Been studying adding a LifePo4 (LFP) Battery Bank to our Host Mamoth Camper for a while. Wanted to get 400 ah at 12V to fit in the camper battery box which holds two 6V golf cart batteries. After studying the off the shelf drop in batteries, like Battery Born, I could not find any that would fit in my battery box and give me 400 ah so had to go to prismatic type LifePo4 cells.
Below is the battery box after installing the sixteen 100 Ah prismatic cells. Note the two BMS connectors dangling down on the right along with the on/off switch below them. These where left in an accessible place for setup/control of the BMS controlling the system.
The following pages will describe the design process I went through as I figured out what and how to implement the battery install.
Table of Contents
2.1. Series and Parallel Cells
2.2. State Of charge (SOC) and Charge Rates
2.3. LFP Discharge/Charge Curve
2.3.1. Things to Note From Charge/Discharge Voltage Curve
4.3. Why I Chose Top Balance Verses Bottom
5. Host Camper House Bank LFP Design Elements
5.2 Electric Car Parts Company ECPC-100Ah-Fortune Aluminum Encased Battery
6. Good links for LFP Information
7.3. Victron Multiplus(MP) Set Up
7.4. Victron MPPT 50/100 Set Up
7.5. Victron Color Control CCGX Set Up
1. Introduction
We just finished a 400 ah(amp hour) 12V battery bank install for our Host Slide In Truck Camper. We are planning in putting a system in our boat also with lessons learned from this install. The installation for marine systems is more stringent than RV since there is nothing more deadly on a boat than fire, you can usually get out of an RV if required.
There is a lot of information on the web about Lithium Iron Posphate (LifePo4 or LFP) battery installations. My purpose with this write up is to provide information that is not easily figured out from information on the web. The main factors that have influenced the design are as follows.
- Fire safety, all Lion Cells have flammable electrolyte that can ignite under the right conditions even LFP.
- Battery protection and longevity
- Battery monitoring at the cell level
2. Basic concepts
2.1. Series and Parallel Cells
LFP cells have a fixed voltage per cell of around 3.2V so to make up a 12V battery bank you need four in series. You then add batteries in parallel to increase the amp hours. The nomenclature used to describe the battery bank configuration is given as nPmS where n is number of cells in parallel and m number of cells in series. For example the camper is made up of 100 ah prismatic cells in a 4P4S = Four Parallel Cells/ Four Series Cells configuration for 12V at 400 ah.
Figure 1
When you buy prismatic cells most suppliers will provide metal bus bars that are simply a strip of metal with two holes you slip over the +/- terminals on the batteries to tie them together in the required nPmS configuration. For example here are my 16 batteries tied in parallel 16P1S when I balanced them. All the + terminal are connected with bus bars, all the – terminals are connected to put all cells in parrallel for 1600 Ah at 3.2V.
Figure 2 Camper Battery Bank in 16P1S Configuration for Top Balancing with Powerlab-8
2.2. State Of charge (SOC) and Charge Rates
State of charge (SoC) is the level of charge of a battery relative to its capacity. The units of SoC are percentage points (0% = empty; 100% = full).
Charge and discharge rates are often given as C or C-rate, which is a measure of the rate at which a battery is charged or discharged relative to its capacity. The C-rate is defined as the charge or discharge current divided by the battery’s capacity to store an electrical charge.
For example for a 100 ah cell you need to put 100 amps in for one hour to fully charge the cell at a 1C rate, slightly more in real world of course to make up for the small loses.
100 ah Battery:
1C = 100 amps, battery charged/discharged in one hour
.5C = 50 amps, battery charged in two hours
. 25C = 25 amps, battery charged in four hours
2C = 200 amps, battery charged in 1/2 hour
2.3. LFP Discharge/Charge Curve
One of the advantages of LFP cells is that the charge/discharge voltage curve where most of the energy is stored is very flat. For example below in Figure 3 below is the charge/discharge voltage verses time for cell-3 of my battery bank. These are 100 ah cells cycled using a PowerLab-8 battery workstation at 37 amps charge/discharge for a 0.37C rate.
