Li Fe Battery For RV design issue

[j-c-c-62]

So I'm building/converting a 40' Flat front School bus in a Combo RV/ Internal race car ramp hauler.
Besides the current 12V system, I am planning a two other independent battery systems, one 12V to 120VAC for "essentials" like refrigerator, interior lighting, TV, clock, etc, and another 48V to 120/240VAC main system for AC, Air Compressor, Water heater, water pump, and it will backup the "essential" system.
The essential system will be also be full time backed up by the trucks 12V system, so anytime the truck is running it can supplement and or charge the essential system. Both systems will have their own independent solar panels, roof mounted, 320 & 2560 watts respectively.

The issue I am trying to head off is with the essential battery system first, regarding battery fire safety. I want to mount the LI 400AH 12V battery in the RV existing steel battery box, near the front, outside the enclosed space. My safety purposed thinking is to incorporate a physical drop system so an ignited battery can drop out the bottom, with some sort of self-disconnecting power leads (max 12V draw is 300A for 10 Sec) to give some distance from a burning battery, and maybe allow the RV to be moved away the inflamed battery. RV is diesel, the OEM tank is 20' away currently. Depending on how this essential battery mounting/hookup solution works out, will guide me as to the main system later.

I am committed to the Li FE battery for many reasons on this project, not negotiable. I originally had an idea to rebuild the original battery box out of stainless, and install an internal nozzle and plumb it to a remote fire department 2"? hose connection permanently mounted on the RV.

I asked a local fireman what universal connection he would suggest to have the greatest chance a direct Fire Truck hook up could be made.

He was not too keen on the whole idea, thinking by the time they arrived it would be almost all over, nobody would know/understand what the heck they were looking at and would be very skeptical since they had never seen anything like that before, and I would be ordered away from the fire scene danger and nobody would listen to me as a civilian.

So my next thought is simply to drop battery on the ground to improve my odds in a better outcome. This Li battery weights 56 lbs. I would need an exterior mechanical non powered pull pin set up at least from 10' away?

Anyone seen something this? Any comments/thoughts?

 

[Triplegreen500]

Install a diesel generator.

Easy to source, common product for repair and maintenance (and emergency - first responders will know EXACTLY what to do), puts out the voltage you require on the systems you plan to use, and runs off the same fuel as the chassis (and compared to the chassis, it SIPS that fuel). Put its pickup at the 1/4 tank level so it will shut off with enough fuel to get the unit to a fuel station.

 

[Richard Cranium]

I asked a local fireman ......

He was not too keen on the whole idea

I can't imagine why?

 

[j-c-c-62]

I can't imagine why?

He told me, "thinking by the time they arrived it would be almost all over, nobody would know/understand what the heck they were looking at and would be very skeptical since they had never seen anything like that before, and I would be ordered away from the fire scene danger and nobody would listen to me as a civilian."

 

[68 Sport Satellite]

So I'm building/converting a 40' Flat front School bus in a Combo RV/ Internal race car ramp hauler.
Besides the current 12V system, I am planning a two other independent battery systems, one 12V to 120VAC for "essentials" like refrigerator, interior lighting, TV, clock, etc, and another 48V to 120/240VAC main system for AC, Air Compressor, Water heater, water pump, and it will backup the "essential" system.
The essential system will be also be full time backed up by the trucks 12V system, so anytime the truck is running it can supplement and or charge the essential system. Both systems will have their own independent solar panels, roof mounted, 320 & 2560 watts respectively.

The issue I am trying to head off is with the essential battery system first, regarding battery fire safety. I want to mount the LI 400AH 12V battery in the RV existing steel battery box, near the front, outside the enclosed space. My safety purposed thinking is to incorporate a physical drop system so an ignited battery can drop out the bottom, with some sort of self-disconnecting power leads (max 12V draw is 300A for 10 Sec) to give some distance from a burning battery, and maybe allow the RV to be moved away the inflamed battery. RV is diesel, the OEM tank is 20' away currently. Depending on how this essential battery mounting/hookup solution works out, will guide me as to the main system later.

I am committed to the Li FE battery for many reasons on this project, not negotiable. I originally had an idea to rebuild the original battery box out of stainless, and install an internal nozzle and plumb it to a remote fire department 2"? hose connection permanently mounted on the RV.

I asked a local fireman what universal connection he would suggest to have the greatest chance a direct Fire Truck hook up could be made.

He was not too keen on the whole idea, thinking by the time they arrived it would be almost all over, nobody would know/understand what the heck they were looking at and would be very skeptical since they had never seen anything like that before, and I would be ordered away from the fire scene danger and nobody would listen to me as a civilian.

So my next thought is simply to drop battery on the ground to improve my odds in a better outcome. This Li battery weights 56 lbs. I would need an exterior mechanical non powered pull pin set up at least from 10' away?

Anyone seen something this? Any comments/thoughts?

If you're planning to use the LiFePO4 battery and not a Li Ion battery, you should be fine and not be as concerned about fire. These Lithium batteries are not extinguishable by water anyway. Here's the fire dept comparison video that sold me on either a LiFePO4 (LFP) or Lithium Titanate (LTO) type battery for my car.

 

[Kernel Sanders]

I'm kinda confused on your plan to drop the battery in case of fire. These LiFePO batteries (like others) need to be wired in so even if you wanted to drop them out in the case of a fire, the wiring itself will not allow that to happen effectively.

Sorry went back and read that you'd use some sort of wire disconnect... Hmmm connections like that may have their own issues like introduced resistances causing heat and fire in and themselves.

Personally I think your over designing (that's just my opinion)

PS, I do have a similar system in my travel van. I run from my alternator to a DC to DC (current limited to not over draw current) converter to charge a secondary battery for a 2000W inverter to run a microwave and coffee maker for when I travel on the road and camp. I can put panels on the roof and put in a charge controller in to supplement but haven't just because the point is travel and the secondary battery is charged every time i run the van so there was no point.

 

[Hey-O]

Rv's have been around along time and if it's not broke, don't try to fix it, little sense in reinventing the wheel. I would follow suit and get a diesel generator that feeds straight from your diesel tank. Been down this road. Enjoy and have fun, I get it. Everytime my wife and I drive by the u-haul dealer by me and I see a 28 footer without a box for sale, my wife says, don't even think about it.
Ultimate RV Battery Guide - RVing Beginner

 

[j-c-c-62]

Yes, I'm using the LIFEPO batteries.
My thinking was the weight of the battery (56?lbs?) would facilitate the separation of the quick disconnect linked below, rated at 175A, although I believe they make higher rated versions.
Your point about any connection adding another source for potential problems I agree has a lot of merit.

175A Battery Connector AWG 1/0 Quick Connect Battery Modular Power Connectors Quick Disconnect (Grey) Amazon​

I hear the "over design" comment often.
Thanks

PS, a backup small diesel genset is the final addition to the plan, after i get some real time power usage needs, so I can properly size a unit.
The solar power RV will be a quick escape vehicle for Florida hurricanes, and basic electrical power upon return with typical extended post hurricane power outages.