Question on battery wireing 19'

[NEWYORKHILLBILLY]

Is there a junction box or something between the battery and battery switch?


I want to relocate a lithium battery into the drivers side dinette close to the battery switch. I was assuming this would not be any problem as all the wiring should be there. The way i understand it is the safety Breakaway switch is wired to the battery before the switch. I been looking over pictures and I can only see two wires coming from battery (pos +neg) out of front storage box. So i thinking there has to be a junction box? If there is a junction box is that covered with the spray foam?

[Greg A]

I’m working on this on my 19, but have the classic so not sure if it is the same.
There is a Junction box in our DS bench. The + line comes in to trailer, the negative goes to frame ground on DS. Putting in the new blue seas switch and BMV712 battery monitor. Building a ply base for the battleborn dimensions 2-100ah, under DS bench and attaching shunt to the battery board. For now, will bring negative into trailer to shunt for existing 6v’s, then later when I drop the Battleborns in it will be simple.
Still need to add the pda wildcat module to the converter and change out to the Victron mppt 100/30 controller.
I’ll purchase and drop the new batteries last sometime next spring and it should just be plug n play at that point. Will get close to 6 years out of the original 6v’s when I switch.

[NEWYORKHILLBILLY]

Originally Posted by Greg A

I’m working on this on my 19, but have the classic so not sure if it is the same.
There is a Junction box in our DS bench. The + line comes in to trailer, the negative goes to frame ground on DS. Putting in the new blue seas switch and BMV712 battery monitor. Building a ply base for the battleborn dimensions 2-100ah, under DS bench and attaching shunt to the battery board. For now, will bring negative into trailer to shunt for existing 6v’s, then later when I drop the Battleborns in it will be simple.
Still need to add the pda wildcat module to the converter and change out to the Victron mppt 100/30 controller.
I’ll purchase and drop the new batteries last sometime next spring and it should just be plug n play at that point. Will get close to 6 years out of the original 6v’s when I switch.

not sure if the classic would be the same. sound like you going to have a nice set up when its done.

[Greg A]

TY, I’m looking forward to following your install. You should be a bit ahead of me if China gets the stuff shipped.

[NEWYORKHILLBILLY]

Originally Posted by Greg A

TY, I’m looking forward to following your install. You should be a bit ahead of me if China gets the stuff shipped.

The boat from china is like 30 days but then it can sit in U.S. customs for a for weeks. my trailer has not entered production yet so you still might beat me.

[Doug2000]

I asked my engineers at work about Lithium in a RV, the response was, not if you want to live. Many of the Engineers I work with are scared of Lithium.

Personally I plan on 2 AGM's under the dinette when the flooded battery dies.

[NEWYORKHILLBILLY]

Originally Posted by Doug2000

I asked my engineers at work about Lithium in a RV, the response was, not if you want to live. Many of the Engineers I work with are scared of Lithium.

Personally I plan on 2 AGM's under the dinette when the flooded battery dies.

These are Lithium Iron Phosphate there probably thinking of of other types Lithium. those agm can also vent inside if over charged


quick google search brings up


huge improvement over lead acid in weight, capacity and shelf life. The LiFePO4 batteries are the safest type of Lithium batteries as they will not overheat, and even if punctured they will not catch on fire. The cathode material in LiFePO4 batteries is not hazardous, and so poses no negative health hazards or environmental hazards. Due to the oxygen being bonded tightly to the molecule, there is no danger of the battery erupting into flames like there is with Lithium-Ion. The chemistry is so stable that LiFePO4 batteries will accept a charge from a lead-acid configured charger




Lithium-Ion batteries and Lithium Polymer batteries do have some safety concerns

[Brian B-P]

Originally Posted by NEWYORKHILLBILLY

These are Lithium Iron Phosphate there probably thinking of of other types Lithium.
..
The cathode material in LiFePO4 batteries is not hazardous, and so poses no negative health hazards or environmental hazards. Due to the oxygen being bonded tightly to the molecule, there is no danger of the battery erupting into flames like there is with Lithium-Ion.
..
Lithium-Ion batteries and Lithium Polymer batteries do have some safety concerns

Just to clarify some of these common errors in terminology...
Lithium iron phosphate (LiFePO4 or "LFP") is a lithium-ion battery chemistry - all of the other elements and compounds named are part of the cathode (positive electrode) composition. There are many cathode compositions, but the cells made from them are all lithium-ion. LFP is generally considered safer than the higher-performance chemistries used in electric cars (such as NMC and NCA), and in other devices (such as NCO), because LFP tend not to overheat when overworked or damaged, and when it gets hot it has a low tendency to make itself hotter (which is called thermal runaway). So, sure, LFP is clearly safer than other lithium-ion batteries, but they're all lithium-ion.

An FAA test report demonstrated the greater thermal stability of LFP, but also showed that they experience thermal runaway, too; fortunately, that stability meant that thermal runaway did not propagate to adjacent cells. It also showed that all failed non-polymer cells produced flammable gas on failure. Electric cars have battery cases which contain gases and vent them if required in a controlled way; I have yet to see a lithium drop-in replacement battery which has any such provisions, beyond a sealed plastic box.