NOTE: I used the Cellpro PowerLab 8 to automatically cycle each of the first four cells in my bank from the nominal 3.2V they arrived at to 3.6V, down to 2.9V then back to 3.6V to see how well matched they are.
Figure 3 Camper Cell-3 Discharge/Charge Voltage Verses Time
Shown is one cycle where the battery is charged starting at 0.0 hours to 3.6V close to 100% SOC, kept at 3.6V for 10 minutes, then discharged to 2.9V from 0.7 hours to 3.4 hours. The charge cycle from 2.9V starts at 3.4 hours to 5.8 hours when SOC back at ~100%. The charge/discharge are at 37 amps which is 0.37C for these 100 ah batteries.
2.3.1. Things to Note From Charge/Discharge Voltage Curve
Since the charge discharge voltage curve is so flat the only place you can reliably measure SOC from the voltage level is in the knees at the high and low SOC/voltage levels where the curve is steep enough to measure. The voltage level changes in the flat area are to small to measure accurately. Also note that the voltage levels in the flat area are very different on the charge(higher voltage level) verses discharge(lower voltage level) cycle. The higher the C rate the higher this difference.
2.3.2.The Steep Knees Voltage Region on Charge/Discharge
The steep part of the curve where the voltage changes rapidly at high and low voltage and SOC are called the knees. The knees are the dangerous part of the curve where you have to be care full not too over charge or under charge and damage the batteries. Also since such a short amount of time is spent storing energy in the knees you don’t lose much capacity if you stop charging/discharging when you first start entering the knee regions.
2.3.3.The Flat Useful Voltage Range
The flat voltage range is where almost all of the capacity is stored for LFP batteries. For my batteries at .37C the flat area is from 3.3V at 44 minutes to 3.1V at 3 hours on discharge and 3.3V to 3.4V on charge. On discharge the 3.3V to 3.1V level contains about 85 ah of the 100 ah spec’d for the battery. Figure 4 Camper Cell-3 Discharge/Charge Capacity ah Verses Time shows 98.2 ah total for 3.6V to 2.9V range for discharge. The batteries data sheet specify 3.65V max charge to 2.2V discharge range with 100 ah capacity. So using a safer charge/discharge range of 3.6V to 2.9V, verses 3.65V to 2.2V, you get 98 ah from these 100 ah batteries. I will be using 3.4V for max charge and 3.1V min for discharge so that the pack should have an extra long life. From my cell testing these are the points on charge/discharge when the knees start.
Figure 4 Camper Cell-3 Discharge/Charge Amp Hour Capacity Verses Time
3. LFP Safety
The main safety issue with LFP batteries is the danger of the battery catching on fire, this is called an “event”. The electrolyte in all lithium ion batteries is flammable when vented from the battery during an event. An event occurs if the battery gets heated up from an external or internal source causing the electrolyte to be expelled from the vent on the battery. An internal source of heat is a fault from within the battery like a short in the internal membrane. An external source could be a fire in the battery compartment or a heating element used to heat the battery up to failure for testing.
The LFP battery type is safer than other Lion battery types in that when venting occurs during an event the battery will not self ignite but the vented gas can ignite if an external ignition source is present so still is a fire hazard in certain siituations.
After spending a few months reading many white papers here are the main conclusion s I came too.
- Fire is the main danger from Lion Battery Banks caused by thermal runaway.
- Thermal runaway may be triggered if a battery has manufacturing defects that can lead to short-circuiting, is overheated, over charged, or is punctured
- During thermal runaway the electrolyte reacts with the electrode and releases flammable hydrocarbon gases
- LifePo4 cells chemical structure makes them less flammable since the gases expelled will not self ignite from high heat in the cell but can still be ignited with an external ignition source
- Once one cell fails in a battery bank and enters thermal run away it can heat up adjacent cells and potentially cause the entire bank to enter thermal run away, a bad thing.
