Bill (DesertDust) is having an issue with the chassis battery and isolation of his house batteries. The old style, That I believe was used in the '80's by LD, was maybe adequate back then. Robot or human? (https://www.walmart.com/ip/200-Amp-Heavy-Duty-High-Current-Power-Performance-Dual-Battery-Isolator-Relay-Us-12V/13618611577?wmlspartner=wlpa&selectedSellerId=102632132) My 1999 has an 120Amp diode isolator. I had corrosion problems with one connection under the hood, but it still works. The factory switched to a much better type of relay to handle higher loads: https://www.supplyhouse.com/White-Rodgers-586-108111-Solenoid-SPNO-15-VDC-Isolated-Coil-Normally-Open-Continuous-Contact-Rating-200-Amps-Inrush-600-Amps?gclid=Cj0KCQiA0eOPBhCGARIsAFIwTs4gQws6LzxHDOujEFj9i1F0ccfuzbDUgO1hi70607__L02wturKK7kaAju_EALw_wcB and that should do well.
For Lithium batteries and large charging current, at least one customer of AM Solar had this one installed: LiFePO4 Battery Isolation Manager (BIM) | Battle Born Batteries (https://battlebornbatteries.com/product/lifepo4-battery-isolation-manager/?gad_source=1&gad_campaignid=20653326203&gbraid=0AAAAADN-aZmx72cl9tWbWXi1XoNfVNsC-&gclid=Cj0KCQiAxJXJBhD_ARIsAH_JGjhFHO8vOQ8ByQnJYcqVFU56jJjO7lhryHwm56IQneRl2pigrUv4C18aAhJUEALw_wcB) . This smart relay connects and disconnects depending on the level of voltages present. It limits the duty cycle to lower stress on the engine alternator. RonB
The problem with relays that connect the batteries together is that LFP and lead-acid batteries have different voltages at different states of charge. Unless the chassis battery is significantly discharged, little charge will end up going to the LFPs. All the Battleborn device will do is prevent the LFPs from discharging into the chassis battery. A diode isolator is a simple device with no moving parts, and can effectively prevent cross-discharge between the batteries. The voltage drops across the device allows better charging of the LFPs, though there is power wasted due to thermal losses in the isolator.
Steve
Thanks for that Steve. Makes sense. I took out my diode isolator, and that wire goes back to my Renogy DC to DC 60A converter. (I throttled that back to 30A using the 'LC' control input. ) An original LD 100A breaker before it feeds into the Renogy. That converter has DIP switches to select a LiF battery charging profile. So far so good. RonB
Bill (DesertDust) is having an issue with the chassis battery and isolation of his house batteries. The old style,
Not really an issue - just wanting to assure it has one and where it is. I need to run a wire to the 7 pin trailer connector both to power the electric tongue jack and to service the battery that I'll be installing to power a winch- although I may just install a solar panel for that. I wanted to assure I was tapping the house battery to protect the engine battery, just in case.
There is nothing wrong using a BIM but it may don't be needed, especially on a older rig that uses a diode isolator. Around 2007-08 LD changed to the relay isolator
I believe our LD's isolator diode is rated at 150-amps and has not failed after several years charging 200-amp/hours of lithium and later 400-amp/hours of lithium. The 130-amp alternator is still working fine, even after charging deeply discharged batteries many times. over almost four years of use. I have used the added battery switch to bypass the isolator to see if the if it increased the number of amps going the batteries. Surprisingly, the increase wasn't much.
As I have mentioned many times, alternators derate as they get hot, preventing burnouts from overloading. Alternators can burnup from direct shorts, this is why they are protected by fusible links.
Larry