The "polymer" in "lithium-polymer" (or "Li-po") cells is the electrolyte between the electrodes. Lithium-polymer cells are lithium-ion cells; their electrolyte is just polymer gel rather than the usual organic solvent (which is flammable). Polymer electrolyte cells are usually used in mobile devices and remote-controlled stuff ("drones", etc), but have been used in some electric cars (Hyundai seems to like them). In cars, polymer cells have not been a safety problem, but the quality control and battery monitoring are very different between toys and cars; the lithium-polymer battery's reputation for being dangerous is probably based on severe abuse of poorly-constructed batteries in less stable chemistries.

[Brian B-P]

Originally Posted by NEWYORKHILLBILLY

quick google search brings up

This statement is complete nonsense, raising substantial doubt about the competence of the source. By source, of course I mean whatever web site the search found, not the forum member who posted it.

The reason - and the only reason - that a charger intended for a lead-acid battery can be successfully used with a LiFePO4 battery is that the voltages correspond reasonably closely for the nominal voltage used in RVs. This has nothing at all to do with stability.

The explanation:

A lead-acid battery runs nominally (less when discharged, more when fully charged) 2 volts per cell, or 12 volts for the six-cells-in-series batteries used in RVs. A LiFePO4 cells runs nominally about 3.2 volts per cells, or 12.8 volts for the four-cells-in-series batteries used to replace lead-acid batteries in RVs. The voltage difference is okay because the LiFePO4 changes less in voltage as it changes in state of charge, so the fully-charged voltage is a decent match. Other lithium-ion cell chemistries usually run around 3.75 volts per cell, so the voltage of three cells in series wouldn't be high enough (only 11.25 V nominally, not much over 12 V fully charged) but the voltage of four cells in series would be too high (15 V nominally, over 16 V to get it fully charged).

If the system were running at a higher voltage, a combination of cells of other chemistries could work. For instance, a "48 volt" lead-acid battery has 24 cells in series, and could be replaced by either 16 LiFePO4 cells in series (51.2 V nominal), or by 13 to 14 NMC or NCA lithium-ion cells in series (48.75 V or 52.5 V nominal)... but 13 or 14 doesn't divide neatly by four to make a usable replacement for a "12-volt" lead-acid battery.

Just like any other lithium-ion battery type, and unlike any lead-acid battery, a LiFePO4 battery needs a management system monitoring individual cell voltages, with high-voltage, low-voltage, high-current, and low (and perhaps high) temperature shutdown features... which is why such a BMS is always included in the lithium battery systems for RVs.

[NEWYORKHILLBILLY]

Originally Posted by Brian B-P

This statement is complete nonsense, raising substantial doubt about the competence of the source. By source, of course I mean whatever web site the search found, not the forum member who posted it.

The reason - and the only reason - that a charger intended for a lead-acid battery can be successfully used with a LiFePO4 battery is that the voltages correspond reasonably closely for the nominal voltage used in RVs. This has nothing at all to do with stability.

The explanation:

A lead-acid battery runs nominally (less when discharged, more when fully charged) 2 volts per cell, or 12 volts for the six-cells-in-series batteries used in RVs. A LiFePO4 cells runs nominally about 3.2 volts per cells, or 12.8 volts for the four-cells-in-series batteries used to replace lead-acid batteries in RVs. The voltage difference is okay because the LiFePO4 changes less in voltage as it changes in state of charge, so the fully-charged voltage is a decent match. Other lithium-ion cell chemistries usually run around 3.75 volts per cell, so the voltage of three cells in series wouldn't be high enough (only 11.25 V nominally, not much over 12 V fully charged) but the voltage of four cells in series would be too high (15 V nominally, over 16 V to get it fully charged).

If the system were running at a higher voltage, a combination of cells of other chemistries could work. For instance, a "48 volt" lead-acid battery has 24 cells in series, and could be replaced by either 16 LiFePO4 cells in series (51.2 V nominal), or by 13 to 14 NMC or NCA lithium-ion cells in series (48.75 V or 52.5 V nominal)... but 13 or 14 doesn't divide neatly by four to make a usable replacement for a "12-volt" lead-acid battery.

Just like any other lithium-ion battery type, and unlike any lead-acid battery, a LiFePO4 battery needs a management system monitoring individual cell voltages, with high-voltage, low-voltage, high-current, and low (and perhaps high) temperature shutdown features... which is why such a BMS is always included in the lithium battery systems for RVs.

wow you know a lot about these batteries . Would you feel comfortable having a LIFEPO4 inside the trailer? being inside solves a lot of the temperature requirements . I could leave the battery in the storage box but would need to Heat it some way for fall camping. Battle born make a heat pad for this issue , But i thought bringing it inside was a better solution .

[Greg A]

A big portion of the lifepo4 battery installations are interior either in cabin or in basement storage in the big rigs. If the basements are not heated they usually add a heating Matt if deemed necessary. The 5.0, 21, and 19 are all conducive to putting the Lifepo4 batteries under the benches interior. Some of our members have had these installs in operation for some time with no issues, one 19 who AMSolar put his install under DS dinette bench. I’ve seen nothing from any of the installs that have been in place for years that would make me concerned about that being unsafe.
Of greater concern for issues are the 21 and 5.0 trailers that at a minimum don’t have AGM’s or Lithium’s by now under their rear bench.