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Cause of Battery Fire

Heat detectors come in two general forms, one uses a fusible link which melts at a predetermined temperature, then there are dual function type, which use a chamber with a small pinhole to activate on rate of temperature, they too incorporate a fusible link, making them dual purpose, the application depends on environmental conditions.

Smoke detectors also fall into two categories, photo electric and ionization, both can detect smoke, but one may be more sensitive to the particular type of smoke generated, as for the smoke generated for from a LiFePo4 fire, I can't, ar this time definitively answer that question, without further research.

Basically what I'm alluding to is, don't assume because there are protections installed, they will work as intended.

BTW, I am qualified in fire alarm inspection and testing.
 
I don't see any way to use a smoke detector for an externally mounted battery box on a diesel. It would need to be incredibly well sealed to keep out all of the water and particulates. Otherwise it would trigger all the time or foul the sensor.
Single stage heat detector is all I think might work, too much heat rise on a hot interstate drive to use a standard heat rise at 135 degrees. My tires are regularly over that on a long daytime drive in the west.
 
My biggest fear with lifepo4 in the RV... :oops:

I'm surprised HDPE 'starboard' isn't used more often. Impervious to everything and non-conductive. It's used a lot on boats and I suspect that many are unaware of its existence due to that.

I liked this build so much I'm copying its overall design parameters with a few modifications.

Thread link:

20211216_200841-jpg.76040
 
My biggest fear with lifepo4 in the RV... :oops:

I'm surprised HDPE 'starboard' isn't used more often. Impervious to everything and non-conductive. It's used a lot on boats and I suspect that many are unaware of its existence due to that.

I liked this build so much I'm copying its overall design parameters with a few modifications.

Thread link:

20211216_200841-jpg.76040
I’m afraid that HDPE melts at 235 degrees while lithium burns closer to 2000 degrees. I love starboard, and have used it a lot on my boat, but it won’t save you from a fire I’m afraid.
 
My biggest fear with lifepo4 in the RV... :oops:

I'm surprised HDPE 'starboard' isn't used more often. Impervious to everything and non-conductive. It's used a lot on boats and I suspect that many are unaware of its existence due to that.

I liked this build so much I'm copying its overall design parameters with a few modifications.

Thread link:

20211216_200841-jpg.76040

LDPE/UHMW are not dimensionally stable. Over time both of the end of this box will bend in 1/8"-3/16"and the Lexan/Plexigalss will sag.

The wires on he edge of the Lexan/Plaxi is not a great feature.

Tin plated lugs and bus bars aren't used?

Hope the crimps with 3 wires are done properly.

HDPE is stable but to have any rigidity it needs to be a min 3/4". Even 3/4 HDPE will sag if used over the battery. I'd use 1/4"-1/2" HDPE with a 1/2" or 3/4" x 3/4" HDPE bar screwed along the center.

At 1250F it takes 15min to burn through 3/4" plywood.

Ceramic fiber board will prevent plywood or HDPE from burning.....costs about the same as plywood these days.
 
Heat detectors come in two general forms, one uses a fusible link which melts at a predetermined temperature, then there are dual function type, which use a chamber with a small pinhole to activate on rate of temperature, they too incorporate a fusible link, making them dual purpose, the application depends on environmental conditions.

Smoke detectors also fall into two categories, photo electric and ionization, both can detect smoke, but one may be more sensitive to the particular type of smoke generated, as for the smoke generated for from a LiFePo4 fire, I can't, ar this time definitively answer that question, without further research.

Basically what I'm alluding to is, don't assume because there are protections installed, they will work as intended.

BTW, I am qualified in fire alarm inspection and testing.
I like to use fenwal thermostats for rugged environments and positive operation. They are rate compensated and at the lowest temp (140f?) should be good. They come in many flavors including different coatings for different environments. Strictly heat detection but reliable.
 
LDPE/UHMW are not dimensionally stable. Over time both of the end of this box will bend in 1/8"-3/16"and the Lexan/Plexigalss will sag.

The wires on he edge of the Lexan/Plaxi is not a great feature.

Tin plated lugs and bus bars aren't used?

Hope the crimps with 3 wires are done properly.

HDPE is stable but to have any rigidity it needs to be a min 3/4". Even 3/4 HDPE will sag if used over the battery. I'd use 1/4"-1/2" HDPE with a 1/2" or 3/4" x 3/4" HDPE bar screwed along the center.

At 1250F it takes 15min to burn through 3/4" plywood.

Ceramic fiber board will prevent plywood or HDPE from burning.....costs about the same as plywood these days.
Agreed. Mine won't have those features. My T fuse and shunt will be on the base with the bms in a vertical position.

But 'dimensionally stable'? You mean from flex and sag. Emkay, maybe.
Why didn't you post on the guy's thread and tell HIM his build was crap? Seriously. Why?
 