- The larger the cell’s capacity in AH’s the more energy released on a thermal runaway event. This makes a battery bank made up of smaller cells less likely to have thermal runaway in one cell propagate to adjacent cells causing an event in the entire bank.
- Cylindrical Lithium Ion Cells are mass produced in very controlled conditions so per cell are more reliable than prismatic. Many of the cylindrical cells used for battery banks are designed with explosion proof stainless steel, flame retardant electrolyte and a thermal fuse so that an event in any single cell should not propagate to nearby cells if cell spacing is provided. The downside is that at 5 ah per cell it takes 20P4S config made up of 80 cells to make a 100 ah 12V bank. They also take up a lot more volume than prismatic cells so may not fit in the required space.
- For prismatic cells the larger size cells have larger internal structures making them more susceptible to damage from shock loads in RV and marine applications. Prismatic cells commonly range from 400 ah on the high side to lows of just a few ah’s. I chose 100 ah as a compromise to keep the cell count down to 16.
My main safety concern is an event in one of the cells causing it to overheat and expel flammable gas from it’s vent and having the gas ignite. This event can heat up adjacent cells causing other cells to vent and add to the fire threat. Since I am using a BMS to protect from over voltage my main concern has been a manufacturing defect that can cause an event over time.
The main things you can do to reduce the risk of an event causing a fire are as follows:
- Use a Battery Management System (BMS) with main contactor to cut the batteries off from charge/discharge sources when any cell goes over/under voltage or over temperature to prevent over/under voltage on cells. Over voltage can cause an event itself, under voltage can damage cells so that an event can occur in a later cycle.
- Monitor the cells voltage via BMS as they are charged/discharged and if any cell starts to drift away from the others you may have a cell that is failing.
- Have a method to vent any gasses expelled to the outside of unit.
- Have an insulator, like air spaces, between cells to prevent an event on one cell to heat up the other cells.
- A solid structure should be used around the cells to prevent damage to them from puncture, crushing etc.
To get an idea of what happens when an LFP type battery has an event the following videos are helpful.
Lithium battery test – ThunderSky Winston (Puncture, Overcharge, Short-circuit, Ignition)
Sinopoly Batterietest
Some of the best white papers I have found for safety information are:
A Review on the Thermal Hazards of the Lithium-Ion applsci-09-02483.pdf
https://www.mdpi.com/2076-3417/9/12/2483/htm
Experimental Analysis of Thermal Runaway and Propagation J. Electrochem. Soc.-2015-Lopez-A1905-15.pdf
http://jes.ecsdl.org/content/162/9/A1905.full
A General Discussion Of Li Ion Battery Safely
https://www.shockwavemotors.com/download/sum12_p037_044.pdf
Lithium-Ion Batteries Hazard and Use Assessment https://www.nrc.gov/docs/ML1719/ML17191A294.pdf
4. Bottom Verses Top Balance
When you build a Lion battery bank you will use all cells of the same ah capacity, in my case 100 ah. You want to use cells manufactured in the same lot to get the capacity as close as possible. Even with this there will be some difference in capacity between cells due to manufacturing variances.
Top balance simply means getting all cells in your bank at the same voltage at your maximum voltage level, bottom balance at minimum voltage. This is done by charging each parallel bank to the same voltage separately then tying them together in parallel for a day or two to let the voltage settle between them. You can find procedures for this on the web.
As you charge or discharge all cells in the series string will have the same amount of current flow through each cell. As shown for a discharge cycle in Figure 5 the cells with lower capacity will reach the knee first on the low voltage side since the lower capacity cell cannot store as much current over time as the others. If you continue discharging you can reverse bias the low cell and destroy it.
Figure 5 Cell Balancing
4.1. Why Balance Cells
Balancing cells is simply putting all cells in the bank to the same SOC at a selected voltage level. This will make the cells have the same SOC at this voltage point and have the widest difference in state of charge at the voltage level the farthest away from the selected point. The farthest points are the minimum discharge or maximum charge voltages.
