Believe your 2016 I3 is an MBS based Motorhome, as is my 2012 Solera. Don’t know if Forest River made any significant changes to the battery system in those years. I converted mine and reported on it maybe four years ago. My report from back then:
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With thanks to several here, particularly rk06382 and Riverbend, I completed converting my 2012 MBS Solera to Battleborn LiFeP house batteries today. All functions appear to be working as planned. Of course, my conversion is a mix of several other’s approaches.
I decided to go directly to two 100 amp-hour Battleborns in parallel.
First, I did change the converter from the factory WFCO to a PD 60 amp lithium converter. While Battleborn shows the WFCO as compatible on their website, comments indicate that the fact that the WFCO rarely goes into bulk mode - and therefore doesn’t deliver the 14.2 to 14.6 volts Battleborn wants for balancing - convinced me to make the change. Turns out ForestRiver mounted the WFCO above the water heater in a spot only accessible by partially disassembling the rear main storage compartment (had to take out two interior storage compartment walls). Also, the PD converter is larger and would not fit as the WFCO was mounted. Switched from vertical to horizontal mount to fit the PD in.
Second, I chose to go with the Renogy DCC1212 20 amp device for alternator charging. From a Sprinter forum, I understand Mercedes says 40 amps maximum from the stock alternator for auxiliary battery charging. I believe the 200 amp-hours of Battleborns, if significantly discharged, could easily draw more than 40 amps from the alternator through a BIM. The Precision Circuits Lithium BIM attempts to address this by only engaging for 15 minutes out of every 35 minutes- an approximate 43% alternator duty cycle. Still, during the 15 minute “on” period, the alternator draw could exceed the Mercedes guidance. (Of note, on the Sprinter forum, many members appear to violate this guidance with no problems.) Renogy specifies that their devices draw 50% more input current than they deliver - so the 20 amp Renogy would draw 30 amps (maximum). On bench testing I measured ~27 amps in, and almost exactly 20 amps out. Also measured <100 micro amps on input when off. (Of note, if the Mercedes alternator was somehow limited to the recommended 40 amps, it would deliver about 17 amps average through the Precision LiBIM - 43% of 40 amps - while the Renogy delivers 20 amps average. The Renogy is also less expensive - about $130 vs about $170 for the LiBIM).
To implement the Renogy, I first disabled the factory BIM interconnect relay by disconnecting the wires to the non-grounded side of the relay’s coil. The factory Battery Control Center - on the side of the stairs on my MH - controls and fuses a number of functions (slide out, stairs, awning, ...) that I didn’t want to interfere with. Disconnecting the battery interconnect relay left all these functions intact, while preventing the BIM from connecting the chassis and house batteries together. I used the main terminals on the interconnect relay to source chassis alternator power and to connect the Renogy output to the Battleborns (both appropriately fused).
I also tapped into the “ignition” identified tap in the BCC to supply a trigger voltage for the Renogy. I installed a one to five minute delay relay between the ignition signal and the Renogy so the vehicle is started and stabilized before the Renogy starts loading the chassis battery/alternator system. ( It appears the ignition signal only comes on after the engine has started, so the delay relay may be unnecessary.)
Third, reconfigured my Renogy 100 watt solar with PWM controller. My primary use of the solar is to maintain my batteries during extended (4 to 12 week) storage intervals. As Battleborn does not recommend continuous charging, this becomes a chassis battery issue. I wired my controller to a SPDT center off switch, so I can switch my solar charge between the chassis battery and the house batteries. My controller has adjustable cutoff voltage - I set it for the chassis AGM maintenance (~13 volts). Should I want to direct it to the house batteries, say while boondocking, I can flip the toggle switch and adjust the cutoff voltage up to Battleborn’s recommended 14.4 +/- .2 volts.
I went with the $22 BangGood 300 amp battery monitor. It gives battery voltage (including a bar graph), current flowing through the shunt, and calculated total amp-hours through the shunt. It doesn’t differentiate between current flowing into or out of the battery - NOT a “battery fuel gauge”. Seems quite accurate vs my benchtop meters. I may eventually upgrade to a “battery fuel gauge” type if I find this is too limiting- or I may find this one is satisfactory.
My install eliminates converter charging of the chassis battery, and would disable the switch some have to connect the chassis and house batteries for “emergency start” purposes. My MH never had the “emergency start” switch, so no loss there. My solar modification for chassis battery maintenance and carrying a small lithium “jump starter” is my plan. ( I could easily open the BCC and jump the interconnect relay if I really had to... in 8 years and 98,000 miles I haven’t needed it yet.)
Parts I used:
Converter:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Renogy DCC1212:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Delay Relay:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Battery Monitor:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Again, thanks to those who shared their Battleborn experiences-
Hope this is useful to someone, as your posts have been to me.
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The conversion has worked well for me. I did later replace the BangGood battery monitor with an Aili “battery fuel gauge” monitor:
https://www.amazon.com/AiLi-Voltmete...95&sr=8-3&th=1
I also later added a 2K watt inverter, which allows me to run the microwave without starting the generator.
FYI, Jim
Linear Mode
