Originally Posted by jimtwilliams1226
My 2007 Roadtrek SS Agile house batteries will not charge while driving. They will full charge when plugged into 110v power. While checking the elec diagram I noted a Battery separator and several breakers. Where is the battery separator located? Any info on trouble shooting the charging issue is welcome.
We had the same problem when we bought our used 2016 PW Lexor - the coach batteries were not charging while driving. It turns out that the 150 amp fuses between the separator and the chassis batteries were blown. These were located under the hood, inline with the red charging cables (on the left in the photo) going from the separator to the coach. After replacing the fuses, I discovered that the separator was not working and so I replaced it. If you have a solenoid based separator like is in out Lexor (SurePower 1314-200), you should hear it click closed a few seconds after starting the engine as the voltage goes above 13.2 volts. That is an indication that the chassis and coach batteries are connected and both charging from the alternator. A few seconds after turning off the engine you should hear it click open as the chassis battery voltage drops below 12.6 volts, effectively separating the battery banks. I suspect that someone accidentally shorted something to the chassis before we purchased the RV, damaging the separator and blowing the fuses.
All that said, I have replaced the separator with a Cole-Hersee 75920 manual disconnect switch and am using a Renogy 60 amp DC-DC charger, managed by a slick device I learned about on this forum
. This set up reduces the total current load placed on the alternator and maintains the automatic switching based on alternator operation. With the old set up, when the LiFePO4 batteries were depleted it would be common to have 150 amps going from the alternator to the coach and now that maxes out at about 75 amps and I can limit to half that if necessary. I leave the manual switch closed (on) unless the unit is in storage, when I turn it off to completely isolate the chassis battery from the coach.