4.2. Why Not Middle Balance
My first thoughts where that a middle balance would be best since you would have the SOC difference split between high voltage on charge and low voltage on discharge. The problem is that the only place you can easily measure SOC by voltage is in the knee regions at high and low voltage. So no middle balance.
4.3. Why I Chose Top Balance Verses Bottom
Many electrical vehicle users will say bottom balance is best since if you ever go to low on charge cycle you can easily reverse bias the weakest cell and ruin it. The consensus says that if you have a BMS to protect cells from high/low voltages it does not matter. Since my BMS has active balancing at high voltage I went ahead and top balanced.
NOTE: Many people say a BMS that balances cells is unnecessary. After running the camper bank for three months I would agree for our bank. With my top balanced bank at 20% SOC my batteries only show .01V difference at low voltage.
5. Host Camper House Bank LFP Design Elements
5.1. Top Level design
I already had installed (3)180W Mono solar panels and a Victron Smart Solar
100/50 in the camper before the LFP bank install. Victron is the only major
supplier of inverters, chargers etc that I could find that works with an external BMS battery manager that can control the charge/discharge cycle from it’s devices.
So I decided to go all Victron.
In general have been very happy with the Victron equipment and love the
direction they at taking with using Blue Tooth with your smart phone to manage their new products.
Also Victron is using the open source model for their documentation and user groups where you can find good user input.
https://www.victronenergy.com/live/start
My only complaint is that the build quality of the Mutliplus Compact
inverter was marginal at best. The AC connector terminal board was mounted very crooked and stacked weirdly on top of the main PCB. Almost returned it but after talking to Victron they said is should be OK and it does seem pretty solid. Could not really determine if they designed it this way(bad Mech engineering) or whether the contract manufacturer just assembled it this way.
In general stacked PCB’s should never touch like this other than through a
connector and the stand offs should be screwed down.
The first criteria I had was to fit a 400 ah 12V bank in the
battery box of the host camper. The box
normally holds two GC2 batteries.
| Camper Battery Box | Height | Width | Depth | |
| Inches | 13-15 | 22-23 | 7-9.5 (8.5 used max) | |
| mm | 330.2 | 558.8 | 215.9 |
The only type cells I could find to fit in the battery box with 400 Ah capacity where the aluminum encased 100 ah prismatic cells. The more common plastic encased versions where to large. The added benefit is that the aluminum encase cells dissipate heat better. I ended up using the Electric Car Parts EPC-100Ah-Fortune Battery where I can fit (16) cells in a 4P4S config. To fit in the space requires four cells to be bolted side to side to span the depth, then these four sets of cells are placed end to end to span the width as shown in Figure 7. The standard lugs are used to tie the terminal in the side by side config, for end to end the special non-standard lugs are required. The Non-standard version must jump across the plastic edges on the top ends of the cells.
Figure 6 Bus Bar Types
Figure 6-2 Bus Bar Types , Non-Standard and Standard
Figure 7 Prismatic Cell Placement
I chose to use the REC Active BMS which can directly control the charge/discharge cycle to the Victron series of MultiPlus Inverters and Smart Solar Chargers.
http://www.rec-bms.com/ABMS.html
As shown in Figure 8 System diagram the REC BMS controller is connected via the Victron VE.CAN Bus the Victron Color control CCGX. The BMS sends battery SOC info to the CCGX to control the charge and discharge cycles. The CCGX then relay’s this info to the Multiplus and Smart solar charger’s to manage the charge/discharge from each. The Multiplus has a VE.BUS interface whilst the Smart Solar has a VE.DIRECT interface.
The Victron CCGX is the central connection point via VE.BUS to the Multiplus, VE.CAN to the BMS and VE.DIRECT to the Smart Solar Controller.
All these connections use standard Ethernet RJ-45 cables which you can buy any where.
