the 110 but that switch will only be on when we're plugged into shore power.

[Gnawrocki1]

Yesterday I had some time to start actual final battery installation!

All batteries have been top balanced to 3.64V and left hooked in parallel for about a week.

I got to where all batteries installed and switches with fuses wired up to the coach.

When I find some time actual battery wiring can be finalized.

[BusNit]

That looks awesome! Well done Glen! Well done!

[Jack Houpe]

Glenn that is PRO! Very well thought out.

[Gnawrocki1]

The cells/batteries are finally installed and wired up!  

I have been able to fire up the Batrium Watchmon BMS to insure that all of the cells are being monitored.  All cell voltages are within .03V after top balance and "parked unattached" for about 2 weeks.  

The Solar controller to charge the 48V batteries software has been updated to the higher voltage (I used this controller in the past for the 12V original batteries) with Victron standard LiFPO settings.  I will likely modify the voltage charging once the system is all commissioned to try to maximize battery life.

There are a few things of note:

First was something I never expected.  When I was loading up they system everything seemed fine.......until it wasn't at about 5500W.  I double and triple checked that all wiring connections were supreme.  As an example, on all of the cell terminals I modified a dowel to be able to sand the top of all of the connections, applied No-Ox ID special immediately, then assembled the buss bars to remove any Al oxide.  

However, I never expected that I did not install the wires into the main circuit breaker to the output of the inverter properly.  It turns out that when you install a panel box to the ceiling and loosen the contactor screw for a circuit breaker the clamping saddle falls as gravity is working against you.  This leaves a perfect spot for you shove the wire in above and outside the saddle.  I then tightened the saddle screw thinking it was clamping the wire....but no it was just hanging out where the saddle normally sits but it was making loose contact so that everything seemed fine.  Who would have guessed, so beware!

The second thing is that the shunt is not reporting to either Victron or Batrium the SoC of the battery.  Still needs further investigation.  I figured that I should have at least the Batrium software to report SoC as I made an easy extension cable, but the CANBUS connection from Batrium was special wiring as found on the internet.  I will need an education on this.

The third thing is that auto generator start function was something of a mystery as well.  For some reason the Victron Cerbo  system was indicating that I had a low voltage and was triggering the gen start solenoid.  Funny thing is I did not program it to do that.....yet, I only completed the wiring and was not trying to test that yet.  The Cerbo only has an on and off function to perform generator start.  On for generator start, off for generator stop.  This would not work on our generators as they need a momentary ground signal to start as well to stop.    I purchased a set of timed solenoids to provide that momentary signal when power is applied on the start side, and a momentary signal when power is turned off on the stop side.  

When the Victron solenoid commanded the generator to be on, the generator would run in a very funny mode that I have never heard before.  I think it has to do with the time I programmed into timed solenoids, but I am not sure.  I only let it run for a 10-20 seconds or so, but the generator was vibrating significantly and was much louder than normal.  Can the generator start backwards if the ground is made for too short of a time?  I am looking for direction here as this is not something that I want to forcibly repeat.  Help would be appreciated.


That is all I have to report on, pictures to follow.

[Jack Houpe]

Sounds like your making progress, programming the victron first time is a bit confusing as there are so many options so don't feel alone.

I do the the same on my terminals just as you did on my lithium install and used a flir camera to check the terminals found one connection that I failed to torque properly out of the 48 cells. It's a very useful tool if you have a spare $300.

Thanks for keeping us informed we are watching.

[Gnawrocki1]

I have been "playing" with the system trying to learn what I created......here are a few notes.

The auto generator start function is up and working. I had to increase the time of contact for the momentary start.  Currently the time I have selected is 1 second on after command.  I wasn't sure if the auto gen stop is going to be nice to the generator because it will shut down under whatever load is going on.  In the past, I have always unloaded the generator electrical load before turning off.  Is this a problem shutting the generator down while under kind of high load?

I have started the generator and loaded the system up to 12KW with a/c, electric car charging through buddy plug, refrigerator, battery charging all at the same time.  With no issues to report.....at that time.  If I sustain a high load for a long time charging my car at 35A (220V), I do eventually overheat the inverters when the doors are closed and it is 110F outside getting an alarm.  I do plan on adding a few fans in the compartment, but I have not added any venting to the compartment to add cooling.  

I am looking for ideas on how to add venting to the compartment.  I think my compartment is fairly tight (left and right, 4 and 5 is 1 big open type volume), but I think I might be able to add a computer type flat fans to the ceiling of L5 or R4 to move air into the space between the ceiling of the basement and the floor of the coach.  Does anyone know if there are any air exits from that space?  All I can remember is it seemed cavernous.  Help is appreciated.

Thanks
Glen