LiFePO4 and B2B Charger Issues
Hi - Having recently converted my Flagstaff T12RB PUP to a LiFePO4 battery I'm learning the hard way that my tow vehicle (2016 Highlander) will not fully charge this battery. So, bottom line: I need to install a Battery-to-Battery charger to better manage the 13VDC output from the tow vehicle and bump it up as needed to meet charging requirements for the LiFePO4 while on the road. I would really appreciate some help with this since Renogy's instructions are specific to "inhouse" (i.e. vans and motorhomes), and Forest River will not provide schematics (of course). My questions are:
1. Since I'm mounting the B2B charger (a Renogy 20A) in the trailer, can I (or should I) redirect the "Battery Charger" lead (Pin 4) from the 7-way connector so that it feeds the +DC input of the B2B exclusively?
2. Can I assume that the same ground can be used (shared) on the -DC Input and -DC Output sides of the charger?
3. The B2B unit will be mounted next to my solar controller (which has existing 3' 8AWG hardwired on the output side directly to the battery), so can I piggyback the B2B outputs onto the existing wiring from the solar controller (wired in parallel, of course), and thus avoid additional wire runs to the battery?
4. By design, my Prodigy brake controller does not pass current between the tow vehicle and the trailer on Pin 4 (the "Battery Charger" lead) unless tow vehicle's ignition is "On". If I feed +DC input of the B2B unit with this lead, can I also use it for D+ Ignition connection to the B2B?
Sorry for the wordy post; hope somebody who's figured out this puzzle and found it interesting can share some words of wisdom.