While the BMS controls the charge/discharge via the CANBUS I
also set the voltage levels for charge/discharge in the inverter and solar
charger as a secondary safety mechanism if the CANBUS mechanism fails.
I also included the REC precharge component to pre-charge
the large input capacitance of the inverter before the main contactor is closed to prevent arcing the contactor.
WARNING: I found out to late that Multiplus compact I bought does not have a separate voltage detect terminal wire interface to the battery, the full size Multiplus does. This means that the voltage is detected internally from the main current wire making the voltage reading dependent on the amount of current being supplied/drawn. I would not use one with out this since this really complicated the settings for Bulk/Absorb/Float. I had to run the inverter in charge and measure the delta at battery and inverter to figure charge setting at a higher level. Discharge is even harder since current varies more so still fine tuning setting minimum voltage for inverter on discharge.
A Sterling BB12-30 30 Amp DC to DC charger is used to charge
the bank from the truck trailer wiring 12V power. You can not directly connect the truck 12V power since the LFP bank impedance is so low it would draw to much current and fry the wire/fuse from truck. The Sterling is controlled from over charging the bank using a small signal relay TE V23105A5003A201 connected to the REC Active BMS “Charge Optocoupler Collector” output.
https://www.sterling-power-usa.com/SterlingPower12volt-12volt-30ampbatterytobatterycharger.aspx
I would highly recommend buying the Blue Tooth interface for
the REC BMS which enables you to use your phone to monitor the BMS. You do have to use the cable to a dongle on your PC to set up the BMS.
The Smart Solar Controller from VICTRON also has a Blue
Tooth interface that is very use full for setting up and monitoring the
controller.
In the future I will want the Blue Tooth Interface for all components if possible. The Victron Multiplus lacks this feature and you have to cable to it with the MK3 VE Bus dongle which is a bit of a hassle since you have to disconnect VE.BUS cable from Multiplus to CCGX and connect to dongle.
https://www.victronenergy.com/inverters-chargers
https://www.victronenergy.com/solar-charge-controllers/smartsolar-100-30-100-50
LifePo4 battery protection at four levels:
- REC BMS CANBUS Active Control
a. REC BMS controls Victron Smart-Solar MPPT and Multi-Plus C 12/2000/80 charge/discharge current over VE-CAN bus via CCGX.
2. REC BMS OptoCoupler and Relay outputs
a. REC BMS disconnects other charge sources via REC BMS “Charge Optocoupler Collector”, Opto’s drive 15 ma.
b. REC BMS disconnects other load sources via REC BMS “Relay-1 NO”, Relay-1 drive 0.7 amp
3. Voltage levels set for max charge minimum discharge on all sources/loads
a. Load, Victron inverter voltage DC input minimum cutoff input set, Victron Battery Protect minimum voltage
b. Source, Victron Multiplus, SmartSolar and Sterling BB1230 Bulk/Float max voltage level set
4. “Main Contactor” opened if protection levels 1,2 fail to prevent over or under charge.
Figure 8 Camper System Diagram
5.2 Electric Car Parts
Company ECPC-100Ah-Fortune Aluminum Encased Battery
After looking at many options I selected the 100Ah Fortune
aluminum encased battery from ECPC. All prismatic cells are manufactured and sold in china. I could find cells directly shipped from Alibaba or from some suppliers directly for slightly cheaper but if any problem comes up with a cell you may be out of luck.
Also the quality and getting well matched cells from same lot is in
question.
After talking to Carl at ECPC, where he has traveled to the
manufacturer and seen good quality testing etc and the fact that he will
replace suspect cells, I ordered (16) of the 100 Ah cells from ECPC.
https://www.electriccarpartscompany.com/Fortune-100Ah-Aluminum-Encased-Battery
I used the Cellpro PowerLab 8 to automatically cycle each of the first four cells in my bank from the nominal 3.2V they arrived at to 3.6V, down to 2.9V then back to 3.6V to see how well matched they are.
http://www.store.revolectrix.com/Products/Cellpro-PowerLab-8-EC5-version
Figure 9 Testing Cell With Powerlab and Lap Top
The Powerlab can supply up to 40 Amps current for charge/discharge. For 40 Amp discharge requires external lead acid batteries. I used two old deep cycle 6V batteries for this purpose. Since these batteries are old and could not supply enough energy for full charge/discharge/charge cycle I ended up adding a battery charger set at 5 amps to the batteries to run a full cycle.