I could tell you stories about voltage leaking from batteries, battery switches and fuse blocks to metal cases. When I make a marine battery boxes it has to be non conductive.
In my own boat ~1993-ish I put two bolts through the helm support plywood of my closed-bow 14’ boat - one for a positive terminal post, one for negative. About 4” apart iirc

A few years later I was having some mild battery drain issues and was looking under the foredeck when I saw wetness running along the plywood. I touched it, it wasn’t wet!???
Got a flashlight and examined closely only to discover that a silvery gray metallic something was ‘plating’ the plywood along late growth grain of the wood. While it wasn’t wet or water stained, apparently there was enough moisture to facilitate electrolytic migration of tin or zinc or electrical solder from the electrical connections of one bolt to the other bolt, heavier nearer the negative side. Not even close to a “peelable” thickness but visually it was there. Blew my mind.

That completely changed my thinking on a lot of things.

I’d probably not use plywood without a substantial plastic liner for any battery box and a cover over the conductors LOL
 
Why didn't you post on the guy's thread and tell HIM his build was crap? Seriously. Why?

Because I've see stuff like this ?.......ALLOT!
In my own boat ~1993-ish I put two bolts through the helm support plywood of my closed-bow 14’ boat - one for a positive terminal post, one for negative. About 4” apart iirc

A few years later I was having some mild battery drain issues and was looking under the foredeck when I saw wetness running along the plywood. I touched it, it wasn’t wet!???
Got a flashlight and examined closely only to discover that a silvery gray metallic something was ‘plating’ the plywood along late growth grain of the wood. While it wasn’t wet or water stained, apparently there was enough moisture to facilitate electrolytic migration of tin or zinc or electrical solder from the electrical connections of one bolt to the other bolt, heavier nearer the negative side. Not even close to a “peelable” thickness but visually it was there. Blew my mind.

That completely changed my thinking on a lot of things.

I’d probably not use plywood without a substantial plastic liner for any battery box and a cover over the conductors LOL
 
In my own boat ~1993-ish I put two bolts through the helm support plywood of my closed-bow 14’ boat - one for a positive terminal post, one for negative. About 4” apart iirc

A few years later I was having some mild battery drain issues and was looking under the foredeck when I saw wetness running along the plywood. I touched it, it wasn’t wet!???
Got a flashlight and examined closely only to discover that a silvery gray metallic something was ‘plating’ the plywood along late growth grain of the wood. While it wasn’t wet or water stained, apparently there was enough moisture to facilitate electrolytic migration of tin or zinc or electrical solder from the electrical connections of one bolt to the other bolt, heavier nearer the negative side. Not even close to a “peelable” thickness but visually it was there. Blew my mind.

That completely changed my thinking on a lot of things.

I’d probably not use plywood without a substantial plastic liner for any battery box and a cover over the conductors LOL

When we use plywood in any environment that is not heated 24/7 the inside get epoxy / 4oz cloth / epoxy. The outside get 2 coats of epoxy.
 
Absolutely, there is 1/16" HDPE sheets inbetween every cell, and the threaded rods are also heat shrinked to prevent shorting.

EDIT: Sorry for the thread jacking lol
Heat shrink is soft. Threaded rod will cut through it.
 
But 'dimensionally stable'? You mean from flex and sag. Emkay, maybe.

Post #2 here......

 
In my own boat ~1993-ish I put two bolts through the helm support plywood of my closed-bow 14’ boat - one for a positive terminal post, one for negative. About 4” apart iirc

A few years later I was having some mild battery drain issues and was looking under the foredeck when I saw wetness running along the plywood. I touched it, it wasn’t wet!???
Got a flashlight and examined closely only to discover that a silvery gray metallic something was ‘plating’ the plywood along late growth grain of the wood. While it wasn’t wet or water stained, apparently there was enough moisture to facilitate electrolytic migration of tin or zinc or electrical solder from the electrical connections of one bolt to the other bolt, heavier nearer the negative side. Not even close to a “peelable” thickness but visually it was there. Blew my mind.

That completely changed my thinking on a lot of things.

I’d probably not use plywood without a substantial plastic liner for any battery box and a cover over the conductors LOL

People produce videos of "dendrites" growing across a PCB in real time.

I'm following "creepage and clearance" rules for a PCB I designed that will provide some EMI filtering of mains power. It needs to work for 120/208Y and 230/400Y. I first selected 0.156" pitch connectors rated for 600V, but realized I couldn't meet "creepage" rules for distance across surface of PCB unless I either used a higher grade of material than FR4, or had slots milled between all pins. I was able to use 0.25" pitch connectors instead and stick with FR4.

The creepage and clearance table covered some common material types (graded by "tracking index"), but didn't extend down to "Marine Plywood" :ROFLMAO:

 
I found white acrylic rod/tube extrusion for the compression rods I’m pretty excited about. And various thicknesses of clear lexan for shields and covers.
I’m debating on blue or green led strips to light it up.
 
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