The capacity of the first four cells is below for 2.9V to 2.6V at 37 Amps, this is a max 2.4% difference between max capacity of 98.7 Ah to min 96.3 Ah. Would like 1% or less but part of the 2.4% is from the test equipment, how much I do not know. From using the bank in the camper for the last three months the cells have tracked to 0.01V at 20% SOC which I am very happy with.
Cell1 = 96.3 Ah
Cell2 = 98.7 Ah
Cell3 = 98.2 Ah
Cell4 = 97.9 Ah
6. Good links for LFP Information
- Marine How To, best site found for marine installations and general info on LFP house banks
- Battery and Energy Technologies, knowledge base of battery information
- Supplier of drop in replacement LFP batteries, good info on their site
- Battery Bro Web Site, This is a very long (10,000 word, 60 image) blog post transcribing a lecture by professor Jeff Dahn from Dalhousie University titled “Why do lithium-ion batteries die, and can they be immortal?”
7. Set Up And Testing
7.1. REC Active BMS Set Up
The REC Active BMS requires the REC BMS PC Master Control
Software and USB cable to RS485 adaptor to perform set up. All main charging parameters can be changed via the tool. I used the RELAY-1 output to control the Victron which you have to use low level commands to set as shown below.
| relay 1 voltage level 3.58 V | 3 | RE1L 3.00 | |
| relay 1 voltage level hysteresis -0.2 V | 0.2 | RE1H -0.20 |
7.2. Sterling BB1230 Set Up
The set up for the Sterling devices is done with two buttons
and the front panel LED’s for feed back.
Very simple which is good but the down side is that as you have no feed
back on the settings once you make them to check all OK. Just read the manual on the procedure on programming
the device.
7.3. Victron Multiplus(MP) Set Up
To set up the multiplus(MP) you need to disconnect the RJ-45
cable going from MP to Color Control CCGX and connect this to the VE.BUS on USB MK3 dongle to your PC. On the PC you need to download the VeConfigure utility. In the utility you will need to go through the tabs shown below to program the settings you require.
Figure 10 Multiplus General Tab
When you first connect to the MP in the general tab you will want to click the “Get settings” tab to fetch the setting currently residing in the MP and display in the VE Configure tabs. Once complete with changing settings
in all the tabs you need to go back to this tab to “Send settings” back to the
MP. The only setting I needed to set here is for the 30 Amp AC input current limit to match my 30 Amp connection on the camper.
Figure 11 Multiplus Charger Tab
In the MP “Charger Tab” you will want to check the “Lithium
batteries” box, the only thing I could find what this does is make the Charger switch from float back to bulk 0.2V below “Float Voltage”. If set to lead acid, switch to bulk 1.3V below “Float Voltage”. With LFP narrow
voltage curve you want the charger to kick in sooner at 0.2V. What happens here is that the Charger charges battery bank up to the absorption voltage level then cuts off. The battery Charger then will not start
recharging the batteries until float voltage – 0.2V is reached which may cycle your battery more than you might want. I changed the float level from the 13.2V shown to 13.4V to match my minimum voltage level of 3.1V per cell. Also when the system was installed I changed the “Absorption voltage” tho 14.2 from 13.9V to make up for the voltage drop from MP to battery of 0.3V when charging at 70 Amps. Would not use the Compact
version of MP again since the sense wire connection to battery is deleted on
the compact version, this SUCKS! Just left the abosrbtion time at one hour since BMS should control final charge
voltage.
Figure 12 Multiplus Inverter Tab
On the “Inverter Tab” the main thing is to set the “DC Input
Low Shut Down” where the inverter will stop inverting and shut down the AC output when the DC voltage drops below this value. Since the current for discharge is in to inverter at up to over 100 amps, verses out for charger, I had to drop input low shutdown to 11.5V and low restart to 12.5V verses what is shown above. No voltage sense wire problem AGAIN! I also did not enable AES for saving power at low AC currents since did not want to deal with it. Did leave power assist on so that if over 30 Amps drawn by Inverter from shore AC the inverter will draw the extra power from batteries if required.
Figure 13 Multiplus Grid Tab
On this screen I originally left everything at default as
above. Once I tested system with AC shore power all was good but when I tried generator AC power in the inverter charger would not accept the AC. Generator AC is noisy/dirty and can drift off the 60 Hz.
To get generator AC input to work I had to check “Accept Wide Input
Frequency” and unchecked “UPS Function”.
The UPS function to cut in AC with no interruption in power evidently
requires cleaner AC inputs.
https://www.victronenergy.com/live/multiplus_faq
7.4. Victron MPPT 50/100 Set Up
The set up and monitoring MPPT is very simple due to the
Blue Tooth interface to your smat phone.
Simply down load the Victron Connect App to your phone and pair it to
the MPPT via Blue Tooth. To perform the
set up you will need to use the default VictronConnect PIN of 000000.
Figure 14 Victron MPPT Blue Tooth Interface
Main Page
Simply select the gear symbol in the upper right corner of the main page to set up your parameters as shown in Figure 14
Figure 15 Victron MPPT Settings Page
7.5. Victron Color Control CCGX Set Up
The CCGX is actually very simple to configure for the BMS to
be the Battery Monitor and control the MPPT and Mutilplus charge/discharge cycles.
Once you have the REC BMS, MPPT and Mutliplus wired up to
the CCGX you power the sytem up by turning on the BMS with the on/off switch wired in too the BMS. You will hear the main contactor click as the BMS connects the battery bank to the 12V bus bar providing power to the inverter, CCGX and MPPT.
Figure 16 Victron CCGX Main Page
Once powered up the Main Page will come up showing all the
devices connected to the CCGX, here showing BMS bottom left and MPPT charger bottom right and Multiplus top middle. When first brought up you will not always see the BMS Battery Monitor on the bottom left until you have configured the CCGX.
Figure 17 CCGX Device List -> Settings
First go to “Device List” then “Settings”.
Figure 18 Settings -> Services
From “Settings” go to “Services”.
Figure 19 CCGX Services Can-Bus Profile
In “Services” set CAN-Bus Profile to VE.CAN & Can-Bus
BMS to 250 kbits/sec.
The last step is to go to System Setup and select REC-BMS as
the Battery Monitor for the system. I also set the following:
“Synchronize VE.Bus SOC with battery” = “On”
“Use solar charger current to improve VE.Bus SOC” = “On”
“Solar charger current control” = “Off”
(Parameter Definition From CCGX Manual)
“Synchronize VE.Bus SOC with battery” –
Continuously copies the SOC from the battery monitor to the VE.Bus system. This feature is automatically enabled when the active SOC source is not a VE.Bus device, and there is no Hub-2 Assistant configured. The purpose of this is to be able to use the BMV SOC to trigger some Multi or Quattro features – such as Genset start/stop. Multis and Quattro’s don’t use the SOC for any other purpose. More information
“Use solar charger current to improve VE.Bus SOC” –
Send the total charge current from all connected Solar chargers to the VE.Bus device to improve its SOC computations. This feature is automatically active when ‘Synchronize VE.Bus SOC with battery’ is not active.
“Solar charger current control” –
Limit the charge current of the connected solar chargers if a CAN.bus BMS is present – using the maximum charge current information provided by the BMS.
Figure 20 CCGX System Setup Enable REC
BMS As Battery Monitor
Figure 21 Device List All Devices Present
You should now see all three devices on the “Device List” page after the BMS has been configured.